Watch glossary A–Z

Watch papers, auction catalogues and listings are full of trade terms. Here each one is explained briefly, with the terms it is often confused with and the brands in our register where you will meet it.

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18k goldMaterials

18k (18-carat) gold contains 18 parts gold out of 24 (75 %) and is marked 750. It is the standard for Swiss gold watches because it balances rich colour with enough hardness for daily wear. The remaining 25 % – silver, copper, palladium and others – determines whether the alloy is yellow, rose or white. Look for 750 and an official hallmark on the case, lugs or caseback to confirm solid gold rather than plating.

Also called: 18 carat gold, 18ct gold, 750 gold, 18K

See also: Gold, Precious metal hallmark, Yellow gold, Rose gold, Gold-plated

Brands: Concord, Delma, Genus, West End Watch Co.

Guide: How much is my watch worth?

24-hour bezelCase

A 24-hour bezel is marked from 1 to 24 around the dial and is read with a 24-hour hand. By turning it you can show a second or third time zone at a glance. It is the hallmark of GMT watches; two-colour versions, for example blue-red or black-red, separate day and night hours and have earned nicknames among collectors.

Also called: GMT bezel, 24h bezel

See also: GMT, GMT watch, Dual time, Bidirectional bezel, Ceramic bezel insert

Brands: Glycine, Zodiac

316L steelMaterials

316L is the standard grade of austenitic stainless steel used for most watch cases and bracelets. The "L" stands for low carbon, which improves corrosion resistance, and the molybdenum content helps against salt water and sweat. It is hypoallergenic for most wearers, though it does contain nickel. A watch marked simply "stainless steel" is almost always 316L or a close variant.

Also called: 316L stainless steel, surgical steel, 1.4404, 1.4435

See also: Stainless steel, 904L steel, Oystersteel, Titanium

904L steelMaterials

904L is a highly alloyed stainless steel with more chromium, nickel and molybdenum than 316L, giving greater corrosion resistance and a slightly brighter polish. It is harder to machine, so few brands use it. Rolex is the best-known user and switched its steel models to it from the 1980s onwards, now calling it Oystersteel. Some homage and fake watches advertise "904L" as a selling point, which proves nothing about authenticity.

Also called: 904L stainless steel, 1.4539

See also: 316L steel, Oystersteel, Stainless steel, Replica watch

Guide: Real or fake?

A

AccuracyPrecision and certificates

How closely a watch keeps time, usually expressed as gain or loss in seconds per day. A new mechanical watch typically runs within about ±10 seconds per day, while COSC chronometers must stay within −4/+6 seconds, and a quartz watch is usually accurate to a few seconds per month. Poor accuracy in a mechanical watch often indicates a need for service or magnetisation.

Also called: rate, timekeeping, precision

See also: Seconds per day, Timegrapher, Regulation, COSC, Magnetism

Guide: Watch condition

Acrylic crystalCase

An acrylic crystal is made of plastic (PMMA, often called Plexiglas). It was standard on most watches until sapphire became common. It is light, slightly warm in appearance, distorts the dial edge when domed and scratches easily, but light scratches can be polished out. On vintage watches the original acrylic crystal is part of the period look and is preferred by collectors.

Also called: plexiglass, plexi, plastic crystal, PMMA

See also: Crystal, Hesalite, Domed crystal, Box crystal, Vintage

Aftermarket partsMarket and collecting

Parts not made by the original manufacturer, such as non-original bezels, dials, diamond settings, crystals or bracelets fitted after the watch left the factory. They can look convincing but usually lower the value, and the manufacturer may refuse to service a watch with aftermarket parts. Listings should say clearly whether every part is original.

Also called: aftermarket, non-original parts, generic parts, AM

See also: Franken watch, Parts replacement, Redial, Authentication

Brands: Rolex, Audemars Piguet, Chopard, Franck Muller, Omega, Piaget, Richard Mille

Guide: Real or fake?

Alarm watchComplications

A mechanical watch with an alarm that rings at a set time, usually with its own barrel wound by a second crown and a hand to set the alarm time. A hammer strikes a membrane or the case to make the sound. Classic Swiss examples include the Vulcain Cricket and the Jaeger-LeCoultre Memovox.

Also called: mechanical alarm, réveil, alarm complication

See also: Complication, Barrel, Crown, Mechanical watch

Brands: Jaeger-LeCoultre, Auguste Reymond, Eterna

Guide: How much is my watch worth?

Alligator strapStraps and bracelets

An alligator strap is made from alligator skin, recognisable by its large, regular rectangular scales, especially along the centre. It is the traditional strap for high-end dress watches. Crocodile is similar but has smaller, more irregular scales and pores in each scale. Exotic leathers fall under CITES rules, which can complicate shipping a watch with such a strap across borders.

Also called: croc strap, crocodile strap, Mississippiensis strap, gator strap

See also: Leather strap, Strap, Dress watch, Calatrava, Tang buckle

Alpha handsDial and hands

Alpha hands are slim hands that widen slightly near the centre and taper to a sharp point, resembling an elongated leaf or the Greek letter alpha. They are found on dress and vintage-style watches and offer an elegant, understated look. They are close relatives of leaf and dauphine hands.

Also called: alpha

See also: Leaf hands, Dauphine hands, Baton hands, Dress watch

AM/PM indicatorComplications

A small hand or window that shows whether the displayed time is before or after noon. It is common on dual-time watches, whose second time zone is often shown on a 12-hour scale, and on calendar watches, where knowing midnight from noon matters when setting the date.

Also called: AM/PM display, 24-hour indicator

See also: Day-night indicator, Dual time, GMT, Perpetual calendar

Guide: How much is my watch worth?

AmplitudePrecision and certificates

The angle through which the balance wheel swings from its rest position, measured in degrees on a timegrapher. In a healthy, fully wound modern watch it is typically around 270–310° dial up; noticeably lower values often point to old oil, a weak mainspring or wear. Amplitude is one of the best quick indicators of whether a watch needs servicing.

Also called: balance amplitude, swing

See also: Timegrapher, Beat error, Balance wheel, Service, Isochronism

Guide: Watch condition

AnglageMovement

Anglage is the bevelling and polishing of the edges of bridges, levers and other parts at an angle, usually around 45 degrees. Done by hand it is time-consuming, especially on inward-pointing angles that machines cannot make. Fine hand anglage is a hallmark of top-level watchmaking and of quality seals such as the Geneva Seal.

Also called: bevelling, chamfering, beveled edges

See also: Movement finishing, Black polishing, Geneva Seal, Bridge

Guide: How much is my watch worth?

Annual calendarComplications

A calendar that automatically handles months of 30 and 31 days and needs correcting only once a year, at the end of February. It sits between a simple date and a perpetual calendar in complexity and price. Patek Philippe introduced and patented the annual calendar in wristwatch form in 1996.

Also called: quantième annuel

See also: Perpetual calendar, Complete calendar, Triple calendar, Complication

Brands: Berneron, Laurent Ferrier

Guide: How much is my watch worth?

Anti-reflective coatingCase

An anti-reflective coating is a thin layer applied to the crystal that reduces glare and improves legibility. It may be on the inside, the outside or both. A bluish or purplish tint when the crystal is tilted is typical. An outside coating can wear or scratch over time, leaving patchy marks that look like scratches in the glass itself.

Also called: AR coating, anti-glare coating, non-reflective coating

See also: Sapphire crystal, Crystal, Domed crystal, Crystal replacement

AntimagneticPrecision and certificates

Describes a watch that resists magnetic fields. The international standard ISO 764 requires a watch to withstand 4,800 A/m (about 60 gauss); special watches use a soft-iron inner case or non-magnetic materials such as silicon to resist far more. Older dials marked “antimagnetic” usually only meet basic protection and can still become magnetised.

Also called: anti-magnetic, amagnetic, magnetic resistance

See also: Magnetism, Gauss, Faraday cage case, Silicon hairspring, Master Chronometer

Brands: IWC Schaffhausen, Alpina, Doxa, Oris, Tissot

Guide: Watch condition

Applied indicesDial and hands

Applied indices are separate hour markers made of metal, fixed onto the dial with small pins or adhesive. They stand out in relief and reflect light, which gives a richer, higher-quality look than printed markers. On genuine luxury watches they are precisely aligned and well finished. Loose, misaligned or rough indices suggest damage or a fake.

Also called: applied markers, applied hour markers, appliqué indices

See also: Printed indices, Dial, Lume, Counterfeit watch

Arabic numeralsDial and hands

Arabic numerals are the familiar digits 1 to 12 used to mark the hours on a dial. They give a clear, sporty or military look and are typical of pilot and field watches. They can be printed, applied or luminous. Some dials show only a few numerals, such as 3, 6, 9 and 12, combined with batons or dots.

Also called: arabic numbers, arabic hour markers

See also: Roman numerals, Breguet numerals, Pilot watch, Field watch

Astronomical complicationComplications

Any function that shows celestial phenomena, such as the moon phase, a sky chart, sunrise and sunset times, the equation of time, sidereal time or the zodiac. They are typically used in high-end watches and grand complications. Precise astronomical displays require complex gearing and are a sign of high craftsmanship.

Also called: astronomical watch, astronomic complication, sky chart

See also: Moon phase, Equation of time, Tide indicator, Grand complication

Guide: Most valuable Swiss watches

ATMService and water resistance

Atmosphere, a unit of pressure used to state water resistance, often printed on dials or casebacks (e.g. "10 ATM"). As a rule of thumb, 1 atm corresponds to about 10 metres of water pressure. The figure is measured in static laboratory tests, so it does not mean the watch can be taken to that depth.

Also called: atmospheres, atm.

See also: Water resistance, Bar, Pressure test, ISO 6425

Guide: Watch condition

AuthenticationMarket and collecting

Checking whether a watch is genuine and original. A specialist compares the case, dial, hands, movement, engravings and serial and reference numbers with the manufacturer's specifications and usually opens the caseback. Results can range from genuine and original to genuine with replaced parts or fake. Manufacturers and independent experts offer this service.

Also called: authenticity check, verification, legit check

See also: Counterfeit watch, Franken watch, Serial number, Extract from the Archives, Watch appraisal

Guide: Real or fake?

Authorised dealer (AD)Market and collecting

A retailer officially appointed by a watch brand to sell its new watches and issue its warranty. Buying from an AD guarantees authenticity and the full manufacturer's warranty. For in-demand models, ADs often keep waiting lists or give priority to existing clients, which is why the same watch can cost more on the secondary market than at retail.

Also called: AD, authorized dealer, official retailer, concessionaire

See also: Grey market, Waiting list, Retail price, Warranty card, Boutique edition

Brands: Cyrus Genève, DeWitt

Guide: Real or fake?

Automatic watchTypes of movement

An automatic watch is a mechanical watch that winds itself through a rotor moved by the wearer's wrist. Most can also be wound by the crown. If not worn, it stops after its power reserve runs out. 'Automatic' on a dial does not mean battery-powered; that would be a quartz watch.

Also called: automatic, self-winding watch

See also: Self-winding, Rotor, Mechanical watch, Power reserve, Manual winding

B

B-UhrTypes of watch

B-Uhr (Beobachtungsuhr, "observation watch") is the German WWII navigator's watch issued to the Luftwaffe: a very large case of about 55 mm, a big crown, a flat dial in "type A" or "type B" layout and a long strap worn over the flight jacket. Makers included A. Lange & Söhne, IWC, Laco, Stowa and Wempe. Originals are rare, so many on the market are later reproductions or assembled pieces.

Also called: Beobachtungsuhr, B-Uhren, observation watch, navigator watch

See also: Flieger watch, Pilot watch, Military watch, Provenance, Franken watch

Guide: Real or fake?

Balance cockMovement

The balance cock is the bridge that holds the balance wheel in place, supported at only one end. It usually carries the upper jewel, the shock protection and often the regulator. In antique pocket watches it was frequently hand-engraved. Scratches or marks around the balance cock can hint at clumsy repairs.

Also called: balance bridge, cock

See also: Balance wheel, Bridge, Shock protection, Regulator

Guide: Watch condition

Balance wheelMovement

The balance wheel is the oscillating wheel that, together with the hairspring, acts as the timekeeping heart of a mechanical watch. It swings back and forth several times per second. Its material, weight and adjustment determine stability. Some balances carry screws or weights for fine regulation without a regulator index.

Also called: balance, oscillator

See also: Hairspring, Free-sprung balance, Glucydur, Frequency, Balance cock

Brands: Rudis Sylva, Frederique Constant, MB&F, Romain Gauthier

BarService and water resistance

A unit of pressure used, like atm, to indicate water resistance; 1 bar is roughly equal to 1 atm, or about 10 metres of water. A watch marked "10 bar" has passed a test at that pressure, not a dive to 100 metres. The rated value assumes intact gaskets and a closed crown.

Also called: bar rating

See also: ATM, Water resistance, Pressure test, Gasket

Guide: Watch condition

BarrelMovement

The barrel is the drum-shaped housing that contains the mainspring. Its toothed rim drives the first wheel of the gear train as the spring unwinds. Barrel size and spring length largely determine the power reserve. Some movements use two or more barrels to run longer or more evenly.

Also called: mainspring barrel, going barrel

See also: Mainspring, Twin barrel, Power reserve, Going train

Baton handsDial and hands

Baton hands are straight, slim rectangular hands, sometimes with a pointed tip. Their minimalist look suits dress watches and modern designs. Wider versions may carry lume. They are one of the simplest hand styles and match baton or stick markers on the dial.

Also called: stick hands, batons, baton

See also: Dauphine hands, Alpha hands, Sword hands, Printed indices

BatteryTypes of movement

Quartz and other electronic watches run on a small button cell, usually silver oxide, which typically lasts a few years. A flat battery should be replaced promptly, because leaking cells can corrode the movement. When buying a quartz watch, check for corrosion in the battery area and that the watch keeps running after a battery change.

Also called: cell, button cell, watch battery

See also: Quartz watch, Solar watch, Kinetic watch, Service

Guide: Watch condition

Beads-of-rice braceletStraps and bracelets

A beads-of-rice bracelet has rows of small, rounded oval links resembling grains of rice, typically five or more across. It was popular on Swiss watches from the 1950s to the 1970s, including models by Omega and others, and is again offered on some modern pieces. The many small links make it comfortable but prone to stretch on vintage examples. Original period bracelets are sought-after.

Also called: BOR bracelet, rice bead bracelet, beads of rice

See also: Bracelet, Bracelet stretch, Mesh bracelet, Vintage

Guide: How much is my watch worth?

Beat errorPrecision and certificates

The asymmetry between the balance’s swings to the left and to the right, measured in milliseconds on a timegrapher. A small beat error, typically under about 0.5 ms, is considered good. A high value can make a watch stop more easily or run less regularly and is corrected by a watchmaker when the watch is regulated.

Also called: beat, out of beat

See also: Timegrapher, Amplitude, Regulation, Balance wheel

Guide: Watch condition

Beat rateMovement

Beat rate is the number of ticks a mechanical watch makes, usually given per hour or per second, and it equals the balance's vibrations. A 28,800 vph watch ticks eight times a second. A timegrapher needs the correct beat rate to measure a watch, and an unexpected rate can reveal a movement that does not belong in the case.

Also called: beats per hour, bph, tick rate

See also: Frequency, Vibrations per hour, Timegrapher, Beat error

Guide: Real or fake?

Bevel (chamfer)Case

A bevel, or chamfer, is a narrow angled surface where two faces of a case or bracelet meet, often mirror polished to contrast with brushed areas. Crisp, even bevels on lugs and case edges are a strong sign that a case has not been overpolished. When a case is polished heavily, the bevels round off or disappear, reducing its collector value.

Also called: chamfer, case bevel, polished bevel

See also: Mirror polish, Brushed finish, Lug, Sharp case, Overpolished case

Guide: Watch condition

BezelCase

The bezel is the ring around the crystal on the top of the case. It may be fixed and plain, polished, fluted or engraved, or it may rotate and carry a scale for timing, a second time zone or a tachymeter. On sports watches the bezel insert is a key detail for originality: faded, correct inserts can be valuable, while replacements lower the value.

Also called: lunette

See also: Rotating bezel, Ceramic bezel insert, Ghost bezel, Tachymeter, Crystal

Guide: Real or fake?

Bidirectional bezelCase

A bidirectional bezel can be turned both clockwise and anticlockwise, with or without click stops. It is common on GMT and world-time watches, where a 24-hour scale is set to a second time zone, and on some pilot and navigation watches with a slide rule or compass scale. It is not considered suitable as a dive timer.

Also called: bi-directional bezel, two-way bezel

See also: Rotating bezel, 24-hour bezel, GMT, Unidirectional bezel, Slide-rule bezel

Bidirectional windingMovement

Bidirectional winding means the rotor of an automatic watch winds the mainspring in both directions of rotation, using reverser wheels or a system such as Seiko's Magic Lever. It generally winds more efficiently than unidirectional winding, although some respected calibres wind in one direction only. It says little about quality on its own.

Also called: bi-directional winding, two-way winding

See also: Rotor, Reverser wheel, Magic Lever, Automatic watch

Big dateDial and hands

A big date shows the date in an oversized window, usually with two separate discs or a disc and a cross for tens and units. It is much easier to read than a standard date window and requires a more complex mechanism. Big dates are found on dress watches and sports models and are sometimes called outsize or panorama date by brands.

Also called: large date, grande date, outsize date, panorama date

See also: Date window, Day-date display, Complication, Annual calendar

Brands: Mido

BioceramicMaterials

Bioceramic is Swatch's name for its case material made of roughly two-thirds ceramic powder and one-third bio-sourced plastic derived from castor oil. It became widely known through the Omega × Swatch MoonSwatch and is also used for other Swatch models. It is lighter and more scratch-resistant than ordinary plastic but is not the same as the high-tech ceramic used in luxury watches.

Also called: Swatch Bioceramic, bio-ceramic

See also: Ceramic, Cermet, Sports watch, Hype watch

Brands: Swatch

Guide: Swiss watch brands A–Z

Black polishingMovement

Black polishing is a mirror polish so perfectly flat that the surface looks black from most angles and lights up only at one. It is done by hand on steel parts such as screws, springs and levers and takes a great deal of time. It is found only in high-end movements and is a strong sign of genuine fine finishing.

Also called: mirror polishing, specular polishing, poli noir

See also: Movement finishing, Anglage, Blued screws, Geneva Seal

Guide: How much is my watch worth?

Blued screwsMovement

Blued screws are steel screws heated until their surface turns a deep blue, a traditional technique that adds corrosion protection and a decorative contrast. True heat-bluing has a slightly iridescent shade; chemically coloured screws look flatter. Mismatched or scratched screw heads can point to repairs or replacement parts.

Also called: thermally blued screws, heat-blued screws

See also: Movement finishing, Black polishing, Breguet hands, Aftermarket parts

Guide: Watch condition

Boutique editionMarket and collecting

A model or variant sold only in the brand's own boutiques, not through regular authorised dealers. Boutique editions can be limited or unlimited and often differ from the standard model in dial colour, materials or details. Their restricted distribution can make them harder to find on the secondary market.

Also called: boutique exclusive, boutique-only edition

See also: Limited edition, Authorised dealer (AD), Numbered edition, Retail price

Guide: Most valuable Swiss watches

Box and papersMarket and collecting

Shorthand in listings for a watch sold with its original box and documents, above all the warranty card or certificate issued at the time of sale. Papers that carry the matching serial number support authenticity and provenance and usually add value. "Watch only" means neither box nor papers are included; "papers only" means the box is missing.

Also called: B&P, box & papers, boxed and papered

See also: Full set, Warranty card, Full-set premium, Provenance

Guide: How much is my watch worth?

Box crystalCase

A box crystal has tall vertical sides and a flat or slightly curved top, so it rises above the bezel like the lid of a box. It is known from vintage chronographs and dive watches and is now reproduced in sapphire on many heritage re-editions. Viewed from the side, the high wall gives a distinctive, distorted view of the dial edge.

Also called: box sapphire, glass box crystal, top hat crystal

See also: Domed crystal, Acrylic crystal, Crystal, Case thickness

BraceletStraps and bracelets

A bracelet is a metal watchband made of links, usually in steel, titanium, gold or platinum, closed with a folding clasp. Original bracelets carry the brand's reference number on the clasp and correctly coded end links, and they matter a lot for value – a vintage watch with its original bracelet can be worth much more. Loose pins, stretch and missing links are typical wear points.

Also called: metal bracelet, link bracelet, metal band

See also: Strap, End links, Folding clasp, Bracelet stretch, Integrated bracelet case

Guide: How much is my watch worth?

Bracelet stretchStraps and bracelets

Bracelet stretch is the wear-related lengthening and sagging of a metal bracelet as pins and holes wear over years of use. A stretched bracelet hangs in a curve when the watch is held horizontally and shows gaps between the links. Moderate stretch is normal on vintage pieces, but heavy stretch lowers the condition grade and can be only partly repaired by replacing pins or links.

Also called: stretch, bracelet sag, link stretch

See also: Bracelet, Hollow links, Folded links, Honest wear, Service

Guide: Watch condition

Breguet handsDial and hands

Breguet hands are slim hands with a hollow circle, or moon, near the tip, often made of blued steel. They are named after Abraham-Louis Breguet, who popularised the style. They are typical of classic dress watches and are often combined with Breguet numerals and guilloché dials. Many brands use them today.

Also called: pomme hands, moon hands, Breguet-style hands

See also: Breguet numerals, Blued screws, Guilloché dial, Dress watch

Brands: Breguet

Breguet numeralsDial and hands

Breguet numerals are a stylised form of Arabic numerals with elegant curves and slanted strokes, named after the watchmaker Abraham-Louis Breguet. They are typical of classic dress watches, often combined with Breguet hands and guilloché dials. Today many brands use them, not just Breguet. They are a style rather than a brand term.

Also called: Breguet numbers, Breguet-style numerals

See also: Breguet hands, Arabic numerals, Guilloché dial, Dress watch

Breguet overcoilMovement

A Breguet overcoil is a hairspring whose outer end is lifted and bent back over the spiral, an improvement devised by Abraham-Louis Breguet. It helps the spring breathe evenly, improving isochronism and positional accuracy. It is found in many high-quality movements and, in some, made from silicon in a similar form.

Also called: overcoil, Breguet spring, Breguet hairspring

See also: Hairspring, Isochronism, Positional error, Balance wheel

Brands: Breguet, Simon Brette

BridgeMovement

A bridge is a plate fixed to the mainplate with screws and pins, holding one or more wheels in place between the two. The shape and arrangement of the bridges give a movement its look. On fine movements bridges carry Côtes de Genève stripes and bevelled, polished edges, which you can see through a display caseback.

Also called: cock, movement bridge

See also: Mainplate, Balance cock, Côtes de Genève, Anglage, Display caseback

Guide: Watch condition

BronzeMaterials

Bronze is a copper alloy, usually with tin or aluminium, used mainly for dive and tool watches with a vintage nautical look. It develops a patina over time – from a warm brown to green spots – which owners often welcome and which makes every piece look different. Because bronze can discolour the skin, casebacks are usually made of steel or titanium. Patina can be cleaned, so it is not a reliable sign of age.

