Alarm
A watch provided with a movement capable of releasing an acoustic sound at a preset time. Most often, a second crown is present dedicated to winding, setting, and releasing the alarm while an additional hand is present on analog dials in order to display when the alarm chime should sound. On digital watches, this alarm time is often shown in a separate display function.

Ana-Digital
A watch with both an analog and digital display. The analog display has a traditional dial with hour, minute and, sometimes, second hands while the digital display shows the time numerically with an liquid-crystal display (see LCD).

Analogue/Analog
A watch that displays the time by means of hands.

Applique/Applied
Numerals or symbols cut out of a sheet metal and stuck or riveted to a dial.

Anti-reflective
Superficial glass or crystal treated to disperse reflected light. Often, to avoid scratching, only the inner surface of the crystal is treated.

ATM
Used to express the water resistance of a watch. An abbriation for “atmosphere”, it’s equal to approximately 10 meters of water pressure. Another word for atmosphere is “bar,” which is often used in Europe.

Automatic Watch
A watch whose mechanical movement is wound by the movements or accelerations of the wearer's arm. The rotor turns and transmits its energy to the spring by means of an appropriate mechanism. The system was invented in Switzerland by Abraham-Louis Perrelet in the 18th century.

Balance
Oscillating device that along with the balance spring makes up the heart of a watch movement. The hairspring coupled to it makes it swing to and fro, dividing time into exactly equal parts. Each of the to-and-fro movements of the balance (“tick-tack”) is called an “oscillation”. One oscillation is composed of two vibrations.

Balance Spring
This narrow, ribbon-shaped strip of steel alloy metal (see Nivarox) helps to ensure that the balance swings to and fro at a precise rate. Lengthening or shortening the balance spring alters the duration of the balance's beats. An alternative name for the “hairspring”, the term “balance-spring” is preferred in the United States but is not unknown in Britain as it’s regarded by some English writers as ‘colloquial’ but certainly established in mid-19th-century British usage.

Barrel
A thin, cylindrical box containing the mainspring of a watch. The toothed rim of the barrel meshes with pinion of the train. Inside this box, the mainspring is wound around an arbor and then turned by means of the winding crown and/or the rotor.

Bearings
Holes drilled to accept the pivots of the gear-train. In fine wristwatches and pocket-watches, as well as in larger clocks, the bearings are specially fitted with jewels to minimize the friction encountered by the pivots of rapidly turning organs such as wheels and pinions. Simple (and simpler) timepieces make do with simple holes drilled into the plates, bridges or cocks. Over time and lacking adequate lubrication, these holes can widen. In this case, watchmakers who are capable, willing and properly trained can install brass or bronze settings.

 

Bezel
The top part of the case that can hold the crystal. The bezel can either be integrated the case middle or a separate element. It can either be snapped or screwed in around the dial.

Bracelet
A metal band attached to the case. Often called “integral” if there’s no apparent discontinuity between the case and bracelet.

Bridge
The structural element of a movement that supports the wheel train, balance, escapement, and barrel. Each bridge is fastened to the plate by means of screws and locked into specific positions by pins. Often in high quality movements, these bridges are finished with various finishes and/or decoration.

Brushing/Brushed Finish
A topical finish giving the metals of cases, bracelets, and buckles a clean matte look.

Cabochon
This term is often used to indicate a smooth round or oval convex shaped polished gemstone. In watch terminology, it describes a decorative stone set within the watch crown.

Calendar
A many watches, this function indicates the date of the month. Other watches also offer the month, day of the week and/or the year as well.

Caliber
Initially used to indicate the size of a watch movement, this term now denotes a type and/or shape of a movement (round caliber, automatic caliber, etc). It combines the manufacturer's mark and identification number to serve as an indication of origin.

Carat
A carat is the term used to describe the weight of any gemstone, including diamonds. Although the definition of a carat has changed over time, since 1913 the international standard has been 200 milligrams, or 1/5 of a gram. Often, jewelers describe carats in 1/4 increments.

In jewelry pieces with more than one diamond, the carats may be described in terms of carat total weight (CTTW). This is the combined total weight of all the stones in the piece.