Also called: CuSn, aluminium bronze, bronze case

See also: Patina, Dive watch, Stainless steel, Tool watch

Brands: Maurice de Mauriac, Oris, Rado, Singer Reimagined, Traser

Guide: Watch condition

Brushed finishCase

A brushed finish, also called satin finish, has fine parallel lines that give metal a matte, silky surface. It is used on cases, bezels and bracelets and hides small scratches well. Many cases combine brushed and polished surfaces. The original pattern and the sharp line between finishes are lost when a case is polished carelessly, which lowers the value.

Also called: satin finish, satin-brushed, brushing, satinage

See also: Mirror polish, Overpolished case, Bevel (chamfer), Honest wear

Guide: Watch condition

Bund strapStraps and bracelets

A Bund strap is a leather strap with a wide pad that sits underneath the watch, separating the case from the skin. It is associated with German military use, where the pad protected the wrist from a cold or hot metal case and the case from sweat. Today it is a style choice for pilot and military watches. "Bund" refers to the German armed forces.

Also called: Bund band, Bundeswehr strap, pad strap

See also: Leather strap, Pilot watch, Military watch, Flieger watch, NATO strap

Buyer's premiumMarket and collecting

A fee charged by the auction house to the buyer on top of the hammer price, calculated as a percentage that often decreases in bands for higher amounts. Rates differ between auction houses and are stated in the conditions of sale. Sellers usually pay a separate commission, so the seller receives considerably less than the published result.

Also called: auction premium, buyer premium, BP

See also: Hammer price, Estimate, Provenance

Guide: Sell a luxury watch

C

CalatravaTypes of watch

Calatrava is Patek Philippe's line of round, simple dress watches, beginning with Ref. 96 in 1932, and also the name of the Calatrava cross used as Patek's emblem. The style – clean dial, slim case, often only hours, minutes and small seconds – became the archetype of the classic dress watch. The term is sometimes used generically for this style, but strictly it is a Patek Philippe model name.

Also called: Patek Calatrava, Calatrava cross

See also: Dress watch, Small seconds, Manual winding, Reference number

Brands: Patek Philippe

Guide: Swiss watch brands A–Z

CalibreMovement

Calibre is the watch industry's word for a specific movement design, usually identified by a maker's name and number. It originally referred to the size and layout of a movement. Knowing the calibre tells you how the watch is built, how easy it is to service and whether it is the correct movement for that model.

Also called: caliber, cal., movement type

See also: Movement, Calibre number, Ébauche, In-house movement

Guide: Real or fake?

Calibre numberMovement

The calibre number is the code that identifies a movement type, for example Rolex 3135 or ETA 2824-2. It is usually engraved on the movement and appears in catalogues and papers. Checking that the calibre number matches the model and reference is one of the basic steps in judging authenticity and originality.

Also called: caliber number, cal. no., movement number

See also: Calibre, Reference number, Serial number, Movement, Franken watch

Brands: Alpina, Movado, Omega, Roamer, Patek Philippe

Guide: Real or fake?

Cam-actuated chronographMovement

A cam-actuated chronograph uses a flat cam and levers instead of a column wheel to control start, stop and reset. It is simpler and cheaper to make and very robust, as in the Valjoux 7750. Pushers feel firmer. It is not a defect, but column-wheel versions are usually rated higher by collectors.

Also called: cam chronograph, cam-switching chronograph, shuttle cam

See also: Column wheel, Chronograph, Valjoux 7750, Horizontal clutch

Carbon fibreMaterials

Carbon fibre is a composite of thin carbon filaments embedded in resin, valued for being very light and strong. In watches it appears as dial material (with its typical woven pattern), as case material or in layered composites. Different makers use their own processes and trade names. Damage such as cracks or delamination cannot be repaired, and a printed "carbon look" on cheap dials is not the real material.

Also called: carbon fiber, carbon composite, CFRP

See also: Forged carbon, Ceramic, Cermet, Titanium, Sports watch

Brands: Norqain

CarrouselComplications

A rotating carriage for the escapement, similar in purpose to the tourbillon, invented by Bahne Bonniksen in the 1890s. Unlike a tourbillon, the carriage is driven by a separate wheel rather than directly through the escapement. Blancpain revived the carrousel in wristwatches, and it is often confused with a tourbillon in listings.

Also called: karrusel, karussel, carousel

See also: Tourbillon, Flying tourbillon, Escapement, Positional error

Guide: Most valuable Swiss watches

CaseCase

The case is the outer housing that holds and protects the movement, dial and hands. It consists of the middle part with the lugs, the bezel, the caseback, the crystal and the crown. Material, shape and condition of the case strongly influence a watch's value: original, unpolished cases with crisp edges are prized, while heavily polished or replaced cases lower the price.

Also called: watch case, case middle, carrure

See also: Case diameter, Caseback, Bezel, Lug, Overpolished case

Guide: Watch condition

Case diameterCase

The case diameter is the width of the case measured across, usually excluding the crown. It is given in millimetres and is the first size figure in most listings. Fashion has changed over time: many vintage men's watches measure 33–36 mm, modern sports watches often 39–42 mm. Diameter alone can mislead, so check lug-to-lug length and thickness as well.

Also called: case size, diameter

See also: Case, Lug-to-lug, Case thickness, Mid-size watch

Brands: Philippe Dufour, TAG Heuer, Tissot

Guide: How much is my watch worth?

Case thicknessCase

Case thickness is the height of the watch from the caseback to the top of the crystal, measured in millimetres. It depends on the movement, the type of crystal and the water resistance. Thin watches are seen as elegant and technically demanding, especially with complications, while thick cases are typical of dive and tool watches. A domed crystal or display back adds to the figure.

Also called: case height, thickness

See also: Case diameter, Domed crystal, Dress watch, Display caseback

CasebackCase

The caseback closes the case at the back and protects the movement. It may be screwed down, snapped on or held by screws, and solid or fitted with a sapphire window. Inside or outside, it often carries the reference number, serial number, material marks and maker's stamps, which are important for identification and authenticity.

Also called: case back, back cover, back

See also: Screw-down caseback, Snap-on caseback, Display caseback, Caseback engraving, Reference number

Brands: Edox, Adriatica, Alpina, Carl F. Bucherer, Arnold & Son, Blancpain, Chronoswiss, Concord

Guide: Real or fake?

Caseback engravingCase

Caseback engravings are markings on the back of the case: brand, reference, material, water resistance, serial number or a personal dedication. Personal or presentation engravings reduce value for most buyers, unless they link the watch to a notable owner or event and can be documented. Shallow, uneven or misspelt factory engravings are warning signs of a fake.

Also called: engraved caseback, dedication engraving, presentation engraving

See also: Caseback, Provenance, Serial number, Reference number, Counterfeit watch

Brands: Fortis, Gérald Genta, Zeno-Watch Basel, Hublot, Movado

Guide: Real or fake?

Cathedral handsDial and hands

Cathedral hands have an ornate, openwork shape that recalls the windows of a Gothic cathedral. They were typical of early military and pilot wristwatches and pocket watches, often filled with luminous material. Today they appear on vintage-style models. Original cathedral hands with matching lume add to the value of an early watch.

Also called: cathedral

See also: Breguet hands, Lume, Trench watch, Pocket watch

CeramicMaterials

In watchmaking, ceramic usually means high-tech zirconium oxide, sintered into cases, bezels or bezel inserts. It is very scratch-resistant, light, hypoallergenic and keeps its colour, but it can crack or chip if dropped on a hard surface. Ceramic bezel inserts are now standard on many sports watches; colours other than black and white were long hard to produce. Damage cannot be polished out, so chipped parts must be replaced.

Also called: high-tech ceramic, zirconium oxide, zirconia, ZrO2, Cerachrom

See also: Ceramic bezel insert, Cermet, Bioceramic, Sapphire case, Bezel

Brands: Rado, Hublot, Formex, IWC Schaffhausen, Mauron Musy

Guide: Watch condition

Ceramic bezel insertCase

A ceramic bezel insert is the scale ring of a bezel made of hard ceramic instead of aluminium. It resists scratches and does not fade in sunlight, so it keeps its colour for decades. Its glossy surface and engraved, often filled numerals are typical of modern sports watches. It can crack if dropped, and replacement is expensive.

Also called: ceramic insert, Cerachrom

See also: Bezel, Ceramic, Ghost bezel, 24-hour bezel

CermetMaterials

Cermet is a composite of ceramic and metal, combining the hardness of ceramic with some of the toughness and lower weight of a metal. In watches it is used mainly for bezels and occasionally for cases, often with a matte grey look. It is less common than pure ceramic and the exact composition varies by maker. Like ceramic, it resists scratches well but cannot easily be refinished.

Also called: ceramic-metal composite, ceramic metal matrix composite

See also: Ceramic, Titanium, Carbon fibre, Bezel

Brands: Rado

Certified pre-owned (CPO)Market and collecting

A pre-owned watch that has been checked, serviced if necessary and resold by the manufacturer or an authorised dealer with a new warranty. Examples include official programmes from several Swiss brands. CPO watches usually cost more than comparable private sales, but offer greater certainty about authenticity and condition.

Also called: CPO, certified used

See also: Pre-owned, Authorised dealer (AD), Authentication, Service

Brands: Rolex, Speake-Marin

Guide: Sell a luxury watch

Chapter ringDial and hands

The chapter ring is the band on or around the dial that carries the hour markers or minute scale. It can be printed on the dial itself or be a separate raised ring, sometimes angled. On skeleton watches, the chapter ring is often the only remaining part of the dial. The term comes from clockmaking.

Also called: chapter, hour ring, minute ring

See also: Rehaut, Railway minute track, Dial, Skeleton dial

ChronographComplications

A watch with a built-in stopwatch: pushers start, stop and reset a seconds hand that runs independently of the time display, while subdials count elapsed minutes and often hours. Not to be confused with “chronometer”, which is a precision certificate. Whether the chronograph is driven by a column wheel or a cam, and whether it still works properly, both affect value.

Also called: chrono, stopwatch function

See also: Column wheel, Cam-actuated chronograph, Flyback chronograph, Rattrapante (split-seconds chronograph), Tachymeter

Brands: TAG Heuer, Singer Reimagined, Breitling, Angelus, Eberhard & Co., Fortis, Gallet, Hublot

Guide: How much is my watch worth?

ChronometerPrecision and certificates

A watch whose movement has passed an official precision test; in Switzerland the word may only be used for watches certified by the COSC or a comparable body. The term is often confused with “chronograph”, the stopwatch function. A chronometer certificate or dial inscription such as “Officially Certified Chronometer” is a plus, but original papers matter more than the word on the dial.

Also called: certified chronometer, officially certified chronometer, chronomètre

See also: COSC, Chronometer certificate, Master Chronometer, Observatory chronometer, Chronograph

Brands: Akrivia / Rexhep Rexhepi, Omega, Arnold & Son, F.P. Journe, Formex, Mido, Simon Brette, Ball Watch

Guide: How much is my watch worth?

Chronometer certificatePrecision and certificates

The document issued for a movement that has passed a chronometer test, such as the COSC test, often with the movement number and the test results. In vintage watches an original certificate (“bulletin de marche”) that matches the movement adds value and helps prove originality. Today many brands only record certification in their own warranty card.

Also called: bulletin de marche, rate certificate, COSC certificate

See also: COSC, Chronometer, Box and papers, Warranty card, Full set

Brands: Ferdinand Berthoud, Ball Watch, Formex

Guide: Real or fake?

Co-Axial escapementMovement

Co-Axial is Omega's name for the escapement invented by English watchmaker George Daniels and put into series production by Omega in 1999. It reduces sliding friction between the parts, aiming for longer stable running and longer service intervals. It is found in most current Omega mechanical watches and is serviced by Omega or trained watchmakers.

Also called: Co-Axial, coaxial escapement, Daniels escapement

See also: Escapement, Lever escapement, Master Chronometer, Service interval

Brands: Omega

Guide: Swiss watch brands A–Z

Column wheelMovement

The column wheel is a small castellated wheel that controls the start, stop and reset functions of a chronograph. It is harder to make and adjust than a cam system and gives a smoother, more precise pusher feel. Collectors value column-wheel chronographs, and you can often spot the wheel through a display caseback.

Also called: column-wheel chronograph, castle wheel

See also: Chronograph, Cam-actuated chronograph, Vertical clutch, Horizontal clutch

Brands: Fortis, Hublot, Longines, Omega, Roger Dubuis, Zenith

Guide: How much is my watch worth?

Compass bezelInstruments and scales

A rotating bezel marked with cardinal directions that lets you use a watch as a simple compass with the sun: point the hour hand at the sun and the south (in the northern hemisphere) lies halfway between it and 12 o’clock. Some field and expedition watches use it. It is a practical aid and not a magnetic compass.

Also called: sun compass, compass ring, directional bezel

See also: Rotating bezel, Bidirectional bezel, Field watch, Tool watch

Guide: How much is my watch worth?

Complete calendarComplications

A calendar showing day, date and month, almost always with a moon phase, but which does not know the length of each month: the date must be advanced by hand after months with fewer than 31 days. Known in French as “quantième complet”, it was a popular complication of the 1940s and 1950s and is a classic of vintage collecting.

Also called: full calendar, quantième complet, triple calendar moon phase

See also: Triple calendar, Moon phase, Annual calendar, Perpetual calendar

Brands: Angelus, Girard-Perregaux, Universal Genève, Zenith

Guide: How much is my watch worth?

ComplicationComplications

Any function of a watch beyond showing hours, minutes and seconds, such as a chronograph, calendar, moon phase or minute repeater. Each complication adds parts and assembly work to the movement, which usually raises the price and the cost of servicing. Rare or difficult complications, and well-preserved examples of them, are a major driver of value at auction.

Also called: horological complication

See also: Grand complication, Chronograph, Perpetual calendar, Minute repeater, Tourbillon

Guide: How much is my watch worth?

Constant force mechanismComplications

A device that delivers the same amount of energy to the escapement whether the mainspring is fully wound or almost unwound, which improves precision over the whole power reserve. Common solutions are remontoires and the fusee and chain. It is a sign of high technical ambition and appears mainly in expensive watches.

Also called: constant-force escapement, force constante

See also: Remontoire, Fusee and chain, Isochronism, Escapement

Brands: Girard-Perregaux

Guide: Most valuable Swiss watches

COSCPrecision and certificates

The Contrôle Officiel Suisse des Chronomètres, the official Swiss chronometer testing institute, founded in 1973. It tests uncased movements for 15 days in five positions and at three temperatures; to pass, the mean daily rate must be within −4 and +6 seconds. Most chronometers from Rolex, Omega, Breitling and others are COSC certified.

Also called: Contrôle Officiel Suisse des Chronomètres, Swiss chronometer test

See also: Chronometer, Chronometer certificate, METAS, Superlative Chronometer, Accuracy

Brands: Ferdinand Berthoud, Ball Watch, Breitling, Formex, Mido, Perrelet

Guide: How much is my watch worth?

Côtes de GenèveMovement

Côtes de Genève is a decoration of parallel, wave-like stripes applied to bridges and rotors with a rotating tool. It is the most recognisable movement decoration of Swiss watchmaking and is visible through display casebacks. Even, crisp stripes indicate careful work, while blurred or uneven striping suggests cheaper finishing.

Also called: Geneva stripes, Geneva waves, Cotes de Geneve

See also: Movement finishing, Perlage, Anglage, Bridge

Count-up bezelCase

A count-up bezel carries a 60-minute scale running clockwise, with the zero marker (often a triangle or luminous pip) at the top. You align the zero with the minute hand at the start and read the elapsed time directly against the hand. It is the classic dive-watch bezel, usually combined with a unidirectional mechanism.

Also called: elapsed-time bezel, dive bezel, diver's bezel

See also: Unidirectional bezel, Countdown bezel, Dive watch, Lume plot

Brands: Zodiac

Countdown bezelCase

A countdown bezel has numerals that run backwards, so you can set the remaining time and read how many minutes are left until an event, such as a parking meter expiring or a regatta start. It is the reverse of the count-up dive bezel. Countdown bezels are found on some pilot, racing and sailing watches.

Also called: count-down bezel, reverse bezel

See also: Count-up bezel, Rotating bezel, Countdown timer, Regatta timer

Countdown timerInstruments and scales

A function or scale that shows the time remaining until a set moment, for example before a race starts or a parking meter runs out. On mechanical watches it is usually a rotating bezel with a reversed scale or a dedicated countdown complication. Regatta watches use a special version with a 5- or 10-minute countdown.

Also called: count-down timer, countdown, timer

See also: Countdown bezel, Regatta timer, Rotating bezel, Chronograph

Brands: Aquastar

Guide: How much is my watch worth?

Counterfeit watchMarket and collecting

A fake watch that illegally uses another brand's name, logo or protected design and is passed off as genuine. Counterfeits are often sold at a "bargain" price or with forged papers. Warning signs include poor printing on the dial, wrong fonts, a movement that doesn't match the reference and inconsistent serial numbers; in case of doubt, have the watch authenticated before buying.

Also called: fake watch, fake, knock-off, counterfeit

See also: Replica watch, Authentication, Franken watch, Serial number, Homage watch

Brands: Glycine, Adriatica, Aerowatch, Akrivia / Rexhep Rexhepi, Alpina, Andersen Genève, Andreas Strehler, Angelus

Guide: Real or fake?

CrownCase

The crown is the knurled button on the side of the case, normally at 3 o'clock, used to wind the mainspring, set the time and, in many watches, the date. It is attached to the winding stem. An original crown often bears the brand's logo. A missing logo, wrong size or non-matching crown is a common sign of a replacement part.

Also called: winding crown, winder

See also: Screw-down crown, Winding stem, Crown guard, Keyless works, Aftermarket parts

Guide: Real or fake?

Crown guardCase

Crown guards are shoulders on the case on either side of the crown that protect it from knocks, which could bend the winding stem. They are typical of dive and tool watches. Their shape changed over production years in some models, so collectors use them to date a case and check it is correct for the reference.

Also called: crown guards, crown protector, crown shoulders

See also: Crown, Screw-down crown, Dive watch, Tool watch

Brands: Breguet

CrystalCase

The crystal is the transparent cover over the dial. Watchmakers call it a crystal even though it may be made of sapphire, mineral glass or acrylic. The material, shape and any magnifier are typical of a model and era, so a correct crystal matters for originality. Scratches and chips are cosmetic, but cracks can let in moisture.

Also called: watch glass, glass

See also: Sapphire crystal, Mineral crystal, Acrylic crystal, Crystal replacement, Cyclops lens

Guide: Watch condition

Crystal replacementService and water resistance

Fitting a new watch glass when the old one is scratched, chipped or cracked. Ideally the replacement matches the original type – acrylic, mineral or sapphire – and its shape. On vintage watches, an original crystal with signed details may matter to collectors, so keep the original if replaced; afterwards the watch should be pressure-tested.

Also called: glass replacement, new crystal

See also: Crystal, Sapphire crystal, Acrylic crystal, Pressure test, Parts replacement

Guide: Watch condition

Cushion caseCase

A cushion case has a square or rectangular outline with rounded sides and corners, resembling a cushion. The shape appeared in early wristwatches of the 20th century and is still used on dress and dive watches today. Cushion cases tend to wear larger on the wrist than a round watch with the same nominal diameter.

Also called: coussin case, cushion-shaped case

See also: Case, Tonneau case, Case diameter, Dress watch

Brands: JeanRichard, Laurent Ferrier

Cyclops lensCase

A cyclops lens is a small magnifying bubble on the crystal over the date window, making the date easier to read. It is a well-known feature of Rolex date models and has been copied widely. On genuine Rolex watches the magnification is strong, so the date nearly fills the lens; a weak magnification or a misaligned lens is a classic warning sign of a fake.

Also called: cyclops, date magnifier, magnifier lens

See also: Date window, Crystal, Counterfeit watch, Replica watch

Guide: Real or fake?

D

Date windowDial and hands

A date window is an opening in the dial through which a rotating date disc shows the day of the month. It is usually at 3 o'clock, sometimes at 6 or elsewhere. The font, alignment and colour of the date disc help confirm originality. Correcting the date should be avoided in the hours around midnight on many mechanical watches.

Also called: date aperture, date

See also: Cyclops lens, Big date, Day-date display, Complete calendar

Dauphine handsDial and hands

Dauphine hands are tapered, pointed hands with a faceted surface split by a central ridge, so each half reflects light differently. They are a classic style of mid-20th-century dress watches and remain popular today. Well-cut facets show quality. They often carry little or no luminous material.

Also called: dauphine

See also: Baton hands, Leaf hands, Dress watch, Alpha hands

Day-date displayDial and hands

A day-date display shows both the day of the week and the date, usually in windows on the dial; the day may also appear in an arc at 12 o'clock or on a subdial. It is a simple calendar function and must be corrected at the end of shorter months. Some watches offer the day in several languages, which can identify the market a watch was sold in.

Also called: day-date, day and date

See also: Date window, Complete calendar, Triple calendar, Annual calendar

Brands: Rolex

Day-night indicatorComplications

A small display, often a rotating disc with sun and moon or a light-and-dark half, that shows whether the time displayed is day or night. It helps when setting a calendar watch, since date changes should not be made at certain hours, and when reading a second time zone in 12-hour format.

Also called: day/night indicator, jour/nuit, day and night display

See also: AM/PM indicator, Dual time, GMT, World timer

Brands: Andersen Genève

Guide: How much is my watch worth?

Dead-beat secondsComplications

A mechanism that makes the seconds hand of a mechanical watch jump once per second, like a quartz watch, instead of sweeping in small steps. It was originally intended for precise timing, for instance by doctors, and is now made by a small number of high-end brands. A mechanical watch with jumping seconds should therefore not be mistaken for a quartz watch.

Also called: seconde morte, jumping seconds, true beat, deadbeat seconds

See also: Constant force mechanism, Remontoire, Small seconds, Quartz watch

Brands: Arnold & Son, F.P. Journe

Guide: Most valuable Swiss watches

Decimal scaleComplications

A chronograph scale that divides the minute into 100 units instead of 60 seconds, so timings can be written down as decimal fractions of a minute. It was used for industrial time-and-motion studies and some sports. Decimal-scale chronographs are a niche among vintage pieces and are mostly of interest to specialist collectors.

Also called: decimal minute scale, 1/100 minute scale

See also: Chronograph, Tachymeter, Pulsometer, Telemeter

Guide: Most valuable Swiss watches

Decompression scaleInstruments and scales

A table or scale on the dial or bezel of some diving watches that indicates the time a diver may stay at a certain depth without decompression stops. It was common in the 1960s and 1970s, for example on the Doxa SUB. Today dive computers have taken over this role, so it is mainly of historical and collector interest.

Also called: no-decompression scale, no-deco bezel, decompression table

See also: Dive watch, Depth gauge, Unidirectional bezel, ISO 6425

Guide: Most valuable Swiss watches

DemagnetisationService and water resistance

Removal of magnetism from a watch movement using a demagnetiser. A magnetised hairspring can stick its coils together, making a mechanical watch run very fast or erratically. It is a quick, inexpensive job and is often the first thing a watchmaker checks when a watch suddenly gains minutes per day.

Also called: demagnetization, degaussing, demagnetising

See also: Magnetism, Antimagnetic, Hairspring, Accuracy, Gauss

Guide: Watch condition

Deployant claspStraps and bracelets

A deployant clasp is a folding buckle used on leather or rubber straps: the strap stays closed in a loop and a hinged metal mechanism unfolds to put the watch on. It reduces wear on the strap and the risk of dropping the watch. Most designs have push-buttons to open. Original signed deployant clasps from luxury brands are often sold separately and can be fairly valuable.