Carriage
The rotating frame of a tourbillon, carrying the balance and escapement. This frame is essential to establish perfect balance and stability of the complete tourbillon system, no matter the weight of its components. Many modern carriages rotate once per minute, hence eliminating any error due to positioning.

Case
Container to which the watch-movement sits within and protects it from dust, dampness and shocks. The appearance of an individual watch case can vary dramatically depending on current fashion and/or the taste of the watch manufacturer producing it.

Champlevé/Cloisonne
A hand made treatment often used for watch dials and/or cases in which a metal sheet is hollow-patterned with a graver and then filled with enamel. Chamfering/Beveling Chamfered edges on the steel parts are characteristic of the finest watches. Chamfering is performed either mechanically with a pantograph or traditionally by hand with a file along the part's edge. The angle of a chamfer is typically 45 degrees.

 

Chronograph
Watch or other apparatus with two independent time systems: one indicates the time of day, and the other measures brief intervals of time. Counters registering seconds, minutes and even hours can be started and stopped as desired. It is therefore possible to measure the exact duration of a phenomenon. Not to be confused with a chronometer.

Chronometer
According to Swiss law, a watch must undergo series of precision tests in an official institute before it can be certified and use the word, “chronometer” on the model. One of many precision requirements include maintaining time within a few seconds per day even in the most unfavorable temperature conditions (for mechanical watches) and various positions that are ordinarily encountered.

Circular graining
See Pearlage

Column Wheel
Part of a chronograph movement that controls the functions of various levers and other parts inside. Shaped into a small-toothed steel cylinder, it is controlled by push buttons that hold and release it.

Corrector
See Push Button

Côtes de Genève
A decoration applied to high quality movements, appearing as a series of parallel ribs. These ribsare created by means of repeated, grooved cuts with thin stripes in-between.

Counter
The additional stopwatch hand on a chronograph indicating the time elapsed. On many chronographs, the seconds counter hand is set in the center with minute and/or hour counter subsidiary dials.

Crown
Small round serrated knob typically located at the 3 o'clock position. It is used as a winder, hand setter, and often also to set the date or a secondary time zone. For waterproofing purposes, some watches use a “screw-down crown” which screws in against the case to provide extra protection for the movement.

Day/Night
A function often displayed in a half-circle window on a dial. A small disc with a sun on one side and a crescent moon on the other rotates gradually with the main hour and minute hands. This is generally a function to distinguish between AM and PM hours.

Dial
Indicating “face” or plate of metal or other material, bearing various markings to show, in ordinary watches and clocks, the hours, minutes and seconds. Dials vary very much in shape, decoration, material, etc. The indications are given by means of numerals, divisions or symbols of various types.

Digital Watch
See LCD

Diver’s Buckle
A buckle often attached to a bracelet that secures the two ends together by means of a three piece folding enclosure. Two folds sit underneath the bracelet while a third clasps on top of a snap-tight or push button buckle.

Ébauche
French term (but commonly used in English-speaking countries) for a movement blank, i.e. an incomplete watch movement which is sold as a set of loose parts, comprising the main plate, the bridges, the train, the winding and setting mechanism and the regulator. The timing system, the escapement and the mainspring, however, are not parts of the ébauche.

 

Electroplating/Plating
The process of covering metal with the film of other metals. The base metal is immersed in a chemical solution, and then electrical current flows through the solution from another piece of metal to the base metal, therefore depositing the finish of the second metal on top of the first through electrolysis. Most common metals used for plating include: gold, silver, chromium (chrome), palladium, rhodium and ruthenium. This plating is generally measured in thickness the term, “microns”. A higher micron rating generally means a thicker layer of plating. Also referred to as PVD (Physical Vapor Deposition) plating.

Escapement
Positioned between the train and the balance wheel, this mechanism governs the rotation speed of the wheel-train. An essential piece of any automatic watch movement, the most popular version of the escapement used today involves a lever that ticks to and fro against the balance wheel.

Fly-back Hand
In a chronograph with analogue display, an additional centre second hand which can remain superposed on the other one as it moves, can be stopped independently and then made to “fly back” so as to catch up with the other hand, can be stopped and reset to zero together with the other hand.