Also called: deployment clasp, deployant buckle, boucle déployante

See also: Folding clasp, Tang buckle, Leather strap, Rubber strap

Depth gaugeInstruments and scales

A mechanical device in some dive watches that shows the current depth, usually with a hand driven by water pressure, often with a maximum-depth memory. Examples include the Blancpain X Fathoms and the IWC Aquatimer Deep series. Proper function and calibration should be checked when buying, as repairs are specialised.

Also called: depth meter, bathymeter, profondimètre

See also: Dive watch, Decompression scale, Water resistance, ISO 6425

Brands: Aquastar, Oris

Guide: Most valuable Swiss watches

Desk diverTypes of watch

"Desk diver" is a tongue-in-cheek term for a dive watch that is worn in the office and never goes underwater. The phrase reflects the fact that most dive watches are bought for their looks and robustness rather than for diving. It has no technical meaning, but sellers sometimes use it to say a watch shows little wear and has not been exposed to salt water.

Also called: desk diver watch, mall diver

See also: Dive watch, Tool watch, Sports watch, Water resistance

Detent escapementMovement

The detent escapement, also called the chronometer escapement, impulses the balance directly and only in one direction, with very little friction. It was used in marine chronometers and some high-grade pocket watches. It is precise but sensitive to shocks, so it is rare in wristwatches and a mark of specialist watchmaking.

Also called: chronometer escapement, spring detent

See also: Escapement, Lever escapement, Observatory chronometer, Pocket watch

Guide: Most valuable Swiss watches

DialDial and hands

The dial is the face of the watch: the plate with markers, numerals, logo and inscriptions over which the hands move. It is the most visible part and has the greatest effect on value. Collectors look for original dials in good condition with correct printing; refinished or replaced dials can cut the value of a vintage watch dramatically.

Also called: face, watch face, cadran

See also: Redial, Service dial, Applied indices, Subdial, Patina

Guide: How much is my watch worth?

Display casebackCase

A display caseback has a window, usually sapphire, through which the movement can be seen. It lets owners admire the finishing, the balance and the rotor. Many traditional sports models and vintage watches have solid backs, so a display back on such a model may mean a modification, or simply a different reference.

Also called: exhibition caseback, see-through caseback, sapphire caseback, glass back

See also: Caseback, Movement finishing, Sapphire crystal, Franken watch

Brands: Chronoswiss, Adriatica, Blancpain, Jaquet Droz, Laurent Ferrier, Maurice de Mauriac

Dive watchTypes of watch

A dive watch is built for underwater use: high water resistance, a screw-down crown, a unidirectional rotating bezel for timing dives and highly legible luminous hands and markers. The international standard ISO 6425 sets the requirements for a true diver's watch, including at least 100 m water resistance. Classic Swiss examples include the Rolex Submariner and Blancpain Fifty Fathoms. Water resistance should be re-tested after any service.

Also called: diver's watch, diving watch, diver watch

See also: ISO 6425, Unidirectional bezel, Screw-down crown, Water resistance, Desk diver

Brands: Favre Leuba, Aquastar, Blancpain, Ollech & Wajs, Rolex, Certina, Doxa, Eberhard & Co.

Guide: How much is my watch worth?

Diver extensionStraps and bracelets

A diver extension is a fold-out link hidden in the clasp of a dive-watch bracelet, which lengthens the bracelet enough to fit over a wetsuit sleeve. It is usually a few centimetres long and is opened by flipping it out from under the clasp. Rolex calls its version Fliplock; Glidelock is a different, sliding system. A working extension is part of a dive watch's original equipment.

Also called: diver's extension, wetsuit extension, Fliplock

See also: Glidelock, Folding clasp, Dive watch, Micro-adjustment

DLC coatingMaterials

DLC (diamond-like carbon) is a very hard, thin carbon coating applied to steel or titanium, usually to give a black, scratch-resistant finish. It is generally tougher than standard PVD finishes and popular on tactical, dive and sports watches. Deep impacts can still chip it and expose the metal underneath. Re-coating requires stripping the whole part, so damage to a DLC case noticeably lowers condition grades.

Also called: DLC, diamond-like carbon, black DLC

See also: PVD coating, Titanium, Stainless steel, Tool watch

Guide: Watch condition

Domed crystalCase

A domed crystal is curved upwards instead of flat. It gives a vintage look and distorts the dial slightly when seen from the side, an effect many owners enjoy. Domed crystals can be acrylic or sapphire; domed sapphire is costly to make and often has an anti-reflective coating to reduce glare. The dome adds to the overall thickness of the watch.

Also called: dome crystal, bubble crystal

See also: Crystal, Box crystal, Acrylic crystal, Case thickness

Brands: Corum

Dress watchTypes of watch

A dress watch is an elegant, usually thin watch meant to be worn with formal clothes and to slip under a shirt cuff. Typical features are a precious-metal or polished case, a simple dial with few or no complications, slim hands and a leather strap. The Patek Philippe Calatrava is the classic example. Many dress watches have little water resistance and should be kept away from water.

Also called: formal watch, dress piece

See also: Calatrava, Leather strap, Case thickness, Manual winding, Tank watch

Guide: How much is my watch worth?

Dual timeComplications

A watch that displays two time zones at once, for example via a second hour hand, a subdial or a 24-hour hand. The term overlaps with GMT; dual-time watches often show the second zone in 12-hour format, so an AM/PM or day-night indicator is sometimes added to avoid confusion.

Also called: two time zones, second time zone, dual timezone

See also: GMT, World timer, Day-night indicator, AM/PM indicator

Brands: Laurent Ferrier, Armin Strom, Epos, Glycine, Greubel Forsey, Hautlence, Rolex, Tissot

Guide: How much is my watch worth?

E

E6BInstruments and scales

A flight computer, originally a circular slide rule used by pilots, for calculating wind correction, fuel consumption, ground speed and time. Some pilot watches integrate an E6B-style scale into the bezel and dial. The name refers to the instrument, not to a watch model, and is often used in descriptions of pilot chronographs.

Also called: E-6B, flight computer, whiz wheel

See also: Slide-rule bezel, Pilot watch, Rotating bezel, Tool watch

Guide: How much is my watch worth?

EasylinkStraps and bracelets

Easylink is Rolex's name for its comfort extension link built into the clasp of many Oyster bracelets. It allows the bracelet to be lengthened by about 5 mm without tools, for example on hot days when the wrist swells. It is a brand-specific feature; other brands offer similar quick-adjust systems under different names.

Also called: Rolex Easylink, Easylink comfort extension

See also: Glidelock, Micro-adjustment, Oyster bracelet, Folding clasp

Guide: Swiss watch brands A–Z

ÉbaucheMovement

An ébauche is an unfinished movement blank or kit, supplied by a specialist maker to watch brands that then assemble, finish, regulate and sometimes modify it. Many respected Swiss brands historically used ébauches from makers such as Valjoux or ETA. An ébauche-based watch is not inferior by definition; finishing and regulation decide the quality.

Also called: ebauche, movement blank, raw movement

See also: ETA, Manufacture, In-house movement, Valjoux 7750, Calibre

Brands: Biver

Guide: How much is my watch worth?

Electric watchTypes of movement

An electric watch uses a battery to drive a balance wheel electromagnetically, instead of a mainspring. The Hamilton Electric of 1957 is regarded as the first electric wristwatch. These watches were a short transitional phase before quartz and are of interest mainly to collectors; servicing them requires specialist knowledge and parts.

Also called: electromechanical watch, electric wristwatch

See also: Tuning fork watch, Quartz watch, Battery, Vintage

Guide: Most valuable Swiss watches

Enamel dialDial and hands

An enamel dial is made by fusing powdered glass onto a metal base in a kiln, creating a deep, glossy surface that does not fade. Enamel was standard on old pocket watches and is today a mark of high-end craftsmanship. It is fragile: hairline cracks and chips, especially around the dial feet and the centre hole, reduce value noticeably.

Also called: email dial, porcelain dial

See also: Grand feu enamel, Lacquer dial, Dial, Pocket watch

Brands: Akrivia / Rexhep Rexhepi, Charles Girardier, Speake-Marin, Hamilton, Jaquet Droz, Ulysse Nardin

Guide: Watch condition

End linksStraps and bracelets

End links are the pieces that connect a bracelet to the case between the lugs and fill the gap so that the bracelet sits flush. Each end link is shaped to fit a specific case, and on brands like Rolex it carries a number that should match the bracelet and the reference. Wrong or aftermarket end links are a common sign of a mismatched or assembled bracelet.

Also called: endlinks, end pieces, FEL

See also: Solid end links, Hollow links, Bracelet, Lug, Aftermarket parts

Guide: Real or fake?

Equation of timeComplications

A complication that shows the difference between mean time, which watches keep, and true solar time, which a sundial shows. Over the year this difference varies between roughly minus 16 and plus 14 minutes, and the watch displays it with a hand on a dedicated scale, driven by a cam that turns once a year. It is rare and usually found in high-end or astronomical watches.

Also called: équation du temps, EoT

See also: Astronomical complication, Perpetual calendar, Grand complication, Complication

Guide: Most valuable Swiss watches

Escape wheelMovement

The escape wheel is the last wheel of the going train. Its specially shaped teeth are alternately locked and released by the pallet fork, letting the train advance one step at a time. Modern escape wheels may be made of steel or silicon. Worn or damaged teeth lead to poor amplitude and timekeeping problems.

Also called: escapement wheel, scape wheel

See also: Escapement, Pallet fork, Going train, Lever escapement

Brands: Frederique Constant

EscapementMovement

The escapement releases the energy of the mainspring in small, regular steps and gives the balance a small impulse on each swing. It produces the familiar ticking sound. The lever escapement is the standard in wristwatches; alternatives include the co-axial and the detent escapement. Its condition strongly affects accuracy.

Also called: escapement mechanism

See also: Lever escapement, Escape wheel, Pallet fork, Balance wheel, Co-Axial escapement

Brands: Blancpain, Girard-Perregaux, Haldimann, Laurent Ferrier, Maurice Lacroix, Omega, Ulysse Nardin, Ateliers deMonaco

EstimateMarket and collecting

A price range given by an auction house or appraiser for what a watch is expected to achieve, for example 8,000–12,000. Auction estimates are partly set to attract bidders and do not include fees; results can fall below or far above them. An online estimate gives a quick orientation, whereas a written appraisal documents a value formally.

Also called: auction estimate, pre-sale estimate, valuation

See also: Hammer price, Watch appraisal, Buyer's premium, Investment watch

Guide: How much is my watch worth?

ETAMovement

ETA SA, based in Grenchen and part of the Swatch Group, is Switzerland's largest maker of watch movements. Its calibres, such as the 2824-2, 2892-A2 and Valjoux 7750, are found in watches of many brands. Since the 2000s ETA has reduced supplies to brands outside the group, which helped competitors such as Sellita grow.

Also called: ETA SA, ETA Manufacture Horlogère Suisse

See also: ETA 2824-2, Valjoux 7750, Sellita SW200, Ébauche, Swiss movement

Brands: Aerowatch, Hamilton, Adriatica, Atlantic, Auguste Reymond, Norqain, Rado, Tissot

Guide: Swiss watch brands A–Z

ETA 2824-2Movement

The ETA 2824-2 is a Swiss automatic movement with date, running at 28,800 vph, and one of the most widely used calibres ever. It powers countless watches from many brands, often renamed by them. It is reliable and easy to service. ETA has offered it in several grades with different finishing and regulation.

Also called: 2824, ETA 2824, 2824-2

See also: ETA, Sellita SW200, ETA 2892-A2, Calibre, Ébauche

Brands: Auguste Reymond, Eberhard & Co., Ollech & Wajs, Tissot, Norqain, Zodiac

Guide: How much is my watch worth?

ETA 2892-A2Movement

The ETA 2892-A2 is a thin, high-quality Swiss automatic movement at 28,800 vph. Its flat construction makes it a common base for modules such as chronographs, GMT or calendars, and several brands use modified versions under their own calibre names. It is generally regarded as a step above the ETA 2824.

Also called: 2892, ETA 2892, 2892-A2

See also: ETA, ETA 2824-2, Calibre, Ébauche

Brands: Emile Chouriet

Guide: How much is my watch worth?

Everose goldMaterials

Everose is Rolex's name for its own 18k rose gold alloy, cast in the company's foundry. It contains a small amount of platinum, which Rolex says keeps the pink colour from fading over time. The term appears on Rolex catalogues and papers for full rose gold models and for "Everose Rolesor" two-tone pieces. It is a brand-specific name; other makers have their own rose gold alloys.

Also called: Rolex Everose, Everose Rolesor

See also: Rose gold, 18k gold, Two-tone, Oystersteel, Gold

Guide: Swiss watch brands A–Z

Extract from the ArchivesMarket and collecting

A document issued by a manufacturer from its historical records, confirming details such as the movement and case numbers, production date, original materials and sometimes the date of sale or destination country. Patek Philippe's Extract from the Archives is the best-known example; several other houses offer similar certificates. It does not authenticate the watch's current condition or parts, but confirms how it left the factory.

Also called: archive extract, archive certificate, certificate of origin

See also: Provenance, Serial number, Authentication, Vintage

Brands: Omega, Longines, Patek Philippe

Guide: Real or fake?

F

Faraday cage casePrecision and certificates

A soft-iron inner case around the movement that diverts magnetic fields so they do not reach the balance and hairspring. It is used in antimagnetic watches such as the IWC Ingenieur and the Rolex Milgauss. The inner case makes the watch thicker and hides the movement, so these watches have no display back.

Also called: soft-iron inner case, soft iron cage, antimagnetic inner case

See also: Antimagnetic, Gauss, Magnetism, Case

Guide: How much is my watch worth?

FauxtinaDial and hands

Fauxtina, a blend of faux and patina, is modern luminous material tinted to look like aged vintage lume. Many brands use it on heritage re-editions to evoke an old look. It is not a fault, but it is no indicator of age either. Fauxtina in a vintage watch can mean the hands or dial have been replaced or relumed, so check carefully.

Also called: faux patina, vintage lume, aged-look lume

See also: Patina lume, Super-LumiNova, Relume, Lume

Guide: Real or fake?

Field watchTypes of watch

A field watch is a simple, robust military-style watch for soldiers: a clear black dial with Arabic numerals, often a 24-hour inner track, luminous hands and a plain steel or matte case on a fabric or leather strap. The type goes back to watches issued in the two World Wars. Today it stands for an affordable, legible everyday watch. Genuine issued pieces with markings are of interest to collectors.

Also called: military field watch, infantry watch, A-11 style watch

See also: Military watch, Tool watch, NATO strap, Arabic numerals, Pilot watch

Brands: Formex, Luminox

Flieger watchTypes of watch

"Flieger" is German for aviator; a Flieger watch follows the design of German WWII pilot watches: a black dial with large white Arabic numerals, a triangle with two dots at twelve, sword hands and a large onion crown. The term is used for both the historic B-Uhren and modern watches in this style. Original wartime pieces are rare and often faked or assembled from parts.

Also called: Fliegeruhr, flieger, German pilot watch

See also: B-Uhr, Pilot watch, Military watch, Sword hands, Bund strap

Guide: Real or fake?

Flyback chronographComplications

A chronograph that can be reset and restarted with a single press of the reset pusher while it is running, without stopping it first. It was developed for pilots and navigators who needed to time consecutive legs quickly. The French term “retour en vol” is often seen on dials and in catalogues.

Also called: retour en vol, fly-back

See also: Chronograph, Rattrapante (split-seconds chronograph), Pilot watch, Column wheel

Brands: Frederique Constant, Alpina, Ateliers deMonaco, H. Moser & Cie., Hublot, Richard Mille, Roger Dubuis

Guide: How much is my watch worth?

Flying tourbillonComplications

A tourbillon whose cage is supported from below only, with no bridge on top, so it seems to float in its dial opening. The design was developed in Glashütte by Alfred Helwig. It gives an unobstructed view of the rotating cage but is harder to make stable, and it is found mainly in high-end watches.

Also called: tourbillon volant, cantilevered tourbillon

See also: Tourbillon, Multi-axis tourbillon, Carrousel, Bridge

Brands: Charles Girardier, Czapek & Cie, Roger Dubuis, Gerald Charles, Haldimann

Guide: Most valuable Swiss watches

Folded linksStraps and bracelets

Folded links are made by folding a strip of sheet metal into the shape of a link, so that the fold or seam is visible from the side or back. They were common on vintage bracelets from the 1950s to the 1970s and are light but prone to stretching. Original folded-link bracelets in good condition are valued on vintage sports watches, as they are period-correct.

Also called: folded link bracelet

See also: Hollow links, Solid end links, Bracelet stretch, Vintage

Guide: Watch condition

Folding claspStraps and bracelets

A folding clasp is the hinged metal closure typical of metal bracelets: one or more blades fold over each other and lock with a cover or push-buttons. Safety clasps add an extra lock, and many dive clasps include an extension. The clasp usually carries the brand's logo and on some brands a production code that helps to date the bracelet. A loose or weak clasp is a safety risk.

Also called: fold-over clasp, safety clasp, butterfly clasp

See also: Deployant clasp, Bracelet, Diver extension, Micro-adjustment, Glidelock

Forged carbonMaterials

Forged carbon is made by pressing short, chopped carbon fibres with resin under heat and pressure, which produces an irregular marbled pattern instead of the regular weave of classic carbon fibre. No two cases look exactly alike. Audemars Piguet popularised it in watchmaking on the Royal Oak Offshore; several other brands now use similar materials under their own names. It is light and strong but cannot be polished or refinished.

Also called: forged carbon fibre, chopped carbon

See also: Carbon fibre, Ceramic, Luxury sports watch, Sports watch

Franken watchMarket and collecting

A watch assembled from parts of different watches, references or even brands, and sold as if original. Typical signs are a dial, movement, hands or case that do not belong together, or wrong-period parts. Even if each component is genuine, a franken watch is worth much less than an original, so experts compare every part against the reference.

Also called: frankenwatch, frankenstein watch, franken

See also: Aftermarket parts, Redial, Service dial, Authentication, Counterfeit watch

Guide: Real or fake?

Free-sprung balanceMovement

A free-sprung balance has no regulator index on the hairspring. Instead, the rate is adjusted by turning small weights or screws on the balance rim. This avoids disturbing the hairspring and is considered more stable. Rolex, Patek Philippe and Omega use free-sprung designs in many of their movements.

Also called: free sprung, variable inertia balance

See also: Balance wheel, Hairspring, Regulator, Index regulator, Regulation

Brands: Simon Brette

FrequencyMovement

Frequency is how fast the balance of a mechanical watch oscillates, given in hertz (Hz) or vibrations per hour. Common values are 3 Hz (21,600 vph) and 4 Hz (28,800 vph); some movements, such as Zenith's El Primero, run at 5 Hz (36,000 vph). Higher frequency gives a smoother seconds hand and can improve stability, but uses more energy.

Also called: Hz, beat frequency, balance frequency

See also: Vibrations per hour, Beat rate, Balance wheel, Power reserve

Brands: Breitling, Girard-Perregaux

Full setMarket and collecting

A watch offered with everything it originally came with: box, outer box, warranty card or certificate, manuals, hang tags and sometimes extra links or the purchase receipt. The papers should match the watch's serial number. A complete, matching set makes a watch easier to sell and typically achieves a higher price than the watch alone, especially for sought-after modern and neo-vintage models.

Also called: complete set, full kit, fullset

See also: Box and papers, Warranty card, Full-set premium, Serial number

Guide: Sell a luxury watch

Full-set premiumMarket and collecting

The additional amount buyers pay for a watch with its original box and matching papers compared with the same watch sold alone. The premium varies by brand, model and age and is often largest for sought-after modern and neo-vintage models. Original papers for vintage watches are rare, so their presence can make a noticeable difference.

Also called: box and papers premium, B&P premium

See also: Full set, Box and papers, Warranty card, Retail price

Guide: How much is my watch worth?

Fusee and chainComplications

A cone-shaped pulley connected to the barrel by a tiny chain, which compensates for the falling force of the mainspring as it unwinds. Fully wound, the chain pulls on the narrow end of the cone; nearly unwound, on the wide end. Common in old pocket watches and marine chronometers, it is rare in wristwatches and found mainly at A. Lange & Söhne and a few other high-end makers.

Also called: fusée, fusee chain, fusee

See also: Constant force mechanism, Remontoire, Barrel, Mainspring

Brands: Ferdinand Berthoud

Guide: Most valuable Swiss watches

G

GasketCase

Gaskets are seals, usually rubber or synthetic rings, placed at the crystal, caseback, crown and pushers to keep water and dust out. They age, dry out and lose elasticity over the years, even if the watch is not worn. That is why water resistance is never guaranteed on an older watch until the gaskets have been replaced and the case pressure-tested.

Also called: seal, O-ring, joint

See also: Water resistance, Gasket replacement, Pressure test, Screw-down crown, Screw-down caseback

Guide: Watch condition

Gasket replacementService and water resistance

The replacement of the rubber or synthetic seals at the caseback, crown, pushers and crystal that keep water and dust out. Gaskets age, dry out and lose their elasticity, so they are usually replaced with every service or whenever the case is opened. A pressure test afterwards confirms that the watch is water-resistant again.

Also called: seal replacement, new gaskets, reseal

See also: Gasket, Pressure test, Water resistance, Service

Guide: Watch condition

GaussPrecision and certificates

A unit of magnetic flux density used to state how strongly a watch resists magnetic fields. The Rolex Milgauss takes its name from its resistance of 1,000 gauss, while Omega’s METAS-certified Master Chronometers withstand 15,000 gauss. For comparison, the basic ISO 764 standard corresponds to about 60 gauss.

Also called: G, gauss rating

See also: Antimagnetic, Magnetism, METAS, Faraday cage case

Guide: Watch condition

Gear trainMovement

Gear train is the general term for interlocking wheels and pinions that transmit motion inside a watch. In everyday use it usually means the going train from barrel to escapement, but separate gear trains also drive the hands, the date or a chronograph. Clean, well-lubricated trains are essential for good timekeeping.

Also called: wheel train, train

See also: Going train, Barrel, Escapement, Lubrication

Brands: Arnold & Son

Geneva SealPrecision and certificates

A quality hallmark (Poinçon de Genève) founded in 1886 for watches made in the canton of Geneva. It sets strict rules for the finishing of movement parts and, in its current form, also tests the finished watch. The seal is engraved on the movement and sometimes the case; Vacheron Constantin and Roger Dubuis are among the best-known brands using it.

Also called: Poinçon de Genève, Geneva Hallmark, Geneva Stamp

See also: Qualité Fleurier, Movement finishing, Côtes de Genève, Anglage, Chronometer

Brands: Roger Dubuis, Ateliers deMonaco, Vacheron Constantin, Patek Philippe, Baume & Mercier, Chopard

Guide: How much is my watch worth?

Ghost bezelDial and hands

A ghost bezel is an old aluminium bezel insert whose colours have faded strongly, often to a pale grey, light blue or pink, through years of sun and seawater. It is a collectors' nickname. Natural, even fading can make a vintage watch more desirable; artificially bleached inserts exist, so provenance and consistency with the rest of the watch matter.

Also called: faded bezel, faded insert, ghost insert

See also: Bezel, Patina, Ceramic bezel insert, Tropical dial

Guide: Most valuable Swiss watches

Gilt dialDial and hands

A gilt dial has text and markers in gold-coloured print or metal, typically on a glossy black background. On many sports watches of the 1950s and 1960s the gold text was created by a galvanic process, leaving the brass base visible through the black lacquer. Original gilt dials in good condition are highly prized by vintage collectors.

Also called: gilt, gold print dial, gilt print

See also: Gloss dial, Dial, Vintage, Redial

Guide: Most valuable Swiss watches

GlidelockStraps and bracelets

Glidelock is Rolex's name for its tool-free extension system in the clasp of certain dive watches such as the Submariner and Deepsea. A notched rail under the clasp lets the bracelet be lengthened by up to about 20 mm in small steps, so the watch can be worn over a wetsuit or adjusted for comfort. It is a brand-specific feature and a useful detail when checking a Rolex bracelet.

Also called: Rolex Glidelock, Glidelock clasp

See also: Diver extension, Easylink, Micro-adjustment, Folding clasp, Oyster bracelet

Guide: Swiss watch brands A–Z

Gloss dialDial and hands

A gloss dial has a shiny, reflective lacquered surface. Glossy black dials are typical of vintage sports watches with gilt printing and of many modern luxury pieces with white printing. Gloss surfaces show scratches, spotting and cracking clearly, so condition is easy to assess. Correct gloss and printing help separate an original from a redial.

Also called: glossy dial, high-gloss dial

See also: Matte dial, Gilt dial, Lacquer dial, Redial

GlucydurMovement

Glucydur is a beryllium-copper alloy used for balance wheels. It is hard, non-magnetic, resistant to deformation and changes little with temperature, which makes it well suited for precision balances paired with a modern hairspring. 'Glucydur balance' in a specification indicates a good-quality regulating organ.

Also called: Glucydur balance, beryllium bronze balance

See also: Balance wheel, Hairspring, Nivarox, Free-sprung balance

GMTComplications

A function that shows a second time zone, usually with an extra 24-hour hand read against a 24-hour bezel or dial ring. The name comes from Greenwich Mean Time. With a rotating bezel, many GMT watches can show a third zone. On some models the local hour hand can be set independently, which travellers value highly.

Also called: GMT function, second time zone

See also: GMT watch, 24-hour bezel, Dual time, World timer, AM/PM indicator

Brands: Zodiac, Greubel Forsey, Cyrus Genève, Formex, Mauron Musy, Schwarz Etienne, Armand Nicolet, De Bethune

Guide: How much is my watch worth?

GMT watchTypes of watch

A GMT watch shows a second time zone with an extra hour hand that rotates once every 24 hours, read against a 24-hour bezel or dial ring. Many models allow the main hour hand to be set independently for travel. The Rolex GMT-Master, made for airline pilots in the 1950s, popularised the type; bezel colour combinations have well-known nicknames. Value depends heavily on reference, bezel and originality.

Also called: GMT, dual time watch, travel watch

See also: GMT, 24-hour bezel, Dual time, World timer, Pilot watch

Brands: Zodiac, Cyrus Genève, Formex, Greubel Forsey, Mauron Musy, Schwarz Etienne, Armand Nicolet, De Bethune

Guide: How much is my watch worth?

Going trainMovement

The going train is the series of wheels that carries power from the barrel to the escapement: typically centre, third, fourth and escape wheel. Its gear ratios turn the slow unwinding of the mainspring into the movement of the hands. Worn pivots in the going train cause a watch to lose amplitude and accuracy.

Also called: train, wheel train

See also: Gear train, Barrel, Escapement, Escape wheel

GoldMaterials

Gold is the classic precious metal for watch cases, bracelets and dial details. Swiss watches almost always use 18-carat gold (75 % pure, stamped 750), alloyed with other metals to set colour and hardness; older and American pieces may be 14k or lower. A genuine gold case carries fineness and hallmark stamps. Gold content gives a floor value, but collectible models are worth far more than their melt weight, so never judge a gold watch by weight alone.

Also called: solid gold, Au

See also: 18k gold, Yellow gold, White gold, Rose gold, Precious metal hallmark

Guide: How much is my watch worth?

Gold chatonsMovement

Gold chatons are gold settings into which jewels are pressed and then screwed to the plate. They were used to make jewels easy to replace and are now mainly decorative, seen in vintage pocket watches and some high-end modern movements. Their presence is a mark of traditional, elaborate watchmaking.

Also called: chatons, gold jewel settings, screwed chatons

See also: Jewels, Jewel bearing, Movement finishing, Pocket watch

Brands: Simon Brette

Guide: Most valuable Swiss watches

Gold-filledMaterials

Gold-filled refers to a case made by mechanically bonding a much thicker sheet of gold to a base-metal core, typically brass. It lasts far longer than electroplating and was very common on American and some Swiss watches in the first half of the 20th century, often stamped "10K GF", "Gold Filled" or with a guarantee such as "20 years". It is not solid gold and has only modest metal value.

Also called: GF, rolled gold, rolled gold plate, RGP, laminated gold

See also: Gold-plated, Gold, Yellow gold, Pocket watch, Precious metal hallmark

Brands: Hamilton

Guide: How much is my watch worth?

Gold-platedMaterials

Gold-plated means a base-metal case or bracelet (brass or steel) covered with a very thin layer of gold, usually applied by electroplating. It looks like solid gold when new, but the layer wears through at edges, lugs and the clasp, revealing the darker metal underneath. Markings such as "plaqué", "G.P." or microns of gold indicate plating. Plated watches have little metal value and are not worth replating for most models.

Also called: gold plate, GP, plaqué or, electroplated gold, gold electroplate

See also: Gold-filled, PVD coating, Gold, 18k gold, Two-tone

Brands: Adriatica, Raymond Weil, Universal Genève, Concord, Girard-Perregaux, Omega, Roamer

Guide: How much is my watch worth?

Grade 5 titaniumMaterials

Grade 5 titanium is an alloy of titanium with about 6 % aluminium and 4 % vanadium (Ti-6Al-4V). It is considerably harder than pure grade 2 titanium, so it resists scratches better and can be given a polished finish close to steel. Many high-end sports watches use it for cases and bracelets. The grade is usually stated in the specifications; visually it is hard to tell the two grades apart.

Also called: Ti-6Al-4V, titanium grade 5, Ti64

See also: Titanium, Stainless steel, Tantalum, Sports watch

Brands: Richard Mille

Grand complicationComplications

A watch that combines several major complications, traditionally at least one chiming function, one calendar or astronomical function and a chronograph. The term is not standardised, and some brands use it more loosely. True grand complications are made in very small numbers and belong to the most valuable watches at auction.

Also called: grande complication, supercomplication

See also: Complication, Minute repeater, Perpetual calendar, Rattrapante (split-seconds chronograph), Astronomical complication

Brands: Patek Philippe, Audemars Piguet, Blancpain, Greubel Forsey, IWC Schaffhausen, Jaeger-LeCoultre, Vacheron Constantin

Guide: Most valuable Swiss watches

Grand feu enamelDial and hands

Grand feu (great fire) enamel is enamel fired several times at very high temperatures, giving an especially deep, durable and colour-fast finish. Each firing carries the risk of bubbles or cracks, so many dials are rejected, which makes them costly. Grand feu dials are offered by top manufactures and are valued for their timeless look.

Also called: grand-feu, grand feu enamel dial, fired enamel

See also: Enamel dial, Lacquer dial, Dial, Dress watch

Brands: Charles Girardier, Akrivia / Rexhep Rexhepi, Andersen Genève, Jaquet Droz, Speake-Marin

Guide: Most valuable Swiss watches

Grande sonnerieComplications

A striking watch that chimes automatically, like a clock: every quarter hour it strikes the quarter and repeats the hour. Most also have a repeater function on demand and a selector to switch to petite sonnerie or silence. It needs its own power supply and many extra parts, making it one of the rarest and most expensive complications.

Also called: grand strike, grande sonnerie au passage

See also: Petite sonnerie, Minute repeater, Grand complication, Complication

Brands: Daniel Roth, Gérald Genta, F.P. Journe

Guide: Most valuable Swiss watches

Grey marketMarket and collecting

The sale of genuine, new or unworn watches outside the brand's authorised dealer network, for example by independent dealers who buy surplus stock. Grey-market watches are not fakes; they can be cheaper than retail for less popular models or more expensive for hyped ones. Warranty terms may differ from a purchase at an authorised dealer, so the papers and dates should be checked.

Also called: grey dealer, gray market, parallel market

See also: Authorised dealer (AD), Retail price, Unworn, Hype watch, Warranty card

Guide: Sell a luxury watch

Guilloché dialDial and hands

A guilloché dial is decorated with precise, repeating engraved patterns such as waves, basket weave or a barleycorn motif. True guilloché is cut by hand-operated rose-engine or straight-line engines; cheaper dials imitate the pattern by stamping. Hand-engraved guilloché is a sign of high craftsmanship and is found on fine dress watches and traditional brands.

Also called: guilloche dial, engine-turned dial, guilloché

See also: Dial, Enamel dial, Dress watch, Sunburst dial

Brands: Daniel Roth, Kari Voutilainen, Breguet, Chronoswiss, Philippe Dufour, Andersen Genève, Louis Erard, Rudis Sylva

H

Hacking secondsMovement

Hacking seconds means the seconds hand stops when the crown is pulled out to set the time, so the watch can be synchronised to the second. It was demanded for military use and is now standard in most modern mechanical movements. Many older calibres lack it, which is normal and not a defect.

Also called: hack, stop-seconds, seconds stop, hacking

See also: Stop-seconds, Setting lever, Keyless works, Military watch

HairspringMovement

The hairspring is the very fine spiral spring attached to the balance wheel that makes it swing back at a regular rate. It is the most delicate and important part of the timekeeping system. Magnetism, shocks or poor handling can deform it. Modern hairsprings are made of alloys such as Nivarox or of silicon.

Also called: balance spring, spiral, spring

See also: Balance wheel, Nivarox, Silicon hairspring, Breguet overcoil, Magnetism

Brands: Arnold & Son, Breguet, Bovet, Mido, Tissot

Half-hunter caseCase

A half-hunter case is a pocket-watch case whose lid has a small window or glass in the centre, so the time can be read from the hands without opening the cover. The lid usually carries a ring of hour markers, often in blue enamel. It combines protection with quick reading and is a sought-after variant of the hunter case.

Also called: demi-hunter, demi-savonnette, half hunter

See also: Hunter case, Pocket watch, Case, Enamel dial

Hammer priceMarket and collecting

The final bid accepted by the auctioneer when the hammer falls. It does not include the buyer's premium and taxes, so the total paid by the buyer is higher; published auction results usually show the price including the premium. When comparing auction results with your own watch, check which of the two figures is quoted.

Also called: hammer, knock-down price

See also: Buyer's premium, Estimate, Provenance, Watch appraisal

Guide: Sell a luxury watch

Helium escape valveCase

A helium escape valve is a small valve in the case of some professional dive watches. During saturation diving, tiny helium atoms can enter the case; when the diver decompresses, the valve lets them escape so the pressure does not force the crystal off. It can be automatic or operated manually. Most owners never need it, but it identifies certain diver references.

Also called: HEV, helium valve, helium release valve

See also: Dive watch, ISO 6425, Water resistance, Gasket

Brands: Ball Watch, Delma, Doxa, Maurice de Mauriac

HesaliteCase

Hesalite is a trade name for a type of acrylic glass that Omega uses for crystals, best known from the Speedmaster Professional "Moonwatch". Unlike glass it does not shatter into sharp splinters, which was one reason it was accepted for space use. It scratches easily, but light scratches can be polished away. Many collectors prefer it to sapphire on the Speedmaster for its classic look.

Also called: hesalite crystal, hesalite glass

See also: Acrylic crystal, Crystal, Domed crystal, Chronograph

Hollow linksStraps and bracelets

Hollow links are bracelet links made from rolled or formed sheet metal that is hollow inside, rather than from solid metal. They are lighter and cheaper but wear more quickly and tend to stretch over time. Many vintage bracelets, including older Rolex Oyster and Jubilee bracelets, use hollow links. Hollow end links (HEL) are a related term for the end pieces.

Also called: HEL, hollow end links

See also: Folded links, Solid end links, End links, Bracelet stretch

Guide: Watch condition

Homage watchMarket and collecting

A watch from another brand whose design is closely inspired by a famous model but carries its own name and logo. Homages are legal products, as long as they don't copy trademarks, and are usually inexpensive. They are not fakes, but they have no relation to the original brand and don't share its value.

Also called: homage, tribute watch

See also: Replica watch, Counterfeit watch, Authentication

Guide: Real or fake?

Honest wearMarket and collecting

Normal signs of use – light scratches, small dings, faded lume or a slightly stretched bracelet – that have not been hidden by polishing or replacing parts. Collectors often see honest wear as evidence of originality. It lowers the value less than heavy restoration would, but large dents or damaged dials still count as defects.

Also called: signs of wear, normal wear, wear and tear

See also: Unpolished, Patina, Sharp case, Pre-owned

Guide: Watch condition

Horizontal clutchMovement

A horizontal clutch connects the chronograph by moving a coupling wheel sideways into mesh with the chronograph wheel. It is the traditional system, beautiful to watch through a caseback, but the chronograph hand may jump slightly when started. Many classic and vintage chronographs use it.

Also called: lateral clutch, horizontal coupling, coupling wheel

See also: Vertical clutch, Column wheel, Chronograph, Cam-actuated chronograph

Hunter caseCase

A hunter case is a pocket-watch case with a hinged metal lid that completely covers and protects the dial and crystal. The lid is opened by pressing the crown or a button. Hunters are typically wound at 3 o'clock, while open-face watches are wound at 12. Dents, worn hinges and a lid that no longer springs open properly lower the value.

Also called: savonnette, full hunter, hunting case

See also: Pocket watch, Half-hunter case, Case, Caseback engraving

Brands: Aerowatch

Hybrid watchTypes of movement

A hybrid watch has traditional analogue hands and a quartz movement, combined with connected functions such as step counting, notifications or phone sync, without a full screen. Battery life is long compared with a smartwatch. The term is also used for watches mixing mechanical and electronic elements.

Also called: hybrid smartwatch, connected analogue watch

See also: Smartwatch, Quartz watch, Battery, Spring Drive

Brands: HYT

Hype watchMarket and collecting

A model in such high demand – often driven by social media, celebrities or short supply – that it trades well above retail on the secondary market. Typical signs are long waiting lists and sharply rising prices. Hype can cool down quickly, and prices of such models have fallen markedly in the past, so they are no guaranteed investment.

Also called: hyped watch, hype model

See also: Waiting list, Investment watch, Grey market, Retail price

Guide: Most valuable Swiss watches

I

In-house movementMovement

An in-house movement is designed and produced by the watch brand itself rather than bought from a supplier such as ETA or Sellita. Collectors often pay more for it, and it signals technical independence. On the downside, spare parts are only available from the brand, which can make servicing more expensive.

Also called: manufacture movement, in-house calibre, proprietary movement

See also: Manufacture, Ébauche, ETA, Sellita SW200, Service

Brands: Frederique Constant, Ball Watch, Kari Voutilainen, Perrelet, Speake-Marin, Armin Strom, Audemars Piguet, Cyrus Genève

Guide: How much is my watch worth?

IncablocMovement

Incabloc is a widely used Swiss shock-protection system for the balance, recognisable by its lyre-shaped spring holding the jewel. It is the trademark of a specialist supplier, not of the watch brand, yet the name was often printed on mid-century dials. It has been in use since the 1930s and is still common today.

Also called: Inca-bloc, Incabloc shock protection

See also: Shock protection, KIF, Balance wheel, Jewel bearing

Brands: Armand Nicolet, West End Watch Co.

Index regulatorMovement

An index regulator is a small lever on the balance cock, often marked with plus and minus signs, that shifts two pins along the hairspring to change the rate. Variants include the swan-neck fine adjustment. It is practical and widespread, though free-sprung balances are often considered more stable over time.

Also called: index, swan-neck regulator, raquette

See also: Regulator, Free-sprung balance, Balance cock, Hairspring, Regulation

Integrated bracelet caseCase

An integrated bracelet case is designed so that the bracelet flows directly from the case without visible conventional lugs. The first link is shaped to fit the case. This design defines the luxury sports watches of the 1970s, which remain highly sought after today. A replacement strap usually requires the brand's own fitting.

Also called: integrated bracelet, integrated case

See also: Luxury sports watch, Bracelet, Lug, End links

Brands: Girard-Perregaux, Vacheron Constantin, Audemars Piguet, Chopard, Chronoswiss, Czapek & Cie, Frederique Constant, Gerald Charles

Guide: Most valuable Swiss watches

Investment watchMarket and collecting

A watch bought partly in the hope that it will keep or increase its value. Only a small number of models from a few brands have historically risen above retail, and market prices can also fall. Condition, completeness, rarity and demand are the main drivers; fees, service costs and insurance should be counted when thinking about a return.

Also called: watch investment, investment piece

See also: Hype watch, Retail price, Limited edition, Full-set premium, Watch appraisal

Guide: How much is my watch worth?

ISO 6425Service and water resistance

The international standard for diver's watches. Among other things, it requires water resistance of at least 100 metres, a unidirectional bezel or other device for presetting the dive time, legibility in darkness and resistance to shock, magnetism and salt water. Watches that meet it may be marked "Diver's" followed by the depth, e.g. "Diver's 200 m".

Also called: ISO 6425 diver standard, diver's standard

See also: Dive watch, Water resistance, Unidirectional bezel, Lume, Helium escape valve

Brands: Luminox

Guide: Watch condition

IsochronismPrecision and certificates

The property of a balance and hairspring to oscillate at the same rate regardless of how large the swing is, so the watch keeps the same time whether the mainspring is fully wound or almost run down. Perfect isochronism is impossible; watchmakers improve it with overcoil hairsprings, precise adjustment and constant force mechanisms.

Also called: isochronous, isochrony

See also: Amplitude, Breguet overcoil, Constant force mechanism, Hairspring

Guide: Watch condition

J

Jewel bearingMovement

A jewel bearing is a pierced synthetic ruby fitted into a plate or bridge, in which a steel pivot turns with little friction. Cap jewels on top hold oil in place. Jewel bearings let a movement run for many years with minimal wear, provided it is cleaned and lubricated at proper intervals.

Also called: jewel, ruby bearing, jewelled bearing

See also: Jewels, Gold chatons, Shock protection, Lubrication

JewelsMovement

Jewels are small synthetic rubies or sapphires used as bearings for pivots and as pallet stones, reducing friction and wear. The number, such as 17, 21 or 25 jewels, is often printed on dial or movement. A fully jewelled hand-wound movement needs about 17; higher counts do not automatically mean better quality, and some old watches inflated them for marketing.

Also called: rubies, jewel count, jewelled

See also: Jewel bearing, Gold chatons, Movement, Lubrication

Brands: Ball Watch, Christophe Claret, Hamilton, Roamer

Guide: Real or fake?

Jubilee braceletStraps and bracelets

The Jubilee is a five-piece link bracelet created by Rolex for the Datejust in 1945, with small, semi-circular centre links between flat outer links. It is dressier and more flexible than the Oyster bracelet and is now also offered on GMT-Master II and other models. On two-tone watches the centre links are often gold. Older versions stretch easily, so check for sagging and play between links.

Also called: Rolex Jubilee, five-link bracelet, Jubilee band

See also: Oyster bracelet, President bracelet, Two-tone, Bracelet stretch, GMT watch

Guide: Real or fake?

Jumping hourComplications

A display in which the hour appears as a numeral in a window and jumps instantly to the next number at the top of each hour, while the minutes are shown by a hand or disc. It was fashionable in the 1920s and 1930s and remains a sought-after style. Check that the jump is crisp and the numeral sits centred in the window.

Also called: heure sautante, jump hour, digital hour

See also: Wandering hours, Retrograde display, Date window, Complication

Brands: Franck Muller, Gérald Genta, Hautlence

Guide: How much is my watch worth?

K

Keyless worksMovement

The keyless works are the parts that let you wind the watch and set the hands through the crown, without a separate key as in early pocket watches. They include the winding stem, setting lever, yoke and clutch wheel. Problems here show up as a crown that slips, will not change position or fails to set the time.

Also called: keyless work, winding and setting mechanism

See also: Winding stem, Setting lever, Crown, Manual winding

Guide: Watch condition

KIFMovement

KIF is a Swiss shock-protection system for the balance, made by KIF Parechoc, and the main alternative to Incabloc. Its spring has a different, often three-lobed shape that a watchmaker recognises at a glance. It is used in many Swiss movements, including some high-grade calibres. Like Incabloc it protects the balance pivots from knocks.

Also called: KIF Flector, Kif Parechoc

See also: Shock protection, Incabloc, Balance wheel, Jewel bearing

Kinetic watchTypes of movement

Kinetic is Seiko's name for its quartz watches that generate electricity from wrist movement via a rotor and store it in a rechargeable cell. They combine quartz accuracy with automatic-style winding. When the storage cell ages it must be replaced, which is a common service point on older Kinetic models.

Also called: Seiko Kinetic, automatic quartz, AGS

See also: Quartz watch, Rotor, Solar watch, Battery

Guide: Swiss watch brands A–Z

L

Lacquer dialDial and hands

A lacquer dial is coated with several layers of lacquer, often polished, giving a deep, glossy surface that resembles enamel at first glance. It is less costly to make than enamel and is used on many dress and sports watches. Lacquer can crack, craze or discolour with age and moisture, which collectors judge carefully on vintage pieces.

Also called: lacquered dial, laque dial

See also: Enamel dial, Gloss dial, Dial, Tropical dial

Ladies' watchTypes of watch

A ladies' watch is a model designed and sized for women, traditionally smaller (often below about 30 mm), frequently with jewellery elements such as diamonds or mother-of-pearl dials and often quartz movements. Many modern "ladies'" sizes are worn by everyone. On the pre-owned market small ladies' models usually fetch less than men's versions of the same line, except for precious-metal or jewelled pieces.

Also called: women's watch, lady's watch, ladies' size

See also: Mid-size watch, Case diameter, Mother-of-pearl dial, Quartz watch, Wristwatch

Brands: Armin Strom, Christophe Claret, Eberhard & Co., Eterna, Patek Philippe

Guide: How much is my watch worth?

Leaf handsDial and hands

Leaf hands are shaped like a leaf, with curved edges widening towards the middle and tapering at both ends. They have a classic, elegant look and are used on dress watches and vintage-inspired models. They are sometimes called feuille hands, from the French word for leaf.

Also called: feuille hands, leaf-shaped hands

See also: Alpha hands, Sword hands, Dauphine hands, Dress watch

Brands: IWC Schaffhausen

Leather strapStraps and bracelets

A leather strap is the classic band for dress and everyday watches, made from calf, alligator, ostrich or other hides, usually lined and stitched. It is a wear part: sweat and water age it, so it is normally replaced every few years. Original brand straps with a signed buckle are pleasant to have but rarely affect value much. Leather should not be worn in water, even on a water-resistant watch.

Also called: calfskin strap, leather band

See also: Strap, Alligator strap, Tang buckle, Deployant clasp, Dress watch

Brands: Maurice de Mauriac

Lever escapementMovement

The lever escapement uses a pivoted lever (pallet fork) with two jewelled pallets to lock and release the escape wheel while giving impulse to the balance. Developed in 18th-century England, it became the standard for portable watches because it is robust, self-starting and accurate. Almost every mechanical wristwatch uses a version of it.