Fold-over clasp
A hinged buckle that allows for easy fastening to the case. Two pieces fold under the band to provide a flat surface while held in place with either a snap or push button buckle.

Gasket
A rubber or plastic ring that seals and protects the internal works of the watch against dust, moisture and water.

GMT
See World Time

Glucydur balance
After the invention of self-compensating balance-springs, the glucydur balance replaced the bimetallic compensating balance. It is made from an alloy of copper which contains approximately 3 percent beryllium, the admixture of which gives the metal a golden hue. The simpler nickel balances are silver in color. It has a hardness of 380 Vickers, compared to 220 Vickers for a nickel balance and 180 Vickers for a brass balance. Thanks to its greater hardness, the glucydur balance can be excellently riveted, poised and finely regulated and is immune to oxidation.

Guilloché
A decoration often used on watch dials consisting of engraved patterns – often crossing or interlacing lines – either done by hand or engine. Dials are often decorated this way with metallic finishes to further expose the patterns.

Hand
An indicator, usually made of a thin piece of metal which moves over a analog time display to visualize hours, minutes, seconds as well as other functions. Generally made of plated brass, a watch hand can be carved into many different styles & shapes if only to add to the overall appearance of a watch.

Helium Escape
Valve During deep-sea dives lasting several days, divers operate from diving bells. Prior to surfacing, these bells are filled with a mixture of helium and oxygen. The helium molecules are lighter than air and can therefore penetrate the watch in sufficient quantity to push out the crystal at atmospheric pressure levels. This can be avoided by opening the valve during resurfacing, which allows the helium to escape but prevents water from entering the watch.

Incabloc
This term is often associated with shock absorption for pocket-watches and wristwatches, and can be readily integrated into all calibers. (see Shock-Resistant)

Indirect central second-hand
On watch-movements with an indirect central second-hand, the impulse which propels the second-hand lies outside the actual flow of energy in the gear-train. It is often found on calibers which are constructed with a small second subsidiary dial.

 

Jewels
The “jewels” of a watch refer to the synthetic rubies resting inside the movement that allow steel pivots to turn high wear parts such as the wheel train and the escape lever. The jewel’s hardness reduces wear on watch for anywhere between 50 to 100 years. The quality of the watch is determined by the shape and finishing of the jewels rather than the amount used.

Jeweler’s Clasp
A closure most common on women’s watch bracelets, this clasp slips around a small bar and snaps into place in order to lie flat.

Jump Hour
A watch-movement in which the hour-hand has been replaced by a separate display (either a subsidiary dial or a display window) with the twelve numerals that correspond to the hours. A small additional mechanism ensures that the hour indicator jumps ahead 30º at the conclusion of each successive 60-minute interval.

K1 Hardened Crystal
A K1 crystal is a mineral crystal that has been specifically hardened so that it has a smoother texture. This is often done do that the crystal can lie flush with its corresponding watch case and therefore be more difficult to damage.

Karat
A unit of measurement specifying the amount of gold in an alloy. The karat scale ranges from zero to 24. Fine gold, which is nearly 100% pure, is described as 24 karat. The case of an 18-karat gold wristwatch has 750 parts per thousand of fine gold, together with various other metals mixed into the alloy (e.g. copper, brass, silver, etc.). A karat is also a unit of weight: one karat is 1/24th of a kilogram of fine gold, or 41.66 grams. The purity of the gold alloy is generally stamped onto the back the case.

Kinetic Quartz
Very similar to an automatic watch except that it contains quartz technology. An exclusive design for Seiko Instruments, a Kinetic quartz generates electrical energy to power itself from the natural movement of the wearer’s arm and wrist.

Liquid Crystal Display (LCD)
A digital display where the numbers are formed in a liquid layer sandwiched between a pair of clear crystals. A common term used with digital watches.

Lever Escapement
This is a escapement that operates by means of an anchor with pallets; invented ca. 1715 by English watchmaker G. Graham. Types of lever escapements include: English lever escapement, Glashütte escapement, and Swiss lever escapement.