Also called: detached lever escapement, anchor escapement

See also: Swiss lever escapement, Escapement, Pallet fork, Escape wheel

Limited editionMarket and collecting

A model produced in a fixed, announced quantity or for a limited period. True limited editions often state the number on the caseback, such as "123/500". Whether a limited edition gains value depends on the quantity, design and demand; many limited pieces trade at or below retail, while a few become highly sought-after.

Also called: LE, limited series, ltd. edition

See also: Numbered edition, Boutique edition, Caseback engraving, Investment watch

Brands: Andersen Genève, Aquastar, Blancpain, Christophe Claret, Daniel Roth, Hautlence

Guide: Most valuable Swiss watches

Linen dialDial and hands

A linen dial has a fine crosshatched texture that resembles woven linen fabric. The pattern is stamped or engraved into the dial base and gives a subtle, matte look. Linen dials appear on vintage dress watches and on modern pieces inspired by them. The effect is decorative and does not change the function of the watch.

Also called: linen-textured dial, crosshatch dial

See also: Dial, Guilloché dial, Matte dial, Dress watch

Lollipop seconds handDial and hands

A lollipop seconds hand has a round luminous disc on its shaft, so it resembles a lollipop. The disc makes it easy to see that the watch is running, even in the dark. It is typical of dive watches. The size and position of the circle varies by brand and era and helps identify correct vintage parts.

Also called: lollipop hand, lollipop

See also: Dive watch, Lume, Mercedes hand, Snowflake hands

LubricationMovement

A mechanical movement needs tiny amounts of different oils and greases at pivots, the escapement and the mainspring. Over the years these lubricants dry out or become contaminated, which increases friction and wear. This is the main reason for regular servicing; a watch that runs badly may simply need to be cleaned and re-oiled.

Also called: oiling, oils, watch oil

See also: Service, Overhaul, Service interval, Jewel bearing

Guide: Watch condition

LugCase

The lugs are the horns projecting from the case that hold the strap or bracelet via spring bars. Their shape, length and the sharpness of their bevels say a lot about a watch's condition. On vintage pieces, collectors check whether the lugs are still thick and crisp or have been rounded off by polishing, which reduces value noticeably.

Also called: lugs, horns

See also: Lug width, Lug-to-lug, Spring bar, Bevel (chamfer), Overpolished case

Guide: Watch condition

Lug widthCase

Lug width is the distance between the inner sides of the two lugs, in millimetres, and it determines which strap or bracelet fits. Common sizes are 18, 20 and 22 mm. Knowing the lug width is essential when buying a replacement strap. An original bracelet with the correct end links for that width adds value.

Also called: strap width, band width

See also: Lug, Strap, End links, Spring bar

Lug-to-lugCase

Lug-to-lug is the length of the watch measured from the tip of the upper lugs to the tip of the lower lugs. It shows how much of the wrist the watch actually covers and often matters more for wearing comfort than the case diameter. A watch whose lugs overhang the wrist looks and feels too large, even if its diameter seems moderate.

Also called: L2L, lug to lug length

See also: Case diameter, Lug, Case thickness

LumeDial and hands

Lume is the collectors' term for the luminous material on hands and markers that makes a watch readable in the dark. Historically it was radium, then tritium, and today it is non-radioactive photoluminescent pigment such as Super-LumiNova, which must be charged by light. The type and colour of lume help date a watch and check whether hands and dial match.

Also called: luminous material, luminescence, luminous paint

See also: Super-LumiNova, Tritium, Radium, Patina lume, Relume

Brands: Ball Watch, Glycine, Luminox, Traser

Lume plotDial and hands

A lume plot is a small dot or area of luminous material on the dial or bezel, for example at the hour markers or at the zero point of a dive bezel. On vintage watches collectors check that the colour and ageing of the plots match those on the hands. Missing, cracked or non-matching lume plots suggest damage or a later restoration.

Also called: lume dot, lume pip, luminous plot

See also: Lume, Patina lume, Relume, Count-up bezel

Guide: Watch condition

LumiNovaDial and hands

LumiNova is a non-radioactive photoluminescent pigment based on strontium aluminate, developed in Japan by Nemoto & Co. It replaced tritium on many watches from the late 1990s and is the base technology behind Super-LumiNova. Like all modern lume, it needs light to charge. Watches with LumiNova are sometimes marked "Swiss Made" alone, without a T.

See also: Super-LumiNova, Tritium, Lume, Swiss T 25

Luxury sports watchTypes of watch

A luxury sports watch combines the robustness of a sports watch with the finishing and prestige of high watchmaking, usually in steel with an integrated bracelet. The category began with the Audemars Piguet Royal Oak (1972) and the Patek Philippe Nautilus (1976), both designed by Gérald Genta. Such models often have long waiting lists and trade above retail on the pre-owned market.

Also called: integrated sports watch, luxury steel sports watch

See also: Integrated bracelet case, Sports watch, Waiting list, Hype watch, Investment watch

Guide: Most valuable Swiss watches

M

Magic LeverMovement

Magic Lever is Seiko's name for its simple and efficient bidirectional winding system, introduced in 1959. A small lever with two claws pushes a ratchet wheel round whichever way the rotor turns, with very few parts. It is found in many Seiko automatic movements and is valued for its reliability.

Also called: Magic-Lever, Seiko Magic Lever

See also: Bidirectional winding, Reverser wheel, Rotor, Automatic watch

Guide: Swiss watch brands A–Z

MagnetismPrecision and certificates

Exposure to magnetic fields from speakers, phone cases, bags or laptops can make the coils of a hairspring stick together, so a mechanical watch suddenly runs very fast, sometimes by minutes a day. Usually nothing is broken: a watchmaker can demagnetise the watch in seconds. Watches with silicon or other non-magnetic parts are largely immune.

Also called: magnetisation, magnetized watch, magnetic field

See also: Demagnetisation, Antimagnetic, Gauss, Hairspring

Brands: Longines, Tissot

Guide: Watch condition

MainplateMovement

The mainplate is the base plate of a movement, usually on the dial side, into which the wheels, bridges and other parts are fitted. It carries holes and recesses for jewels, pivots and screws. On quality movements it is often decorated with perlage. A damaged or corroded mainplate is a serious and costly fault.

Also called: main plate, base plate, pillar plate

See also: Bridge, Perlage, Movement, Jewel bearing

Brands: Armand Nicolet, Genus, Swatch

Guide: Watch condition

MainspringMovement

The mainspring is the coiled spring that stores the energy of a mechanical watch. It is wound by the crown or rotor and slowly unwinds to drive the gear train. Modern mainsprings are made of special alloys that rarely break; older steel springs could lose strength or snap, which is why they are routinely replaced during service.

Also called: main spring, power spring

See also: Barrel, Power reserve, Manual winding, Rotor, Going train

Brands: Perrelet

Guide: Watch condition

Manual windingTypes of movement

A manual-wind or hand-wound watch must be wound by turning the crown, typically once a day. It has no rotor, so the movement can be thinner and is fully visible through a display caseback. Many classic dress watches and chronographs, such as the Omega Speedmaster Professional, use hand-wound movements.

Also called: hand-wound, manual wind, hand winding

See also: Mechanical watch, Automatic watch, Crown, Mainspring, Keyless works

Brands: Cyrus Genève, Aerowatch, Daniel Roth, Favre Leuba, Hamilton, Piaget, Akrivia / Rexhep Rexhepi, Alpina

ManufactureMovement

In watchmaking a manufacture is a company that designs and makes its own movements, or at least their key parts, instead of buying them in. The word is often printed on dials as a claim of independence. How much is really made in-house varies; hairsprings and jewels, for example, are often bought from specialists.

Also called: manufacture d'horlogerie, watch manufacture

See also: In-house movement, Ébauche, Calibre, Swiss Made

Brands: Frederique Constant, Chopard, F.P. Journe, H. Moser & Cie., Movado, Piaget, Vacheron Constantin, Armin Strom

Guide: Swiss watch brands A–Z

Master ChronometerPrecision and certificates

Omega’s name for watches certified by the Swiss Federal Institute of Metrology (METAS), introduced in 2015. The movement must first pass COSC; then the cased watch is tested for accuracy (0 to +5 seconds per day), power reserve, water resistance and resistance to magnetic fields of 15,000 gauss. The term is brand-specific to Omega.

Also called: METAS-certified, Master Chronometer Certified

See also: METAS, COSC, Chronometer, Antimagnetic, Co-Axial escapement

Brands: Omega

Guide: How much is my watch worth?

Matte dialDial and hands

A matte dial has a non-reflective, flat surface. It improves legibility because it does not reflect light, which is why it is typical of tool, military and many dive watches. Matte black dials replaced glossy gilt dials on several sports models from the 1960s. Even ageing to a grey or brownish matte tone can be desirable.

Also called: matt dial, flat dial

See also: Gloss dial, Gilt dial, Tool watch, Tropical dial

Mechanical watchTypes of movement

A mechanical watch runs on the energy of a wound mainspring, released by an escapement and regulated by a balance and hairspring, without any battery. It can be wound by hand or automatically. Mechanical watches dominate the collector market and are the core of Swiss high-end watchmaking.

Also called: mechanical movement, mechanical timepiece

See also: Manual winding, Automatic watch, Quartz watch, Mainspring, Escapement

Guide: How much is my watch worth?

Mercedes handDial and hands

A Mercedes hand is an hour hand with a circle containing three spokes, resembling the Mercedes-Benz star. It is best known from Rolex professional sports models, which use it to make the hour hand easy to tell from the minute hand. The circle holds more luminous material. Wrong proportions are a common detail of fakes.

Also called: Mercedes hour hand, Mercedes hands

See also: Snowflake hands, Lume, Dive watch, Counterfeit watch

Mesh braceletStraps and bracelets

A mesh bracelet is made of finely woven or interlocking metal wire rather than solid links, giving a smooth, flexible band. Variants range from fine Milanese mesh to the heavy "shark mesh" associated with dive watches. Many mesh bracelets have a sliding clasp that allows stepless sizing. Wear shows as broken wires or snagging, which usually cannot be repaired.

Also called: shark mesh, chainmail bracelet, mesh band

See also: Milanese bracelet, Bracelet, Dive watch, Beads-of-rice bracelet

METASPrecision and certificates

The Swiss Federal Institute of Metrology. Together with Omega it developed the Master Chronometer certification, which tests complete watches rather than bare movements, including accuracy of 0 to +5 seconds per day, water resistance and resistance to magnetic fields of 15,000 gauss. Each certified watch can be checked online with its card.

Also called: Swiss Federal Institute of Metrology, METAS certification

See also: Master Chronometer, COSC, Antimagnetic, Gauss

Guide: How much is my watch worth?

Meteorite dialDial and hands

A meteorite dial is cut from a slice of iron meteorite and etched to reveal the crystalline Widmanstätten pattern, a criss-cross structure formed over millions of years. Each dial is therefore unique. Such dials are offered by several luxury brands as a premium option. The material can corrode if not properly treated.

Also called: meteorite face, Widmanstätten dial

See also: Dial, Mother-of-pearl dial, Limited edition, Enamel dial

Micro-adjustmentStraps and bracelets

Micro-adjustment refers to small holes in the side of a clasp where the spring bar can be moved to make the bracelet slightly longer or shorter – typically in steps of a few millimetres. It allows a precise fit between full links. Many modern clasps also have tool-free fine adjustment systems. Worn or enlarged holes can let the spring bar slip and are worth checking.

Also called: micro adjust, fine adjustment, micro-adjust holes

See also: Folding clasp, Spring bar, Glidelock, Easylink, Bracelet

Micro-rotorMovement

A micro-rotor is a small winding rotor set into the level of the movement instead of on top of it, which allows a much thinner automatic watch and leaves most of the movement visible. Universal Genève's Microtor and Patek Philippe's calibre 240 are well-known examples. Micro-rotors are a sign of refined, often higher-priced watchmaking.

Also called: microrotor, integrated rotor, Microtor

See also: Rotor, Peripheral rotor, Automatic watch, Case thickness

Brands: Laurent Ferrier, Universal Genève, Biver, Parmigiani Fleurier, Czapek & Cie, Romain Gauthier, Gerald Charles, Mauron Musy

Guide: Most valuable Swiss watches

Mid-size watchTypes of watch

Mid-size describes a watch between classic ladies' and men's sizes, roughly in the low to mid 30 mm range depending on the brand. Rolex, for example, used "midsize" for Datejust models between its ladies' and men's versions. Mid-size models are popular unisex choices today. The exact size should always be checked in the reference, because listings use the term loosely.

Also called: midsize, medium size, unisex size, boy's size

See also: Ladies' watch, Case diameter, Reference number, Wristwatch

Guide: How much is my watch worth?

Milanese braceletStraps and bracelets

A Milanese bracelet is a finely woven metal mesh band, named after Milan, that feels almost like fabric on the wrist. It is often closed with a sliding or magnetic clasp, so the length can be adjusted without tools. It is typical of dress watches and Bauhaus-style designs. Fine mesh can snag hair and is hard to repair if wires break.

Also called: Milanese loop, Milanese mesh

See also: Mesh bracelet, Bracelet, Dress watch, Folding clasp

Military watchTypes of watch

A military watch is one built to an armed forces' specification and issued to soldiers, pilots or divers, or a civilian watch in that style. Genuine issued pieces often carry markings such as stock numbers, a broad arrow, issue dates or tritium symbols on the dial or caseback. Original issued watches with documented provenance can be very valuable, and fakes, redials and fantasy markings are common.

Also called: mil-spec watch, issued watch, service watch

See also: Field watch, Pilot watch, B-Uhr, Provenance, Redial

Brands: Ollech & Wajs, Traser

Guide: Real or fake?

Mineral crystalCase

A mineral crystal is made of ordinary or hardened glass. It is harder than acrylic and cheaper than sapphire, so it is common on entry-level and many quartz watches. It resists everyday scratches reasonably well but can chip or scratch on hard surfaces, and deep marks cannot be polished out. On a luxury watch that should have sapphire, it suggests a replacement.

Also called: mineral glass, hardened mineral crystal, Hardlex

See also: Crystal, Sapphire crystal, Acrylic crystal, Crystal replacement

Minute repeaterComplications

A chiming complication that sounds the time on demand, usually activated by a slide on the case side: low tones for the hours, double tones for the quarter hours and high tones for the minutes since the last quarter. Small hammers strike gongs inside the case. It is among the most difficult complications to make and adjust, and sound quality is part of a repeater's value.

Also called: répétition minutes, minute repeating, repeater

See also: Quarter repeater, Grande sonnerie, Petite sonnerie, Grand complication

Brands: Ateliers deMonaco, Emile Chouriet, Vacheron Constantin, Armin Strom, Biver, Franck Muller, Gérald Genta, Hublot

Guide: Most valuable Swiss watches

Mirror polishCase

A mirror polish is a highly reflective surface with no visible grain, achieved by polishing with ever finer abrasives. It is used on case flanks, bevels, bezels and parts of bracelets. It shows scratches and fingerprints more readily than brushed metal. Each repolishing removes material, so frequent polishing softens the shape of a case.

Also called: high polish, polished finish, mirror finish

See also: Brushed finish, Overpolished case, Bevel (chamfer), Black polishing

Guide: Watch condition

Monobloc caseCase

A monobloc case has the case middle and back made from a single piece, without a separate caseback. The movement is fitted and removed from the front, after taking off the crystal and bezel. This construction offers few openings and therefore good water resistance, but servicing requires a watchmaker familiar with it.

Also called: monocoque case, one-piece case, mono-block case

See also: Case, Caseback, Water resistance, Dive watch

Brands: Mido

Monopusher chronographComplications

A chronograph operated by a single pusher, usually built into the crown or placed beside it: the first press starts, the second stops and the third resets. It was the norm in early chronographs and is now made mainly by high-end makers. Clean dials and an uncluttered case make vintage monopushers sought after by collectors.

Also called: single-pusher chronograph, mono-pusher, monopoussoir

See also: Chronograph, Column wheel, Pushers, Racing chronograph

Brands: Angelus, De Bethune, Longines

Guide: Most valuable Swiss watches

Moon phaseComplications

A display, usually an aperture with a rotating disc showing a moon, that follows the lunar cycle of about 29.5 days. A simple version with a 59-tooth wheel drifts by about one day every two and a half years and must be corrected; more precise versions need correction only after a century or more. Check that it can be set and that the disc is undamaged.

Also called: moonphase, phase de lune, lunar phase

See also: Complete calendar, Triple calendar, Perpetual calendar, Astronomical complication

Brands: Andreas Strehler, Angelus, Blancpain, Titoni, Aerowatch, Cyrus Genève, De Bethune, IWC Schaffhausen

Guide: How much is my watch worth?

Moonshine GoldMaterials

Moonshine Gold is Omega's name for its own 18k gold alloy, which is paler than classic yellow gold and, according to Omega, more resistant to fading. Omega introduced it in 2019 and uses it mainly on Speedmaster and Constellation models. It is a brand-specific name for a yellow gold alloy, not a separate metal. Hallmarks and papers will still show 18k (750) gold.

Also called: Omega Moonshine Gold

See also: Yellow gold, 18k gold, Gold, Everose gold

Guide: Swiss watch brands A–Z

Mother-of-pearl dialDial and hands

A mother-of-pearl dial is made from a thin slice of the iridescent inner layer of a shell. It shimmers in different colours depending on the light, and no two dials are identical. White, grey and dark (Tahitian) variants exist. It is popular on ladies' watches but also found on men's models. Cracks or delamination reduce the value.

Also called: MOP dial, nacre dial, MOP

See also: Dial, Meteorite dial, Ladies' watch, Enamel dial

MovementMovement

The movement is the engine of a watch: all the parts that store energy, keep time and drive the hands. It may be mechanical (hand-wound or automatic) or quartz. For valuation the movement matters a great deal, because the wrong, replaced or poorly serviced movement can turn a desirable watch into a much cheaper one.

Also called: calibre, mechanism, works

See also: Calibre, Mechanical watch, Quartz watch, In-house movement, Movement finishing

Guide: How much is my watch worth?

Movement finishingMovement

Movement finishing is the decoration and refinement of movement parts: striping, perlage, bevelled and polished edges, polished screw heads and engravings. Good finishing also removes burrs and improves function. It is one of the clearest differences between mass-produced and high-end movements and is an important factor in value.

Also called: finissage, decoration, hand-finishing

See also: Côtes de Genève, Perlage, Anglage, Black polishing, Geneva Seal

Brands: Rudis Sylva, Aerowatch, Daniel Roth, Richard Mille, Vacheron Constantin

Guide: How much is my watch worth?

MSRPMarket and collecting

Manufacturer's suggested retail price – the official price a brand recommends for a new watch, mainly used in the US. In practice it is close to the price at authorised dealers. Listings for pre-owned watches often quote the MSRP for comparison, but the actual market value depends on demand, condition and completeness, not on the MSRP.

Also called: manufacturer's suggested retail price, suggested retail price, list price

See also: Retail price, Authorised dealer (AD), Grey market, Hype watch

Brands: Alpina

Guide: How much is my watch worth?

Multi-axis tourbillonComplications

A tourbillon whose cage rotates on two or three axes at once, with one cage inside another, to average out positional errors in more orientations than a classic tourbillon. It is a technical showpiece made in very small numbers by a few brands and independent watchmakers, and prices are correspondingly high.

Also called: double-axis tourbillon, triple-axis tourbillon, gyrotourbillon, bi-axial tourbillon

See also: Tourbillon, Flying tourbillon, Positional error, Grand complication

Brands: Jaeger-LeCoultre

Guide: Most valuable Swiss watches

N

NATO strapStraps and bracelets

A NATO strap is a single piece of woven nylon that passes under the spring bars and behind the case, with an extra flap that keeps the watch on the wrist if one spring bar fails. It derives from the British Ministry of Defence's G10 strap of the 1970s; the name comes from the NATO stock number. NATO straps are cheap, interchangeable and popular on military and dive watches.

Also called: G10 strap, NATO band, nylon strap

See also: Strap, Military watch, Spring bar, Field watch, Bund strap

Neo-vintageMarket and collecting

A collectors' term for watches from roughly the late 1980s to the early 2000s, a period between classic vintage and current production. Typical neo-vintage pieces already have sapphire crystals and modern movements, but often keep older design details such as tritium lume or smaller case sizes. Interest and prices in this segment have grown, with condition and full sets playing a large role.

Also called: neovintage, modern vintage

See also: Vintage, Tritium, Full set, Pre-owned

Guide: How much is my watch worth?

New old stock (NOS)Market and collecting

A watch or part that was made years ago but never sold or used, often found in old dealer or factory stock. A NOS watch may still have its protective stickers and tags, but the oils may have aged, so a service can be needed despite it being unworn. NOS parts such as original dials or hands are prized for restoring vintage watches correctly.

Also called: NOS, new old stock, old stock

See also: Unworn, Vintage, Aftermarket parts, Service

Brands: Armand Nicolet

Guide: How much is my watch worth?

NivaroxMovement

Nivarox is both a family of hairspring alloys and the name of Nivarox-FAR, the Swatch Group company that is the main maker of hairsprings for the Swiss industry. Nivarox alloys keep their elasticity largely stable across temperature changes. 'Nivarox' on a movement spec means a standard, reliable hairspring.

Also called: Nivarox-FAR, Nivarox hairspring

See also: Hairspring, Silicon hairspring, Glucydur, ETA

Numbered editionMarket and collecting

A limited series in which each watch carries its individual number within the series, usually engraved on the caseback or printed on the dial, e.g. "087/250". The individual number is often recorded on the papers too. Matching numbers on watch and papers support originality; certain numbers, such as 1 or one matching the series name, can attract collectors.

Also called: individually numbered, numbered series

See also: Limited edition, Caseback engraving, Serial number, Box and papers

Brands: Louis Moinet

Guide: Most valuable Swiss watches

O

Observatory chronometerPrecision and certificates

A watch or movement that took part in the precision competitions held at observatories such as Neuchâtel, Geneva and Kew until the late 1960s, when quartz made them obsolete. Specially prepared movements competed for accuracy rankings and prizes. Observatory pieces with original certificates are rare and highly prized by collectors.

Also called: chronomètre d'observatoire, observatory trial watch

See also: Chronometer, Chronometer certificate, COSC, Accuracy

Guide: Most valuable Swiss watches

OverhaulService and water resistance

A complete service in which the movement is fully dismantled, cleaned, inspected, lubricated, reassembled and regulated, often combined with case refinishing and new gaskets. The term distinguishes this from smaller jobs like a battery change or regulation. Caution for vintage pieces: refinishing during an overhaul can reduce the value, so collectors often ask for no polishing.

Also called: full service, complete service, revision

See also: Service, Lubrication, Regulation, Parts replacement, Overpolished case

Guide: Watch condition

Overpolished caseMarket and collecting

A case that has been polished so often or so heavily that it has lost material and its original shape. Typical signs are rounded, soft edges, thin lugs, washed-out bevels and blurred engravings or hallmarks. Polishing cannot be undone, so overpolishing is one of the main reasons why vintage watches lose value compared with sharp, original examples.

Also called: over-polished, overpolished, polished out

See also: Sharp case, Unpolished, Mirror polish, Bevel (chamfer), Lug

Brands: Patek Philippe, Richard Mille

Guide: Watch condition

Oyster braceletStraps and bracelets

The Oyster bracelet is Rolex's sporty three-piece link bracelet: broad, flat outer links with a narrower centre link, usually brushed with polished edges in modern versions. It is fitted to most Rolex sports models and many Datejusts. Older versions had folded or hollow links and are prone to stretch; newer ones use solid links and solid end links. The clasp code and end-link number help to date and verify it.

Also called: Rolex Oyster bracelet, three-link bracelet

See also: Jubilee bracelet, President bracelet, Oyster case, Solid end links, Bracelet stretch

Guide: Real or fake?

Oyster caseCase

The Oyster case is Rolex's name for its water-resistant case, patented in 1926, with a screw-down caseback, screw-down crown and sealed crystal. It is the base of most Rolex models, from the Submariner to the Datejust, which is why they are called Oyster or Oyster Perpetual. The term is specific to Rolex and its sister brand Tudor.

Also called: Rolex Oyster case, Oyster

See also: Screw-down crown, Screw-down caseback, Water resistance, Oyster bracelet, Oystersteel

Brands: Rolex

Guide: Swiss watch brands A–Z

OystersteelMaterials

Oystersteel is Rolex's own name for the 904L-family stainless steel it uses for its steel cases and bracelets. The term appears in Rolex catalogues and on newer warranty cards in place of "stainless steel". It is a marketing name for the material, not a different metal from what Rolex used before the name was introduced. For valuation, the reference number and condition matter far more than the steel name.

Also called: Rolex Oystersteel, 904L

See also: 904L steel, 316L steel, Oyster case, Oyster bracelet, Stainless steel

Guide: Swiss watch brands A–Z

P

PalladiumMaterials

Palladium is a white precious metal of the platinum group, lighter and less expensive than platinum but with a similar colour. It is used both as a case metal in its own right (usually 950 palladium) and as an alloying element in white gold. Palladium watches are relatively uncommon, so they can be confused with steel or white gold; the hallmark settles the question.

Also called: Pd, 950 palladium, Pd950

See also: Platinum, White gold, Gold, Precious metal hallmark

Guide: How much is my watch worth?

Pallet forkMovement

The pallet fork is the lever of the lever escapement. Two jewelled pallet stones lock and release the escape wheel, while the fork end receives and gives impulse to the balance. Its precise adjustment matters for a healthy beat. Pallet forks in silicon are used by some brands for lower friction and antimagnetic properties.

Also called: pallet lever, anchor, pallets

See also: Escapement, Escape wheel, Balance wheel, Lever escapement, Beat error

Panda dialDial and hands

A panda dial is a chronograph dial that is white or silver with black subdials, resembling a panda's face. It is a collectors' nickname and has become popular on both vintage and modern chronographs. Original vintage panda dials, for instance on certain classic chronographs, can carry significant premiums, so they are a frequent target of redials.

Also called: panda

See also: Reverse panda dial, Chronograph, Subdial, Redial, Tuxedo dial

Brands: Universal Genève

Guide: Most valuable Swiss watches

Parachrom hairspringMovement

Parachrom is Rolex's name for its hairspring made of a paramagnetic alloy containing niobium and zirconium. Rolex states that it is much less affected by magnetic fields and shocks than traditional springs. Its blue-coloured version is called Blue Parachrom. It appears in most current Rolex movements.

Also called: Parachrom, Blue Parachrom, Parachrom Blu

See also: Hairspring, Silicon hairspring, Antimagnetic, Superlative Chronometer

Guide: Swiss watch brands A–Z

Parts replacementService and water resistance

The exchange of worn or damaged components during service or repair, for example the mainspring, crown, hands, bezel insert, dial or crystal. Manufacturers often replace old parts with new ones during service, sometimes returning the old parts on request. For vintage watches, replaced parts such as service dials can reduce value, so ask for originals to be kept.

Also called: replacement parts, part exchange, service parts

See also: Service dial, Aftermarket parts, Service papers, Overhaul, Franken watch

Brands: Angelus, Certina, Rolex, Squale

Guide: Watch condition

PatinaMarket and collecting

The natural ageing of materials over time: dials that fade or turn brown, lume that changes colour, bezels that fade and bronze or gold that darkens. Even, attractive patina is valued by collectors and can raise the price of a vintage watch. Artificially created patina, such as fauxtina on modern watches, does not carry the same appeal.

Also called: aged, aging

See also: Patina lume, Tropical dial, Fauxtina, Ghost bezel, Vintage

Guide: Watch condition

Patina lumeDial and hands

Patina lume is luminous material that has aged naturally, changing from white or green to cream, yellow, orange or brown. It is typical of tritium and radium dials. Collectors value even, matching patina on hands and dial as a sign that the parts belong together and have never been replaced. Mismatched shades suggest replaced hands or a relume.

Also called: aged lume, patinated lume, creamy lume

See also: Patina, Tritium, Fauxtina, Lume plot, Relume

Guide: Real or fake?

Peripheral rotorMovement

A peripheral rotor is a ring-shaped winding weight that turns around the outer edge of the movement rather than across it. The movement stays fully visible and the watch can be thin. It is technically demanding and rare; Carl F. Bucherer's calibre A1000 is one example.

Also called: peripheral winding, rim rotor, orbital rotor

See also: Rotor, Micro-rotor, Automatic watch, Display caseback

Brands: Carl F. Bucherer, Charles Girardier, DeWitt

Guide: Most valuable Swiss watches

PerlageMovement

Perlage is a decoration of small overlapping circles, made with a rotating abrasive peg, often applied to the mainplate and sometimes to bridges. It is also found under the dial, where it is hidden from view. The regularity of the circles shows the care taken, and it is one of the classic elements of Swiss movement finishing.

Also called: circular graining, pearling, spotting

See also: Movement finishing, Côtes de Genève, Mainplate, Anglage

Perpetual calendarComplications

A calendar mechanism that automatically accounts for months of different lengths and leap years, so the date stays correct without manual adjustment for decades; most only need a correction in 2100, which is not a leap year. It usually shows date, day, month and a leap-year cycle, often with a moon phase. Setting it the wrong way can damage it, so a service history matters.

Also called: QP, quantième perpétuel, perpetual

See also: Annual calendar, Complete calendar, Moon phase, Grand complication

Brands: Patek Philippe, Ulysse Nardin, MB&F, IWC Schaffhausen, Ateliers deMonaco, Daniel Roth, H. Moser & Cie., Rolex

Guide: Most valuable Swiss watches

Petite sonnerieComplications

A striking mode that chimes the hours on the hour and the quarters at each quarter, without repeating the hour at every quarter as a grande sonnerie does. It is often offered as a setting on grande sonnerie watches rather than as a separate mechanism. Like all striking watches, it is a high-end complication.

Also called: small strike, petite sonnerie au passage

See also: Grande sonnerie, Minute repeater, Quarter repeater, Complication

Brands: Philippe Dufour

Guide: Most valuable Swiss watches

Pilot watchTypes of watch

A pilot watch is designed for aviators: a large, highly legible dial, strong luminous markings, an oversized crown that can be operated with gloves and often a chronograph, slide rule or second time zone. Historic types include the German Flieger and B-Uhr and the Breitling Navitimer with its slide-rule bezel. Original military-issued pilot watches are collectible, and redialled or assembled examples are common.

Also called: aviator watch, aviation watch, pilot's watch

See also: Flieger watch, B-Uhr, Slide-rule bezel, GMT watch, Military watch

Brands: IWC Schaffhausen, Ollech & Wajs, Oris, Aquastar

Guide: How much is my watch worth?

PlatinumMaterials

Platinum is a dense, white precious metal used for top-of-the-range watches. Watch cases are usually 950 platinum (95 % pure), stamped 950 or PT950. It is noticeably heavier than gold and steel, does not tarnish, and is harder to work, which is why platinum models are rare and expensive. Brands often signal platinum discreetly, for example with an ice-blue dial or a small diamond at six o'clock.

Also called: Pt, PT950, 950 platinum, plat

See also: White gold, Palladium, Gold, Precious metal hallmark, Tantalum

Brands: Akrivia / Rexhep Rexhepi, Philippe Dufour, F.P. Journe, Haldimann, Parmigiani Fleurier

Guide: Most valuable Swiss watches

Pocket watchTypes of watch

A pocket watch is a watch carried in a pocket, usually on a chain, with the crown typically at twelve o'clock. Open-face models show the dial directly, while hunter cases have a hinged lid over the dial. Most are hand-wound, and many antique examples have gold, silver or gold-filled cases. Ordinary pocket watches are often worth little beyond metal value, but complicated or important makers' pieces can be very valuable.

Also called: fob watch, open-face watch

See also: Hunter case, Half-hunter case, Wristwatch, Trench watch, Gold-filled

Brands: Audemars Piguet, Tissot, Vacheron Constantin, Czapek & Cie, IWC Schaffhausen, Patek Philippe, Andreas Strehler, Ball Watch

Guide: How much is my watch worth?

Positional errorPrecision and certificates

The difference in rate a watch shows depending on how it is held, for example dial up, dial down or crown up. It is caused by gravity acting on an imperfectly balanced balance wheel. Watchmakers reduce it by adjustment in several positions; the tourbillon was invented to average it out in vertical positions.

Also called: position error, delta, positional variation

See also: Accuracy, Timegrapher, Tourbillon, Regulation

Guide: Watch condition

Power reserveMovement

Power reserve is how long a fully wound mechanical watch runs before it stops. Many traditional automatic movements run for roughly 38 to 48 hours; modern ones often reach 70 hours or more, and some run for days. A noticeably short reserve can indicate a worn mainspring or a movement in need of service.

Also called: running time, autonomy, reserve de marche

See also: Mainspring, Barrel, Twin barrel, Power reserve indicator

Brands: Cyrus Genève, Oris, Schwarz Etienne, Armin Strom, Daniel Roth, Favre Leuba, Hublot, Parmigiani Fleurier

Guide: Watch condition

Power reserve indicatorComplications

A hand or display showing how much energy remains in the mainspring, typically in hours or as an up-down scale, so you know when a manual watch needs winding. Also called “réserve de marche” or “up/down indicator”. It is common on hand-wound high-end watches and on watches with long power reserves.

Also called: power reserve display, réserve de marche, up-down indicator, auf/ab

See also: Power reserve, Mainspring, Barrel, Manual winding

Brands: Kari Voutilainen, Louis Erard, Zodiac

Guide: How much is my watch worth?

Pre-ownedMarket and collecting

The trade's term for a used watch, i.e. one that has had at least one previous owner. It covers anything from nearly new to heavily worn, so condition, service history and completeness matter more than the label itself. Pre-owned watches are sold by private sellers, independent dealers, auction houses and, increasingly, through manufacturers' own certified programmes.

Also called: used, second-hand, preowned, previously owned

See also: Certified pre-owned (CPO), Vintage, Unworn, Honest wear, Grey market

Guide: Sell a luxury watch

Precious metal hallmarkMaterials

A hallmark is an official stamp on a gold, platinum, palladium or silver case confirming its fineness, typically together with a fineness number (such as 750, 950 or 925) and the maker's responsibility mark. Switzerland has its own official control marks, and the international Convention mark (a pair of scales) is recognised in many countries. Hallmarks help separate solid metal from plating and are worth checking closely, as fakes often get them wrong.

Also called: poinçon, assay mark, control mark, fineness mark, Convention mark

See also: 18k gold, Gold, Platinum, Caseback, Counterfeit watch

Guide: Real or fake?

President braceletStraps and bracelets

The President is the Rolex bracelet with semi-circular three-piece links, introduced with the Day-Date and fitted only to precious-metal models (gold or platinum). It typically has a hidden crown clasp. The name links to the Day-Date's nickname "President". A President-style bracelet on a steel watch is either an aftermarket part or not a genuine Rolex combination.

Also called: Rolex President, Presidential bracelet

See also: Oyster bracelet, Jubilee bracelet, Day-date display, Gold, Aftermarket parts

Guide: Real or fake?

Pressure testService and water resistance

A test of water resistance in which the watch is exposed to air or water pressure in a testing device, without needing to be opened. Dry tests measure whether the case deforms or loses air; wet tests check for bubbles. Watchmakers recommend a pressure test after every opening, after crystal or gasket replacement and at regular intervals.

Also called: water resistance test, leak test, waterproof test

See also: Water resistance, Gasket replacement, ATM, Service

Guide: Watch condition

Printed indicesDial and hands

Printed indices are hour markers that are printed onto the dial, often with pad printing, rather than applied as separate metal parts. They are flat and simpler to produce, and common on tool, military and entry-level watches. Sharp, even printing is a sign of an original dial; blurred or thick printing can indicate a redial or a fake.

Also called: printed markers, painted indices

See also: Applied indices, Dial, Redial, Lume

ProvenanceMarket and collecting

The documented history of a watch: who bought it, who owned it and where it has been, supported by receipts, papers, archive extracts, letters or photographs. Clear provenance strengthens trust in authenticity. A notable former owner or a documented first-owner history can raise the price considerably, especially at auction.

Also called: ownership history, history

See also: Extract from the Archives, Box and papers, Hammer price, Authentication

Brands: Akrivia / Rexhep Rexhepi, Mathey-Tissot, Philippe Dufour, Andersen Genève, Andreas Strehler, Breitling, Genus, Haldimann

Guide: Most valuable Swiss watches

PulsometerComplications

A chronograph scale used by doctors to measure a pulse rate: start the chronograph, count a set number of beats (marked on the scale, often 15 or 30) and stop; the seconds hand then shows beats per minute. It is typically found on vintage chronographs and gives them a medical-instrument character that some collectors specifically look for.

Also called: pulsation scale, pulsograph, doctor's dial

See also: Chronograph, Telemeter, Tachymeter, Decimal scale

Guide: Most valuable Swiss watches

PushersCase

Pushers are buttons on the case side used to operate functions such as starting, stopping and resetting a chronograph, or correcting a calendar. On most chronographs they sit at 2 and 4 o'clock. Their shape (round, rectangular, pump-style) depends on the model and era. Non-original pushers reduce the value of a collectible chronograph.

Also called: push-pieces, push buttons, chronograph pushers

See also: Chronograph, Screw-down pushers, Monopusher chronograph, Crown

Brands: Breitling, Angelus, Eberhard & Co., Gallet

PVD coatingMaterials

PVD (physical vapour deposition) is a process that deposits a thin, hard layer of metal or ceramic compounds onto a case in a vacuum. It is used to create black, gunmetal, blue or gold-coloured finishes on steel or titanium. PVD is harder than electroplating but can still scratch or wear at edges, and worn coating cannot be touched up locally. Gold-coloured PVD is not solid gold.

Also called: PVD, physical vapour deposition, IP plating, ion plating

See also: DLC coating, Gold-plated, Stainless steel, Titanium

Guide: Watch condition

Q

Qualité FleurierPrecision and certificates

A Swiss certification founded in 2001 by watchmakers in the Fleurier region, including Chopard, Parmigiani Fleurier and Bovet. It requires a COSC-certified movement, high-quality finishing, parts made entirely in Switzerland and a test of the finished watch simulating daily wear. It is rarer than the Geneva Seal and found on a small number of high-end models.

Also called: Fleurier Quality Foundation, QF

See also: Geneva Seal, COSC, Movement finishing, Chronometer

Guide: How much is my watch worth?

Quarter repeaterComplications

A chiming watch that sounds the hours and the quarter hours on demand, but not the individual minutes. It was common in pocket watches before the minute repeater became the standard for high-end chiming watches. Quarter repeaters remain less expensive than minute repeaters, but working, well-preserved examples are still valued.

Also called: quarter-hour repeater, répétition quarts

See also: Minute repeater, Petite sonnerie, Pocket watch, Grande sonnerie

Guide: Most valuable Swiss watches

Quartz crisisTypes of movement

The quartz crisis describes the period in the 1970s and early 1980s when cheap, accurate quartz watches, largely from Japan, plunged the Swiss mechanical watch industry into deep trouble. Many brands closed or merged and employment fell sharply. The recovery was helped by Swatch and later by a renewed passion for mechanical watches.

Also called: quartz revolution

See also: Quartz watch, Mechanical watch, Swiss Made, Vintage

Brands: Breitling, Epos, Armand Nicolet, Audemars Piguet, Biver, Blancpain, Chronoswiss, Doxa

Quartz watchTypes of movement

A quartz watch keeps time with a quartz crystal that vibrates at a precise frequency, usually 32,768 Hz, when powered by a battery. It is far more accurate than a typical mechanical watch and needs little maintenance apart from battery changes. Most quartz watches fetch lower prices on the secondary market than comparable mechanical watches.

Also called: quartz, battery watch

See also: Battery, Mechanical watch, Quartz crisis, Thermocompensated quartz

Guide: How much is my watch worth?

Quick-release spring barsStraps and bracelets

Quick-release spring bars have a small lever on the bar itself, so a strap or bracelet can be removed by hand without a spring-bar tool. They make swapping straps quick and avoid scratches on the lugs. They are common on aftermarket straps and on watches from brands with interchangeable strap systems. Their levers should click firmly in place to prevent the strap from coming loose.

Also called: quick release pins, quick-change spring bars, QR spring bars

See also: Spring bar, Strap, Lug, Lug width

R

Racing chronographTypes of watch

A racing chronograph is a chronograph designed for timing motor races, usually with a tachymeter scale on the bezel or dial to read speed over a known distance and strongly contrasting subdials. Classic examples include the Heuer Carrera and Autavia, the Rolex Daytona and the Omega Speedmaster, which began as a racing chronograph. Vintage racing chronographs with original dials are highly collectible.

Also called: motorsport chronograph, racing chrono

See also: Chronograph, Tachymeter, Panda dial, Tachymeter bezel, Sports watch

Brands: Delma, TAG Heuer

Guide: Most valuable Swiss watches

Radio-controlled watchTypes of movement

A radio-controlled watch receives time signals from transmitters, such as DCF77 in Germany or WWVB in the USA, and corrects itself automatically. It is therefore always exact as long as it gets a signal. These watches are usually quartz, often solar-powered, and are practical rather than collectable.

Also called: atomic watch, radio watch, RC watch

See also: Quartz watch, Solar watch, Accuracy, Battery

RadiumDial and hands

Radium was the first self-luminous material used on watch dials, from the early 20th century until it was replaced by tritium around the middle of the century. It glowed without charging but is highly radioactive and remains so for centuries. Radium dials should not be opened or restored without precautions. Original radium dials are collectible but must be handled carefully.

Also called: radium lume, radium paint

See also: Tritium, Lume, Patina lume, Vintage

Railway minute trackDial and hands

A railway minute track is a minute scale around the dial that looks like a railway track: two parallel lines crossed by short strokes for each minute. It gives precise reading of minutes and seconds and was common on early wristwatches, railroad pocket watches and military pieces. It is now often used on vintage-inspired designs.

Also called: railroad track, chemin de fer, railroad minute track

See also: Chapter ring, Rehaut, Dial, Sector dial

Rattrapante (split-seconds chronograph)Complications

A chronograph with two superimposed seconds hands that start together; one can be stopped to read an intermediate or lap time while the other keeps running, then made to “catch up” with it. You can usually spot it by an extra pusher, often in or beside the crown. It is one of the most demanding chronograph mechanisms to build and service, which is reflected in price.

Also called: split-seconds chronograph, split-second chronograph, doppelchronograph, double chronograph

See also: Chronograph, Flyback chronograph, Column wheel, Grand complication

Brands: Franck Muller, Dubey & Schaldenbrand, Parmigiani Fleurier

Guide: Most valuable Swiss watches

RedialDial and hands

A redial is an original dial that has been refinished: stripped, repainted and reprinted, often to hide damage. Good redials can be hard to spot, but typical signs are blurred or uneven printing, wrong fonts, misplaced text and fresh lume. For collectible watches a redial reduces the value substantially compared with an original dial.

Also called: refinished dial, restored dial, repainted dial

See also: Service dial, Dial, Relume, Franken watch, Authentication

Brands: Certina

Guide: Real or fake?

Reference numberMarket and collecting

The model code a manufacturer gives a specific version of a watch, often combining case material, bezel, dial or bracelet variants (for example Rolex 116610LN or Patek Philippe 5711/1A). It is usually engraved between the lugs, on the caseback or printed on the papers. The reference is the starting point for identifying a watch, checking its originality and comparing prices, because small reference differences can change value considerably.

Also called: ref., ref, model number, reference

See also: Serial number, Calibre number, Box and papers, Watch appraisal, Authentication

Guide: How much is my watch worth?

Regatta timerInstruments and scales

A countdown function for sailing races, which typically start after a five- or ten-minute countdown with visual and acoustic signals. The watch shows the minutes remaining, often in coloured segments, so the crew can cross the line exactly at the start. A well-known example is the Rolex Yacht-Master II.

Also called: regatta countdown, yacht timer, sailing timer

See also: Countdown timer, Countdown bezel, Chronograph, Tide indicator

Guide: How much is my watch worth?

RegulationPrecision and certificates

Adjusting the rate of a watch so that it gains or loses as little as possible, usually by moving the regulator or turning screws on a free-sprung balance. Regulation is part of every service but can also be done on its own if a watch runs too fast or slow. A watch that cannot be regulated well usually needs a full service.

Also called: regulating, rate adjustment, adjustment

See also: Regulator, Timegrapher, Accuracy, Free-sprung balance, Service

Guide: Watch condition

RegulatorMovement

In a movement, the regulator is the device used to adjust the rate, usually an index arm that changes the effective length of the hairspring. Moving it toward plus or minus makes the watch run faster or slower. A watchmaker uses it during regulation. Do not confuse it with a regulator dial, which is a dial layout.

Also called: regulating device, regulator index

See also: Index regulator, Free-sprung balance, Regulation, Regulator dial

Brands: Louis Erard, Chronoswiss, Ernest Borel, Auguste Reymond, Revue Thommen

Regulator dialComplications

A dial layout in which hours, minutes and seconds each have their own hand, usually with the minutes in the centre and hours and seconds in separate subdials. It is derived from the precision regulator clocks used in workshops to set other timepieces, where reading the minutes clearly was most important.

Also called: régulateur, regulator layout, regulateur

See also: Subdial, Small seconds, Dial, Chronometer

Brands: Chronoswiss, Louis Erard

Guide: How much is my watch worth?

RehautDial and hands

The rehaut is the inner bevelled ring between the dial and the crystal, sloping down to the dial edge. It often carries a minute track, and some brands engrave it with their name and the serial number to make counterfeiting harder. A correct, well-aligned rehaut engraving is one of the details checked when authenticating certain modern watches.

Also called: flange, inner bezel ring, dial flange

See also: Chapter ring, Dial, Serial number, Counterfeit watch

Brands: Rolex

Guide: Real or fake?

RelumeDial and hands

A relume is the replacement of aged or lost luminous material on dial or hands with fresh lume. It restores legibility, but for vintage collectors it lowers value because the original material is lost. A relume often shows as lume that is too bright, unevenly applied or a different colour from the rest of the watch.

Also called: relumed, reluming, relumed hands

See also: Lume, Redial, Patina lume, Fauxtina

Brands: Omega

Guide: Watch condition

RemontoireComplications

A small secondary spring that is rewound at regular intervals, often every second, by the mainspring and then drives the escapement with constant force. It reduces the effect of a weakening mainspring on accuracy and often produces a visible or jumping seconds motion. It is one of the most common forms of constant force mechanism.