Lubrication
This is commonly done to reduce friction caused by the constant movement of wheels and other parts within a watch movement. Common points to be lubricated include the jewels, between levers, and the spring inside the barrel. It’s advised that you have your watch’s automatic movement lubricated every 2-3 years to ensure proper operation.

Lug Screw
A double extension bar that attaches the case to the band. Often these are stylized to look like large screws on either side. Normally cases and straps are attached with a removable spring bar.

Luminous/Luminescent
The material often applied to hands and/or hour markers that displays a luminous energy previously absorbed as electromagnetic rays.

Luminous dials began production around 1910 using Radium. It wasn’t until the 1950’s and 60’s that the radioactive dangers of radium were fully understood and this substance was replaced with Tritium. In the last few years, Tritium has been replaced with substances that emit little to no radioactivity such as Lumibrite and Super-LumiNova.

Mainspring
The driving spring of a watch or clock contained in the barrel that stores and transmits the power force needed for functioning.

Markers
Elements printed or applied on the dial (sometimes luminous) that are used as reference points for the hands to indicate hours and minutes.

Mechanical Watch
A timepiece which is powered by a mainspring and whose oscillating system runs on a purely mechanical basis, e.g. balance or pendulum. Also known as a 'Manual Wind' watch.

Mineral crystal
This is the type of glass which contains minerals and is used for most watch crystals. It is harder (5 on the Mohs scale) and thus more resistant to scratches than artificial glass (e.g. Plexiglas), however is it not quite as resistant as a sapphire crystal. Some watch manufacturers use crystals made of mineral covered with a layer of synthetic sapphire (a Mohs rating of 6-7). Seiko Watchmakers often call this composite material “Sapphlex”

Moon-Phase
A function available on some watches, usually combined with calendar-related features. The moon-phase disc advances one tooth every 24 hours upon a wheel of 59 teeth that assures almost perfect synchronization with the lunar cycle. One cycle is approximately equal to 29.53 days. However, the difference of approximately 44 minutes each month implies that the phase will need to be manually adjusted back into sync approximately every 2 and a half years.

Movement
The assembly consisting of the principal elements and mechanisms of a watch or clock. Movements in modern times are divided into two groups: quartz and automatic.

Nivarox
The trade name (named for the founder) for a special steel alloy used for self-compensating balance springs. This material resists magnetization and often indicated in quality level in decreasing value from 1 to 5.

Oscillation
Two half-oscillations produce the familiar “tick-tock” of a mechanical watch. Together, two beats/vibrations comprise one oscillation.

Pearlage
A superficial decoration applied to bridges, rotors, and pillar plates in the shape of numerous superposed circles, typically made with a plain cutter and abrasives.

Perpetual calendar
A complex horology complication, this calendar feature indicates the day, date, month, and leap year without the need for manual correction until the year 2100.

Plexiglas
A low-cost, synthetic resin often used for watch crystals.

Poinçon de Genève
A distinction assigned by the Canton of Geneva to movements produced by watchmaker firms of the region that comply with all standards of high horology with respect to craftsmanship, small-scale production, working quality, accurate assembly and setting. A Geneva seal is then engraved on at least one bridge of the movement to display this grand distinction.

Power Reserve
The power reserve is the maximum interval during which a mechanical movement continues to run after its mainspring has been fully wound. Some modern timepieces include a dial function that keeps track of how much power remains within the movement.

Precision
The ticking timepiece numbers among the oldest and most precise mechanical machines. A movement which deviates from the official norm time by 30 seconds per day (one day = 86,400 seconds) performs with an arithmetical error of merely 0.035%. In other words, its precision is 99.965%. Officially certified chronometers achieve far higher levels of precision and may deviate from perfect performance by less than 0.005%.

Push Button
A component which activates or deactivates a particular function. On many chronographs, the stopwatch functions are activated by means of a push button. Also on many multi-function watches, the functions are adjusted with these buttons.

Regulating
Unit Made up of the balance and balance spring, this mechanism governs the accurate division of time within a movement. The balance works like a mini pendulum while the spring helps it shift to the next oscillation. These actions combined determine the vibrations per hour that many automatic watches speak about.

Repeater
Mechanism indicating time with acoustic sounds. Often provided with two hammers and two gongs, the repeater chimes approximately every 15 minutes. The mechanism that makes sure each chime occurs at specific times is one of the most complex movement enhancements available for watches.

Retrograde/Flyback
This is a general term for a hand that moves in an arc scale of 90° to 180° instead of the normal 360°. Once this hand reaches the end of its arc, it jumps back instantaneously to the beginning once more. Normally retrograde or “flyback” functions such as this are used for date, day, month, and even minutes and seconds on some more complicated watches.

Rotor
On the back of many automatic movements, the rotor is the large half-circle of metal that winds the watch in complete or partial revolutions as its wearer moves his or her arm. This motion allows for the winding of the mainspring in order to keep the watch powered.

Sapphire crystal
First used for watches in the 1960’s, this hard, transparent material is made of crystallizing aluminum oxide at very high temperatures. Chemically, synthetic sapphire is the same as the natural sapphire used in jewelry, but without the coloring agents that give the gemstone its various hues.

Sapphire (whether natural or synthetic) is one of the hardest substances on earth. It measures 9 on the Mohs scale, which is a system for rating the relative hardness of various materials (diamonds measure at a 10, the highest rating possible). Watch crystals made of synthetic sapphire are often marketed as “scratch resistant”, meaning they are very difficult - but not impossible - to scratch. Indeed, a diamond can scratch it, and so can man-made materials that incorporate silicon carbide, often used to make simulated-stone surfaces for furniture or walls. The watch wearer should note that accidentally scraping a sapphire crystal against such a surface could cause a scratch.

Scale
The graduation of measurements on an instrument, showing divisions of a whole. In watch terms, these graduations are often used to measure minutes, seconds, and for special bezel functions like a tachymeter.

Shock-Resistant/Shock-Absorber
Watches provided with inner shock absorber systems help prevent damage from shocks to the balance pivots. With a retaining spring system, it assures an elasticity that absorbs the movements of the balance staff pivots when the watch case receives strong shakes or hits. After the shake, the spring system returns the balance pivots to their original position. Without this system in place, the constant shocks to the case could cause bending and eventually breaking of inner components.

Skeleton
This is a watch in which the case and various parts of the movement are not covered by a dial and therefore enabling the inner mechanisms of the watch to be seen.

Slip Clasp or Buckle
A clasp that slips back and forth over a strap or bracelet before being held in place with a latched snapping lock. Often these types of buckles provide a more comfortable fit for the wearer.

Small Second/Subsidiary Seconds
A display to which the seconds function is placed on a small sub-dial instead of in the center.

Snailing
A decorative spiral pattern often placed on the barrel wheel or other large wheels in an automatic movement.

Solar Tech
This is often associated with a watch that relies on solar energy to power the quartz movement within. This technology provides the accuracy of quartz, without the inconvenience and cost of regular battery changes.

Spring
The balance-spring (also known as a “hairspring”) of a mechanical watch requires one-millionth of a horsepower to maintain the motion of the balance. This power is delivered to it through the gear-train by the mainspring. Depending upon the particular watch-movement, the mainspring can continue to supply this power for two days or more. The mainspring is attached to the barrel and barrel-arbor by means of hooks and eyes and usually made of an alloy containing iron, nickel and chrome with traces of cobalt, molybdenum and beryllium. Springs of this type, of which the “Nivaflex” alloy is the most prominent example, embody a series of important advantages: they are nearly unbreakable, unaffected by magnetism, do not rust, and are resistant to deformation.

Stem
The thin piece of metal that connects the crown to the watch case.

Stopwatch
See Chronograph

Subsidiary Dial/Sub-Dial
A small additional dial or indicator placed off center from the main dial. Often these sub-dials are used for seconds, day, date, month, or 24-hour functions.

Sweep Seconds
A central seconds hand that ticks every half second and makes the hand appear as if its “sweeping” over the dial.

Swiss Made
Watches, clocks and alarm clocks manufactured in Switzerland bear the designation “Swiss made” (or its abbreviation “Swiss”) as well as the logo of the producer or distributor. This label (“place of origin” in legal terms) enjoys a solid reputation throughout the world. And globalization of trade has done nothing to diminish its importance. On the contrary, the modern consumer is looking for a maximum of information when he or she goes shopping for a new timepiece.