Also called: remontoir, remontoir d'égalité, constant-force remontoire

See also: Constant force mechanism, Dead-beat seconds, Fusee and chain, Mainspring

Brands: F.P. Journe, Andreas Strehler

Guide: Most valuable Swiss watches

Replica watchMarket and collecting

A copy of a branded watch that imitates its design and logos and is sold as a "replica" – in plain terms, a fake. Quality ranges from crude to very convincing, so details like engravings, finishing, the movement and weight need careful checking. Replicas have no collector value, and buying or selling them can be illegal depending on the country.

Also called: rep, fake, copy watch, super clone

See also: Counterfeit watch, Homage watch, Authentication, Franken watch

Guide: Real or fake?

Retail priceMarket and collecting

The price at which a brand's authorised dealers and boutiques sell a new watch, set by the manufacturer per country. Brands often raise it over time, which also influences the value of pre-owned pieces. Secondary-market prices can be well below retail for most watches and above it for scarce, in-demand models, so retail price alone says little about resale value.

Also called: list price, RRP, recommended retail price

See also: MSRP, Authorised dealer (AD), Grey market, Investment watch

Guide: How much is my watch worth?

Retrograde displayComplications

A hand that moves along an arc instead of a full circle and, at the end of the scale, snaps back to the start. It is used for minutes, seconds, date or day of the week. The flyback must happen cleanly; a hand stuck midway or jumping irregularly points to a worn or damaged mechanism.

Also called: retrograde, rétrograde, retrograde hand

See also: Jumping hour, Wandering hours, Big date, Complication

Brands: Gérald Genta, Cyrus Genève, Hautlence, Roger Dubuis, Schwarz Etienne, Chronoswiss, Perrelet, Urwerk

Guide: How much is my watch worth?

Reverse panda dialDial and hands

A reverse panda dial is a chronograph dial in black with white or silver subdials, the inverse of a panda dial. It is a collectors' nickname and is found on many vintage and modern racing chronographs. Correct contrast, printing and patina are checked carefully on vintage examples, because rare original versions are often faked.

Also called: reverse panda, inverse panda

See also: Panda dial, Chronograph, Subdial, Racing chronograph

Brands: Zenith

Guide: Most valuable Swiss watches

Reverser wheelMovement

A reverser wheel is a small wheel with a one-way mechanism that lets the rotor wind in both directions, changing the direction of motion into a single winding direction. Many automatics such as the ETA 2824 use them. Worn reversers are a common reason for weak winding and are replaced during service.

Also called: reversing wheel, reverser

See also: Bidirectional winding, Rotor, Magic Lever, ETA 2824-2

Reversible case watchTypes of watch

A reversible case watch has a case that can be flipped over in its frame so that the dial is turned towards the wrist and protected. The best-known example is the Jaeger-LeCoultre Reverso, created in 1931 for polo players. The solid back can be engraved, and some models have a second dial on the reverse. The swivel mechanism should be checked for play and wear.

Also called: Reverso, swivel case watch, flip case watch

See also: Tank watch, Caseback engraving, Dual time, Dress watch

Guide: Swiss watch brands A–Z

Roman numeralsDial and hands

Roman numerals (I, II, III …) are a classic way of marking the hours on dress and pocket watches. Traditionally the four is often shown as IIII rather than IV, partly for visual balance with VIII on the opposite side. They can be printed, painted on enamel or applied. Roman numerals give a formal, timeless look.

Also called: roman numbers, roman hour markers

See also: Arabic numerals, Breguet numerals, Dress watch, Enamel dial

Brands: Claude Bernard

Rose goldMaterials

Rose gold is gold alloyed with a higher share of copper, which gives a pink to reddish tone. Swiss watches use 18k rose gold; the exact shade varies between brands and has changed over the decades. Older red gold alloys could fade or discolour, while brands now market fade-resistant versions such as Rolex Everose and Omega Sedna gold. On papers it may be called pink gold or red gold.

Also called: pink gold, red gold, RG, PG, 18k rose gold

See also: Gold, 18k gold, Everose gold, Yellow gold, Two-tone

Brands: F.P. Journe, Akrivia / Rexhep Rexhepi, Purnell, Ferdinand Berthoud, Gerald Charles, Haldimann, Rudis Sylva, Simon Brette

Guide: How much is my watch worth?

Rotating bezelCase

A rotating bezel is a ring around the crystal that can be turned to use a scale printed or engraved on it. Depending on the scale it measures elapsed time, counts down, shows a second time zone or serves as a compass or slide rule. It can turn in one direction or both. Smooth, precise clicks and an original insert are signs of good condition.

Also called: turning bezel, timing bezel

See also: Unidirectional bezel, Bidirectional bezel, Count-up bezel, 24-hour bezel, Compass bezel

Brands: Blancpain, Claude Bernard, Doxa, Gallet

RotorMovement

The rotor is the semicircular weight in an automatic watch that turns with the movement of the wrist and winds the mainspring. It is visible through a display caseback and is often engraved or decorated with the brand's name. Some high-end rotors are made of gold for extra weight. A noisy or scraping rotor usually needs attention.

Also called: oscillating weight, winding rotor, oscillating mass

See also: Automatic watch, Micro-rotor, Peripheral rotor, Bidirectional winding

Brands: Perrelet, Eterna, Oris, Carl F. Bucherer, Charles Girardier, Richard Mille, Rolex, DeWitt

Rubber strapStraps and bracelets

A rubber strap is made of natural or synthetic rubber (often vulcanised rubber or FKM fluoroelastomer) and is the standard choice for dive and sports watches because it is waterproof, comfortable and easy to clean. Cheaper silicone straps look similar but attract dust and wear faster. Many brands make fitted rubber straps that follow the case shape. Old rubber can harden, crack or become sticky and is simply replaced.

Also called: FKM strap, vulcanised rubber strap, silicone strap, caoutchouc strap

See also: Strap, Tropic strap, Dive watch, Sports watch, Deployant clasp

Brands: Hublot, Patek Philippe

S

Sandwich dialDial and hands

A sandwich dial consists of two layers: a top plate with cut-out numerals and markers, and a lower plate coated with luminous material. The lume shows through the openings, giving deep, very legible markers. Panerai is the brand most associated with this design, and other makers use it too. Original vintage sandwich dials are valuable and carefully examined.

Also called: two-layer dial, Panerai sandwich dial

See also: Dial, Lume, Super-LumiNova, Lume plot

Sapphire caseMaterials

A sapphire case is machined from synthetic sapphire crystal, the same material as watch glasses, making the whole case transparent or tinted. Sapphire is extremely hard and scratch-resistant but brittle, and cutting and polishing a full case takes very long, so such watches are expensive and usually limited. Brands such as Hublot and Richard Mille are known for them. Chips or cracks mean replacing the part.

Also called: sapphire crystal case, transparent case

See also: Sapphire crystal, Ceramic, Skeleton watch, Limited edition

Brands: Corum

Guide: Most valuable Swiss watches

Sapphire crystalCase

A sapphire crystal is made of synthetic sapphire, an extremely hard material that only diamond and very few other substances can scratch. It is standard on most modern quality watches. It is identified by its cool, very clear look; a drop of water stays beaded on it. It can shatter under a hard blow, and it often carries an anti-reflective coating.

Also called: sapphire glass, synthetic sapphire

See also: Crystal, Mineral crystal, Acrylic crystal, Anti-reflective coating, Sapphire case

Brands: Rado, Claude Bernard, Corum

Screw-down casebackCase

A screw-down caseback is threaded and screwed into the case middle, sealing the case with a gasket. It is opened with a special tool that grips notches or flats on the back. This design gives better water resistance than a snap-on back and is used on most sports and dive watches. Tool marks around the notches show earlier openings.

Also called: screw-in caseback, screw-back, threaded caseback

See also: Caseback, Snap-on caseback, Gasket, Water resistance, Oyster case

Screw-down crownCase

A screw-down crown is screwed onto a threaded tube in the case, pressing against gaskets to seal the opening. You unscrew it before winding or setting and screw it back in afterwards. It is a key element of water resistance in dive and sports watches. Worn threads or old seals compromise water resistance, so check them during a service.

Also called: screw-in crown, screw-lock crown

See also: Crown, Gasket, Water resistance, Oyster case, Screw-down pushers

Brands: Rolex, Wenger

Guide: Watch condition

Screw-down pushersCase

Screw-down pushers have threaded collars that are screwed down over the chronograph buttons to lock and seal them. This prevents accidental operation and improves water resistance. To use the chronograph you must unscrew them first. They are known from some sports chronographs, and their presence or absence helps identify the reference and period.

Also called: screw-locked pushers, screw-in pushers

See also: Pushers, Screw-down crown, Water resistance, Chronograph

Seconds per dayPrecision and certificates

The usual unit for a watch’s rate: how many seconds it gains (+) or loses (−) in 24 hours. Mechanical watches are commonly measured this way on a timegrapher, quartz watches more often in seconds per month or year. Note that the rate varies with position, temperature and state of wind, so a single reading is only an indication.

Also called: s/d, spd, sec/day, daily rate

See also: Accuracy, Timegrapher, Positional error, COSC

Guide: Watch condition

Sector dialDial and hands

A sector dial divides the face into zones with concentric circles and radial lines, often combining different finishes or colours. The style was popular in the 1930s and 1940s and is regularly revived on modern watches. Original period sector dials in good condition are sought after, while restored ones are worth considerably less.

Also called: scientific dial, sectored dial

See also: Dial, Railway minute track, Vintage, Chapter ring

Self-windingTypes of movement

Self-winding is the technical term for automatic winding: the motion of the wrist turns a rotor that winds the mainspring. Swiss and other makers developed it for wristwatches in the 1920s and 1930s, and it became widespread after the Second World War. Today the words 'automatic' and 'self-winding' are used interchangeably.

Also called: automatic winding, auto-winding

See also: Automatic watch, Rotor, Bidirectional winding, Mainspring

Brands: Glycine, Mido, Perrelet, Rolex, Audemars Piguet, Blancpain, Bovet, Breguet

Sellita SW200Movement

The Sellita SW200-1 is a Swiss automatic movement from Sellita in La Chaux-de-Fonds, built to the same dimensions and layout as the ETA 2824-2 and largely compatible with it. It became widely used after ETA reduced deliveries to other brands. In practice the two are similar in quality and serviceability.

Also called: SW200, SW200-1, Sellita SW 200

See also: ETA 2824-2, ETA, Ébauche, Calibre

Brands: Aerowatch, Formex, Gallet

Guide: How much is my watch worth?

Serial numberMarket and collecting

A unique number given to an individual watch case (and sometimes separately to the movement) by the manufacturer. Depending on the brand it is engraved between the lugs, on the rehaut, the caseback or the movement. It helps date a watch, match it to its papers and archive records, and spot problems: a serial number that is missing, re-engraved or not matching the papers is a warning sign.

Also called: serial, case number, S/N

See also: Reference number, Warranty card, Extract from the Archives, Authentication, Rehaut

Guide: Real or fake?

ServiceService and water resistance

Maintenance of a watch by a watchmaker. A full mechanical service usually includes dismantling, cleaning, lubricating and regulating the movement, replacing worn parts and gaskets and testing water resistance; quartz watches mainly need battery changes and seal checks. A recent documented service by the manufacturer or a qualified watchmaker is a plus when selling.

Also called: servicing, watch service, maintenance

See also: Overhaul, Service interval, Service papers, Lubrication, Pressure test

Guide: Watch condition

Service dialDial and hands

A service dial is an original replacement dial supplied by the manufacturer during a service, usually because the old dial was damaged or contained radioactive lume. It is genuine but newer than the watch itself. For vintage collectors a service dial reduces value compared with the original dial; keeping the old dial and handing it over with the watch helps.

Also called: replacement dial, service replacement dial

See also: Redial, Dial, Parts replacement, Service papers

Guide: Watch condition

Service intervalService and water resistance

The recommended time between two services of a watch. For mechanical watches, manufacturers today commonly state around five to ten years, depending on brand, calibre and use. The interval matters because lubricants age; running a watch with dried oils for a long time increases wear and the eventual repair cost.

Also called: service cycle, maintenance interval

See also: Service, Overhaul, Lubrication, Service papers

Brands: Oris

Guide: Watch condition

Service papersService and water resistance

Documents from a watch service: the invoice, a service card or warranty from the manufacturer or watchmaker, often listing the work done and parts replaced. They show when the watch was last serviced and by whom. Recent service papers from the manufacturer are a selling point and also help verify which parts are no longer original.

Also called: service receipt, service card, service history, service record

See also: Service, Service interval, Parts replacement, Box and papers

Brands: Chronoswiss, Aquastar, Armin Strom, Arnold & Son, Baume & Mercier, Bovet, Christophe Claret, De Bethune

Guide: Sell a luxury watch

Setting leverMovement

The setting lever is a small part of the keyless works that moves when you pull the crown out, switching it from winding to date or time setting. It also holds the winding stem in the movement. A worn or broken setting lever causes the crown to fall out or not engage the right position.

Also called: set lever, detent lever

See also: Keyless works, Winding stem, Crown, Hacking seconds

Sharp caseMarket and collecting

A case whose edges, bevels and surfaces still look as they did when the watch left the factory, with crisp lines and full lug thickness. A sharp case may be unpolished or only lightly polished. For vintage and neo-vintage watches it is one of the strongest signs of good condition and can add significantly to the price.

Also called: sharp, crisp case, sharp lugs

See also: Unpolished, Overpolished case, Bevel (chamfer), Honest wear

Brands: Angelus, Patek Philippe

Guide: Watch condition

Shock protectionMovement

Shock protection is a spring-mounted jewel setting that lets the delicate balance staff move slightly and return when the watch is knocked, instead of breaking its pivots. Systems such as Incabloc and KIF became standard in the mid-20th century. Watches with unprotected balances need more care in everyday wear.

Also called: shock absorber, anti-shock system, shockproof

See also: Incabloc, KIF, Balance wheel, Jewel bearing

Brands: Armand Nicolet, Ball Watch, Breguet, West End Watch Co.

Silicon hairspringMovement

A silicon hairspring is made of silicon, often with a silicon oxide layer, produced by etching rather than drawing wire. It is antimagnetic, very light, does not need lubrication and can be shaped precisely. Many brands now use silicon under their own names, such as Patek Philippe's Spiromax or Omega's Si14.

Also called: silicium hairspring, Si hairspring, silicon balance spring

See also: Hairspring, Antimagnetic, Nivarox, Parachrom hairspring, Magnetism

Brands: Mido, Tissot

Skeleton dialDial and hands

A skeleton dial is a dial that is largely cut away or replaced by a ring or frame, revealing the movement beneath. It goes hand in hand with a skeletonised movement, where bridges and plates are also openworked. The effect is decorative and shows off craftsmanship, though legibility often suffers.

Also called: openworked dial, skeletonised dial, open dial

See also: Skeletonisation, Skeleton watch, Chapter ring, Dial

Brands: Romain Gauthier

Skeleton watchTypes of watch

A skeleton watch has a movement whose plates and bridges have been cut away so the mechanism can be seen from the front and back, often with an open or transparent dial. Fine skeletonisation is done by hand and decorated with bevels and engraving, which takes many hours. Machine-cut skeletons are much cheaper. Legibility is usually poorer than with a closed dial.

Also called: skeletonised watch, openworked watch, squelette

See also: Skeletonisation, Skeleton dial, Display caseback, Movement finishing, Anglage

Brands: Arnold & Son, Audemars Piguet, Gerald Charles

Guide: How much is my watch worth?

SkeletonisationMovement

Skeletonisation means cutting away as much material as possible from the plates and bridges so that the inner workings become visible, often combined with engraving and bevelling. Done by hand it is very demanding. Quality varies greatly, from finely finished art pieces to simple machine-cut openings.

Also called: skeletonization, openworking, skeletonising

See also: Skeleton watch, Skeleton dial, Movement finishing, Anglage

Guide: How much is my watch worth?

Slide-rule bezelInstruments and scales

A rotating bezel with a logarithmic scale that works against a fixed scale on the dial like a circular slide rule, allowing pilots to calculate speed, fuel consumption, distance and unit conversions. The best-known example is the Breitling Navitimer, launched in 1952. On vintage pieces, legible, original scales are important for value.

Also called: circular slide rule, navigation computer bezel, logarithmic bezel

See also: E6B, Rotating bezel, Pilot watch, Tachymeter

Brands: Breitling, Ollech & Wajs, Gallet

Guide: How much is my watch worth?

Small secondsDial and hands

Small seconds is a seconds hand in its own subdial, usually at 6 or 9 o'clock, instead of a central seconds hand. It is common on manual-wind dress watches and on chronographs, where the central hand serves the chronograph. Small seconds allow a simpler, often thinner movement layout.

Also called: petite seconde, subsidiary seconds, sub-seconds

See also: Subdial, Manual winding, Dead-beat seconds, Chronograph

Brands: Philippe Dufour, Raymond Weil, Schwarz Etienne

SmartwatchTypes of movement

A smartwatch is a wrist computer with a screen, sensors and apps, connected to a phone. Some Swiss brands, such as TAG Heuer, offer their own models. Smartwatches become technically outdated quickly and depend on software support, so unlike mechanical watches they generally lose value over time and are rarely of interest to collectors.

Also called: connected watch, smart watch

See also: Hybrid watch, Quartz watch, Battery, Wristwatch

Brands: Alpina, Frederique Constant, TAG Heuer

Guide: How much is my watch worth?

Snap-on casebackCase

A snap-on caseback is pressed into the case and held by friction and a small lip, without a thread. It is opened with a knife-like tool at a small notch and closed with a press. It is typical of dress watches, quartz watches and many vintage pieces. It offers less water resistance than a screw-down back.

Also called: snap back, press-fit caseback, pressed caseback

See also: Caseback, Screw-down caseback, Dress watch, Water resistance

Snowflake handsDial and hands

Snowflake hands have a square or rhomboid lume plot near the tip of the hour hand, often matched by square-tipped seconds hands. The design is strongly associated with Tudor dive watches, where it was introduced to improve legibility, and is now used on Tudor heritage models. Original vintage snowflake hands are valuable.

Also called: snowflake, snowflake hand

See also: Mercedes hand, Lume, Dive watch, Patina lume

Brands: Tudor

Guide: Most valuable Swiss watches

Solar watchTypes of movement

A solar watch is a quartz watch that charges a rechargeable cell through a light-sensitive cell, usually beneath a translucent dial. Citizen calls its system Eco-Drive, Seiko uses the name Solar. A full charge typically lasts months. When the storage cell wears out after many years, it has to be replaced.

Also called: light-powered watch, Eco-Drive, solar quartz

See also: Quartz watch, Kinetic watch, Battery, Radio-controlled watch

Solid end linksStraps and bracelets

Solid end links (SEL) are end pieces machined from solid metal instead of being folded or stamped from sheet. They are sturdier, rattle less and fit the case more precisely. In the Rolex world, SEL marks a clear generation change, as earlier bracelets used hollow end links. The term helps to date a bracelet and to check whether it matches the watch.

Also called: SEL, solid endlinks

See also: End links, Hollow links, Folded links, Oyster bracelet

Guide: Real or fake?

Spider dialDial and hands

A spider dial is a vintage dial whose lacquer has developed a fine network of cracks like a spider's web. It results from ageing and from lacquer shrinking over time. Some collectors appreciate a regular, even spider pattern as unique character, while others see it as damage. It cannot be repaired without refinishing the dial.

Also called: spider web dial, crazed dial, cracked lacquer dial

See also: Lacquer dial, Tropical dial, Patina, Redial

Guide: Watch condition

Sports watchTypes of watch

A sports watch is built for an active life: robust case, good water resistance, screw-down crown, luminous markers and a bracelet or rubber strap. The category includes dive, pilot, racing and GMT watches. Steel sports models from leading Swiss brands are among the most sought-after watches on the pre-owned market. Condition, originality and the full set have a big influence on value.

Also called: sport watch, sports model

See also: Luxury sports watch, Tool watch, Dive watch, Racing chronograph, Water resistance

Guide: How much is my watch worth?

Spring barStraps and bracelets

A spring bar is a small spring-loaded metal pin that holds the strap or bracelet between the lugs of a watch case. Its ends fit into holes or recesses in the lugs and are pressed in with a spring-bar tool to remove the strap. Spring bars are cheap wear parts and should be replaced when they weaken, as a failed bar is the most common reason watches fall off the wrist.

Also called: springbar, strap pin, lug bar

See also: Quick-release spring bars, Lug, Lug width, Strap, End links

Spring DriveTypes of movement

Spring Drive is Seiko's name for a movement that is driven by a mainspring like a mechanical watch but regulated by a quartz crystal and an electromagnetic brake instead of an escapement. The seconds hand glides without ticking. It is used mainly in Grand Seiko watches and offers accuracy close to quartz.

Also called: Seiko Spring Drive, Grand Seiko Spring Drive

See also: Mechanical watch, Quartz watch, Hybrid watch, Mainspring

Guide: Swiss watch brands A–Z

Stainless steelMaterials

Stainless steel is the most common case and bracelet material in Swiss watchmaking: an iron alloy with chromium (and usually nickel) that resists rust and takes both brushed and polished finishes well. Most steel watches use 316L; some brands use 904L or their own alloys. On the caseback you will often see "Stainless steel", "Acier inoxydable" or "Inox". Steel itself adds no metal value, so a watch's worth depends on model, condition and demand.

Also called: steel, inox, acier inoxydable, SS

See also: 316L steel, 904L steel, Oystersteel, Titanium, Case

Guide: How much is my watch worth?

Stop-secondsMovement

Stop-seconds is another term for the hacking function: the seconds hand stops while the crown is pulled out for setting. In older literature it can also mean a mechanism that stops the whole movement. Its presence or absence must match the calibre; a vintage watch can legitimately lack it.

Also called: hacking seconds, seconds stop, hack feature

See also: Hacking seconds, Setting lever, Keyless works, Military watch

StrapStraps and bracelets

A strap is a watchband made of a flexible material such as leather, rubber, fabric or silicone, attached to the case with spring bars and usually closed with a tang buckle or a folding clasp. Straps are wear parts and are replaced regularly, so their originality matters much less than that of a bracelet. An original signed buckle, however, is often valued by collectors.

Also called: watch strap, band, watchband

See also: Bracelet, Leather strap, Rubber strap, Tang buckle, Spring bar

SubdialDial and hands

A subdial is a small auxiliary dial within the main dial that displays extra information, such as chronograph minutes and hours, running seconds, a date or a power reserve. Chronographs typically have two or three. The layout of subdials helps identify the movement and model, and their colour can define nicknames such as panda.

Also called: sub-dial, register, counter, totaliser

See also: Chronograph, Small seconds, Panda dial, Dial

Brands: Jaquet Droz

Sunburst dialDial and hands

A sunburst dial has fine lines radiating from the centre, so the dial catches the light and seems to shift in brightness as the watch is turned. It is made by brushing the dial blank before or after colouring. Sunburst finishes are common on modern watches in blue, grey and green; the effect is purely decorative.

Also called: sunray dial, soleil dial, sunray finish

See also: Dial, Guilloché dial, Gloss dial, Matte dial

Super-LumiNovaDial and hands

Super-LumiNova is a non-radioactive luminous pigment based on strontium aluminate, used on most Swiss watches today. It absorbs light and then glows for hours, brightest just after charging. It is produced in Switzerland under licence of the Japanese LumiNova technology and comes in green, blue and other tints. Brands sometimes give it their own names.