“Swiss made” embodies a concept of quality that has been forged over the years. It includes the technical quality of watches (accuracy, reliability, water-resistance and shock-resistance), as well as their aesthetic quality (elegance and originality of design). It covers both traditional manufacturing and new technologies (micro-electronics).

Moreover, a law “regulating the use of the name 'Swiss' for watches” sets out the minimum conditions that have to be fulfilled before a watch merits the “Swiss made” label.

This law is based on a concept according to which Swiss quality depends on the amount of work actually carried out on a watch in Switzerland, even if some foreign components are used in it. It therefore requires that the assembly work on the movement (the motor of the watch) and on the watch itself (fitting the movement with the dial, hands and the various parts of the case) should be carried out in Switzerland, along with the final testing of the movement. It also requires that at least 50% of the components of the movement should be manufactured in Switzerland

The Swiss watch industry is very active in safeguarding the integrity of “Swiss made” and its other regional labels of quality.

Excerpts taken from:

Federation of the Swiss Watch Industry FH. “The Swiss Watch Industry - Swiss Made.”.

Tachymeter/Tachometer (Ta-kah-mee-ter)
An instrument for measuring speed of a moving object, such as a car, over a given distance. The standard length of calibration for watches is kilometers per hour, though with America’s rising interest in the tachymeter design, some are calibrated to measure miles per hour as well. To effectively use a tachymeter, simply watch the seconds hand as it goes past a certain number on the scale around the dial. That number then represents the kilometers/miles per hour of the timed object’s speed. Often coupled with chronograph watches.

Titanium
Recently, the idea was presented for some sports watches to be made from a material that has the same strength as stainless steel, but without the excess weight. Already used in the construction of many crafts for space travel, Titanium had proven time and time again to be a reliable material. It is extremely durable and also hypoallergenic.

Tonneau
An elongated, barrel shape often used to explain a watch case’s appearance.

Tourbillon (Tur-bee-on)
Created in 1795 by watchmaker, Abraham-Louis Breguet, it’s meant to minimize positional errors. The balance-wheel and escape-wheel are mounted on a revolving platform geared to the third wheel so that it makes a complete turn every sixty seconds; thus any imbalance in the weight-distribution of these parts, which might otherwise affect the rate of the watch in some orientations, can make itself felt only for a few seconds each minute before being cancelled out by the change in alignment. Later chronometer-makers found that it was unnecessary to resort tothis very short of a cycle; the “karrusel”, a later development of the same idea, takes approximately 52.5 minutes to rotate.

Vibration
Movement of a pendulum or other oscillating element, limited by two consecutive extreme positions. The balance of a mechanical watch generally makes five or six vibrations per second (i.e. 18,000 or 21,600 per hour), but that of a high-frequency watch may make seven, eight or even ten vibrations per second (i.e. 25,200, 28,800 or 36, 000 per hour). Often shown as ‘V/h’.

Water Resistant
See our Water Resistance page for details

Wheel
A circular element, often with small teeth around it, that makes up part of a watch gear. Wheels in watch gears are often made of brass though some other materials have been known to be used such as Quinting watches which use wheels made of sapphire crystal to obtain their signature ‘transparent’ look.

Winding
Operation consisting in tightening the mainspring of a watch. This can be done by hand (by means of the crown) or automatically (by means of a rotor, which is caused to swing by the movements of the wearer's arm).

Window
A part of a watch dial that allows a view of a function or mechanism underneath. This term is often used for date indicators, but has also been used to explain exposed balance wheels and the like.

World Time
As one travels eastwards or westwards from zero degrees longitude (the Greenwich or “prime” meridian), one's local time deviates from GMT by one full hour for every 15º traversed. This world time system was first introduced by Canada and the USA in 1883. World time wristwatches were first made in the 1930’s. They are particularly popular with long-haul pilots, as well as with business people whom frequently make long-distance telephone calls and/or trips from one time zone to another.

Watches with World Time display all 24 time zones either on the dial itself or on the bezel, though are most often associated with digital watches.