Also called: SuperLuminova, SLN, Super Luminova

See also: LumiNova, Lume, Tritium, Relume, Fauxtina

Superlative ChronometerPrecision and certificates

Rolex’s term for its in-house precision standard, printed as “Superlative Chronometer Officially Certified” on the dial. Since 2015 Rolex has tested its cased watches to −2/+2 seconds per day after COSC certification of the movement. The term is specific to Rolex; on vintage Rolex models the dial wording is an important detail when checking originality.

Also called: Superlative Chronometer Officially Certified, SCOC

See also: COSC, Chronometer, Accuracy, Oyster case

Guide: Real or fake?

Swiss lever escapementMovement

The Swiss lever escapement is the form of the lever escapement used in nearly all Swiss and most other mechanical watches today, with club-shaped escape wheel teeth and jewelled pallet stones. Older watches sometimes use the cheaper pin-lever type instead, which is a sign of a low-cost movement.

Also called: Swiss anchor escapement, club-tooth lever escapement

See also: Lever escapement, Escape wheel, Pallet fork, Jewels

Swiss MadePrecision and certificates

A protected designation of origin. Since 2017 a watch may carry it only if its movement is Swiss, it is cased and finally inspected in Switzerland, and at least 60 % of its manufacturing costs arise in Switzerland. It is printed on the dial, usually at the bottom, and on vintage watches its wording and placement are a useful authenticity check, for instance “T Swiss T” on tritium dials.

Also called: Swiss, Swiss-made, Suisse

See also: Swissness ordinance, Swiss movement, Swiss parts, Swiss T 25

Guide: Real or fake?

Swiss movementPrecision and certificates

A legal term for a movement assembled, started up and inspected in Switzerland, with a minimum share of Swiss parts and manufacturing costs set by the Swissness rules. A dial or case marked “Swiss movement” instead of “Swiss Made” usually means only the movement qualifies, while the watch itself was finished elsewhere.

Also called: Swiss mvt, Swiss Movt, Swiss quartz movement

See also: Swiss Made, Swiss parts, Swissness ordinance, Movement

Brands: Glycine, Wenger, Zodiac

Guide: Real or fake?

Swiss partsPrecision and certificates

An inscription meaning that some components, often the movement parts, come from Switzerland, but that the watch was not assembled or finished there. It is not a protected quality mark and does not meet the criteria for “Swiss Made”. On watches presented as Swiss Made, this wording is a reason to look more closely.

Also called: Swiss parts movement, Swiss components

See also: Swiss Made, Swiss movement, Swissness ordinance, Counterfeit watch

Brands: Chronoswiss

Guide: Real or fake?

Swiss T 25Dial and hands

Swiss T 25 is a dial marking found at 6 o'clock on many watches with tritium lume from the later tritium era. It means the watch is Swiss made and contains no more than 25 millicuries of tritium. Earlier tritium dials often show T Swiss T or Swiss – T. The marking helps date a dial and identify the lume type.

Also called: T Swiss T, Swiss T<25, T 25, T<25

See also: Tritium, LumiNova, Swiss Made, Lume

Swissness ordinancePrecision and certificates

The Swiss federal rules defining when a watch may be called “Swiss Made”. The revised ordinance in force since 1 January 2017 requires, among other things, that at least 60 % of manufacturing costs arise in Switzerland and that the technical development take place there. Watches made before 2017 followed the older, less strict rules.

Also called: Swissness rules, Swiss Made ordinance, Swissness

See also: Swiss Made, Swiss movement, Swiss parts, Manufacture

Guide: Real or fake?

Sword handsDial and hands

Sword hands are shaped like a sword blade, broad near the centre and tapering to a point. They are often filled with lume, giving good legibility, and are common on dive, pilot and field watches. Their simple, functional shape suits both sports and dress styles.

Also called: sword-shaped hands, glaive hands

See also: Leaf hands, Baton hands, Lume, Field watch

T

TachymeterComplications

A scale, printed on the dial edge or bezel, used with a chronograph to measure speed: start the chronograph at a marker, stop it after a known distance (usually one kilometre or one mile), and the seconds hand points to the average speed in units per hour. It only works for times under one minute. The style of the scale is an important detail when checking whether a vintage dial or bezel is original.

Also called: tachymetre, tachometer scale, tachy

See also: Tachymeter bezel, Chronograph, Telemeter, Racing chronograph

Brands: Angelus

Guide: How much is my watch worth?

Tachymeter bezelInstruments and scales

A bezel engraved or printed with a tachymeter scale, as opposed to a scale on the dial edge. It is a classic feature of racing chronographs such as the Omega Speedmaster and many Rolex Daytona models. On vintage watches the bezel type, font and any damage are important for value, since replaced bezels are common.

Also called: tachy bezel, tachymetre bezel

See also: Tachymeter, Chronograph, Racing chronograph, Bezel

Guide: How much is my watch worth?

Tang buckleStraps and bracelets

A tang buckle is the traditional pin buckle used on straps: a metal frame with a pin (tang) that passes through a hole in the strap, like a belt. It is simple, light and the original closure on most leather straps. Original buckles signed with the brand's logo are collectible, and a missing or non-original buckle is a small but real detail in valuing vintage watches.

Also called: pin buckle, ardillon buckle, tongue buckle

See also: Deployant clasp, Strap, Leather strap, Full set

Tank watchTypes of watch

The Tank is Cartier's rectangular watch with strong vertical sidebars (brancards) that continue the line of the lugs, designed by Louis Cartier in 1917 and said to be inspired by the outline of tanks. It became one of the defining rectangular watches, made in many variations. "Tank" is Cartier's model name; other brands' rectangular watches with similar cases are only "tank-style".

Also called: Cartier Tank, Tank Louis Cartier, tank-style watch

See also: Dress watch, Roman numerals, Case, Reversible case watch

Guide: Swiss watch brands A–Z

TantalumMaterials

Tantalum is a rare, very dense blue-grey metal that is highly corrosion-resistant and hypoallergenic. It is extremely difficult to machine and polish, so it appears only in small numbers of high-end or limited watches, sometimes combined with gold or titanium. A tantalum case feels heavier than steel and has a darker, slightly bluish tone. It is not a precious metal, but its rarity can make such pieces interesting to collectors.

Also called: Ta

See also: Titanium, Platinum, Stainless steel, Limited edition

Guide: Most valuable Swiss watches

TelemeterComplications

A chronograph scale that measures distance using the speed of sound: start the chronograph when you see an event such as lightning or a gun flash, stop it when you hear it, and read the distance on the scale. It is often printed in a spiral or around the dial edge and was popular on chronographs of the first half of the 20th century.

Also called: telemetre, telemetric scale

See also: Chronograph, Tachymeter, Pulsometer, Decimal scale

Brands: Angelus

Guide: Most valuable Swiss watches

Thermocompensated quartzTypes of movement

A thermocompensated quartz movement measures temperature and corrects the frequency of its crystal accordingly, because temperature is the main source of quartz error. Such movements can reach accuracy of a few seconds per year. Examples include Breitling's SuperQuartz and Grand Seiko's 9F; many COSC-certified quartz watches use this technology.

Also called: HAQ, high-accuracy quartz, TCXO, thermo-compensated quartz

See also: Quartz watch, COSC, Accuracy, Chronometer

Tide indicatorComplications

A display showing the state of the tides, high or low, usually derived from the moon’s position since the tides follow the lunar cycle. It must be set for a particular location and gives only an approximate reading. It is found on sailing and astronomical watches.

Also called: tide display, marées, tide phase

See also: Moon phase, Astronomical complication, Regatta timer, Complication

Guide: How much is my watch worth?

TimegrapherPrecision and certificates

An electronic instrument that listens to a watch’s ticking through a microphone and displays its rate in seconds per day, the amplitude and the beat error. It allows quick assessment of a mechanical movement’s condition without opening the case. Readings depend on position and state of wind, so several positions should be checked.

Also called: timing machine, watch timing machine, Witschi

See also: Amplitude, Beat error, Seconds per day, Regulation, Accuracy

Guide: Watch condition

TitaniumMaterials

Titanium is a light, strong, corrosion-resistant metal used for sports and tool watches. A titanium case weighs roughly 40 % less than an equivalent steel case and is warm to the touch, with a slightly greyer, duller colour than steel. Pure (grade 2) titanium scratches fairly easily; grade 5 alloy is harder and polishes better. Titanium is also hypoallergenic, which makes it popular with wearers sensitive to nickel.

Also called: Ti, grade 2 titanium, commercially pure titanium

See also: Grade 5 titanium, Stainless steel, Tantalum, DLC coating, Tool watch

Brands: De Bethune, Hublot, IWC Schaffhausen, Kross Studio, Richard Mille, Simon Brette, Tudor, Adriatica

Tonneau caseCase

A tonneau case is shaped like a barrel: longer than wide, with curved sides that are wider in the middle than at the ends. The French word means barrel. It was popular in the Art Deco period and was revived by several modern haute horlogerie brands. Shaped cases often need specially shaped movements.

Also called: barrel-shaped case, tonneau

See also: Case, Cushion case, Tank watch, Dress watch

Brands: Franck Muller

Tool watchTypes of watch

A tool watch is a watch built primarily for a practical purpose – diving, flying, racing, exploring or working in strong magnetic fields – with function taking priority over decoration. Typical traits are robustness, legibility, water resistance and practical bezels or complications. Many of today's most collected sports watches started as tool watches. Honest wear from use is accepted more readily on them than on dress watches.

Also called: instrument watch, professional watch

See also: Sports watch, Dive watch, Pilot watch, Field watch, Antimagnetic

Guide: How much is my watch worth?

TourbillonComplications

A mechanism in which the balance and escapement sit in a rotating cage, usually turning once a minute, so that errors caused by gravity in vertical positions are averaged out. Abraham-Louis Breguet patented it in 1801. In a wristwatch it is today mainly a showcase of craftsmanship; it is usually visible through a dial opening and has a strong effect on price.

Also called: tourbillon regulator, whirlwind

See also: Flying tourbillon, Multi-axis tourbillon, Carrousel, Escapement, Positional error

Brands: Kross Studio, Greubel Forsey, F.P. Journe, Richard Mille, Haldimann, Purnell, Biver, Cyrus Genève

Guide: Most valuable Swiss watches

Trench watchTypes of watch

A trench watch is an early wristwatch from around the First World War, often a small pocket-watch movement in a round case with wire lugs soldered on for a strap. Many have enamel or porcelain dials, radium lume and a shrapnel guard – a pierced metal cover over the crystal. They mark the transition from pocket watches to wristwatches. Original lume and dials affect value; radium markings should not be handled carelessly.

Also called: wire-lug watch, officer's watch, WWI wristwatch

See also: Wristwatch, Pocket watch, Military watch, Radium, Enamel dial

Guide: How much is my watch worth?

Triple calendarComplications

A calendar display showing date, day of the week and month. Like a complete calendar, it does not know the length of each month, so the date must be corrected by hand at the end of short months. When a moon phase is added, the watch is usually called a triple calendar moon phase or a complete calendar.

Also called: triple date, day-date-month

See also: Complete calendar, Annual calendar, Moon phase, Day-date display

Guide: How much is my watch worth?

TritiumDial and hands

Tritium is a radioactive form of hydrogen that was mixed into luminous paint on watch dials and hands for several decades until the late 1990s. It glowed without charging, but its half-life of about 12 years means old tritium lume no longer shines. Dials with tritium are often marked with a T on the dial. Aged tritium develops colours from cream to brown, prized by collectors.

Also called: tritium lume, H3

See also: Swiss T 25, Radium, Lume, Patina lume, LumiNova

Brands: Traser, Ball Watch, HYT, Luminox

Tropic strapStraps and bracelets

A Tropic strap is a rubber dive strap with a basket-weave pattern on top, first made in the 1960s and fitted to dive watches of that era. It was designed to stay supple in warm water and to let the skin breathe through small perforations. Original vintage Tropic straps are fragile and collectible; modern reproductions are widely available.

Also called: Tropic rubber strap, Tropic band

See also: Rubber strap, Dive watch, Vintage, Strap

Tropical dialDial and hands

A tropical dial is a dial, usually originally black, that has turned brown or chocolate over the decades through exposure to sunlight and the instability of some early paints. Each tropical dial is unique. When the change is even and natural, collectors may pay a premium. Artificial ageing exists, so the provenance and consistency of the colour matter.

Also called: tropical, brown dial, chocolate dial

See also: Patina, Dial, Redial, Vintage, Provenance

Guide: Most valuable Swiss watches

Tuning fork watchTypes of movement

A tuning fork watch uses a small electrically driven metal tuning fork as its oscillator, producing a humming sound and a perfectly smooth seconds hand. The best-known is the Bulova Accutron, launched in 1960. It was soon overtaken by quartz, and today tuning fork watches are collected as an interesting technical chapter.

Also called: Accutron, tuning-fork movement

See also: Electric watch, Quartz watch, Quartz crisis, Vintage

Guide: Most valuable Swiss watches

Tuxedo dialDial and hands

A tuxedo dial is a two-tone dial, usually with a light centre and a black outer ring, or the reverse, recalling the contrast of a tuxedo. The term is used mainly for vintage dress and chronograph watches. It is a collectors' nickname rather than an official brand term. Faded or uneven colour on old tuxedo dials should be checked for refinishing.

Also called: two-tone dial, bicolour dial

See also: Dial, Sector dial, Panda dial, Vintage

Twin barrelMovement

A twin-barrel movement has two mainspring barrels, linked in series for a longer power reserve or in parallel for more even torque. It is a feature of more elaborate movements and is often mentioned in specifications. You cannot see it from outside, but it explains why some watches run for several days on a full wind.

Also called: double barrel, two barrels

See also: Barrel, Power reserve, Mainspring, Power reserve indicator

Brands: Simon Brette

Two-toneMaterials

Two-tone describes a watch that combines two metals, most often stainless steel with yellow or rose gold – typically a gold bezel and crown with gold centre links on a steel bracelet. Rolex calls this combination Rolesor. The gold parts are usually solid 18k, but cheaper watches may use gold plating instead. Check which parts are solid gold, as this strongly affects value and how wear can be repaired.

Also called: bicolor, bi-colour, steel and gold, Rolesor, tutone

See also: Stainless steel, Yellow gold, Rose gold, Gold-plated, Jubilee bracelet

Guide: How much is my watch worth?

U

Unidirectional bezelCase

A unidirectional bezel turns in one direction only, normally anticlockwise, and clicks into place at each step. It is standard on dive watches: if it is knocked accidentally it can only show a longer elapsed time, never a shorter one, so a diver will not overstay underwater. A worn ratchet or a bezel that turns both ways points to wear or non-original parts.

Also called: uni-directional bezel, one-way bezel, ratcheting bezel

See also: Rotating bezel, Count-up bezel, Dive watch, ISO 6425, Bidirectional bezel

Unitas 6497Movement

The Unitas 6497 is a large hand-wound Swiss movement originally designed for pocket watches, now made by ETA, running at 18,000 vph. It has small seconds at 9 o'clock; its sister, the 6498, has them at 6. Its size and robustness make it popular for big wristwatches and display-back models.

Also called: 6497, ETA 6497, Unitas 6498, 6498

See also: ETA, Manual winding, Pocket watch, Small seconds

Brands: Aerowatch, Auguste Reymond, Epos

UnpolishedMarket and collecting

Describes a case and bracelet that have never been polished, so the original finish, edges and surfaces are intact, even if they show scratches. Collectors often prefer an unpolished watch with honest wear to a polished one. The claim is hard to prove; experts look at the original brushing pattern, the sharpness of the bevels and the depth of engravings.

Also called: never polished, unpolished case

See also: Sharp case, Overpolished case, Honest wear, Brushed finish

Brands: Glycine, Omega, Rolex, Titoni, Urwerk, Alpina, Gallet, Gérald Genta

Guide: Watch condition

UnwornMarket and collecting

A watch that has been sold at least once but never actually worn, ideally with protective stickers still in place and no marks on case or clasp. Unworn watches are often sold on the secondary market shortly after purchase and fetch prices close to or above new. The claim should be checked: tiny scratches on the clasp or caseback show the watch has been worn.

Also called: new unworn, brand new, stickered

See also: New old stock (NOS), Pre-owned, Full set, Grey market

Brands: Swatch

Guide: Watch condition

V

Valjoux 7750Movement

The Valjoux 7750 is an automatic chronograph movement introduced in 1974, now made by ETA. It uses a cam-actuated system and typically shows 30-minute and 12-hour counters plus small seconds. Robust and easy to service, it is found in a great many chronographs of different brands and price levels.

Also called: 7750, ETA 7750

See also: ETA, Chronograph, Cam-actuated chronograph, Ébauche

Brands: Aerowatch, Maurice de Mauriac, Louis Erard, Ollech & Wajs

Guide: How much is my watch worth?

Vertical clutchMovement

A vertical clutch connects the chronograph to the running movement with a friction clutch stacked along the same axis, instead of meshing gears sideways. This avoids the seconds hand jumping at start and allows the chronograph to run continuously without extra wear. Examples include Rolex's calibre 4130 and Frédéric Piguet's 1185.

Also called: vertical coupling, friction clutch

See also: Horizontal clutch, Column wheel, Chronograph, Cam-actuated chronograph

Vibrations per hourMovement

Vibrations per hour (vph) counts the single swings of the balance in one hour; each full oscillation consists of two vibrations. 28,800 vph equals 4 Hz, 21,600 vph equals 3 Hz and 18,000 vph equals 2.5 Hz. The figure appears in movement specifications and tells you roughly how a calibre behaves and how smooth its seconds hand sweeps.

Also called: vph, A/h, alternations per hour, bph

See also: Frequency, Beat rate, Balance wheel, Timegrapher

Brands: Zenith, Girard-Perregaux, Kross Studio, Louis Moinet, Simon Brette

VintageMarket and collecting

A term for older watches, usually understood as roughly 30 years or more, though there is no fixed definition. For vintage watches, originality matters most: original dial, hands, crown and case shape with little polishing are worth far more than restored pieces. Signs of age such as patina are accepted or even desired, while replaced or refinished parts lower the value.

Also called: vintage watch, antique watch

See also: Neo-vintage, Patina, Service dial, Unpolished, Franken watch

Guide: How much is my watch worth?

W

Waiting listMarket and collecting

An informal or formal queue at an authorised dealer or boutique for watches that are in short supply. Dealers usually decide who gets a watch themselves and may favour clients with a purchase history, so a place on the list is no guarantee. Long waiting lists are one reason why certain models trade above retail price on the secondary market.

Also called: waitlist, wait list

See also: Authorised dealer (AD), Hype watch, Retail price, Grey market

Guide: Most valuable Swiss watches

Wandering hoursComplications

A display in which hour numerals mounted on rotating satellites travel along a minute arc; the current hour’s numeral points to the minutes as it moves across. Known in French as “heures vagabondes”, it goes back to 17th-century clocks and is used today by brands such as Audemars Piguet and Urwerk.

Also called: satellite hours, heures vagabondes, wandering hour

See also: Jumping hour, Retrograde display, Regulator dial, Complication

Brands: Urwerk

Guide: Most valuable Swiss watches

Warranty cardMarket and collecting

The document issued by the authorised dealer when a new watch is sold, showing the model, serial number, date of purchase and dealer stamp; modern versions are often plastic cards or digital. Older ones are paper certificates or booklets. A matching, correctly filled-in card is a key part of a full set, but cards are also faked, so the details should agree with the watch itself.

Also called: guarantee card, warranty certificate, papers, guarantee

See also: Box and papers, Full set, Authorised dealer (AD), Serial number, Authentication

Guide: Real or fake?

Watch appraisalMarket and collecting

A professional assessment of a watch's value, usually written, stating the watch's details, condition and the value for a particular purpose such as insurance, inheritance or sale. Its value basis (replacement, market or auction value) should be stated. An appraisal is not the same as an authentication; it builds on the watch's identity, but certifies a value, not genuineness.

Also called: valuation, appraisal, watch valuation

See also: Estimate, Authentication, Reference number, Investment watch

Guide: Watch appraisal

Water resistanceService and water resistance

A watch's ability to keep water out up to a stated pressure, given in metres, atm or bar. The figure is a test pressure, not a safe diving depth; a watch marked 30 m is only splash-proof in practice. Water resistance depends on intact gaskets, crown and crystal and decreases with age, so it should be tested regularly, especially before swimming.

Also called: water resistant, WR, waterproof

See also: ATM, Bar, Pressure test, Gasket, Screw-down crown

Brands: Delma, Mido, Revue Thommen, Rolex, Alpina, Auguste Reymond, Certina, Edox

Guide: Watch condition

White goldMaterials

White gold is gold alloyed with whitening metals such as palladium or nickel, giving a pale colour similar to steel or platinum. In watches it is usually 18k (750) and is often rhodium-plated for a brighter white; that plating can wear through over time and show a slightly yellowish tone. Because it looks like steel, a white gold watch can be mistaken for a much cheaper piece – check the hallmarks and the weight.

Also called: 18k white gold, WG, white gold 750

See also: Gold, 18k gold, Platinum, Palladium, Precious metal hallmark

Brands: Genus, Philippe Dufour

Guide: How much is my watch worth?

Winding stemMovement

The winding stem is the thin steel rod that connects the crown to the movement. Turning it winds the mainspring or sets the hands, depending on its position. Stems are specific to a calibre; a replacement stem that is too short or crudely cut can hint at a non-original movement or careless repair.

Also called: stem, crown stem

See also: Keyless works, Crown, Setting lever, Aftermarket parts

Guide: Real or fake?

World timerComplications

A watch that shows the time in all 24 main time zones at once, using a ring of city names and a rotating 24-hour ring. Set it once for your home city and you can read the hour anywhere by looking at the city in question. Vintage world timers, especially early ones with enamel dials, are among the most valuable complicated wristwatches.

Also called: world time, heures universelles, worldtimer

See also: GMT, Dual time, 24-hour bezel, Complication

Brands: Frederique Constant, Andersen Genève, Arnold & Son, Edox, Alpina, Concord, Oris, Patek Philippe

Guide: Most valuable Swiss watches

WristwatchTypes of watch

A wristwatch is a watch designed to be worn on the wrist with a strap or bracelet, as opposed to a pocket watch. Early wristwatches were mostly made for women, while men began wearing them widely during and after the First World War. Today the term covers everything from simple time-only pieces to grand complications. Value depends on brand, reference, movement, condition and originality.

Also called: wrist watch, wristlet

See also: Pocket watch, Trench watch, Ladies' watch, Dress watch

Guide: How much is my watch worth?

Y

Yellow goldMaterials

Yellow gold is the traditional gold colour, made by alloying pure gold with roughly equal parts silver and copper. Swiss watches use 18k (750) yellow gold; older or American pieces may be 14k (585). It is softer than steel and shows scratches and dents, so heavy polishing and worn edges are common on vintage yellow gold cases and affect value. Always check the hallmarks to rule out plating or gold-filled cases.

Also called: YG, 18k yellow gold, 750 yellow gold

See also: Gold, 18k gold, Rose gold, Gold-plated, Gold-filled

Brands: Daniel Roth, Singer Reimagined

Guide: How much is my watch worth?