Glossary of Watch Terms
Time to brush up on the lingo of watch aficionados.
12-Hour Recorder (or register): A chronograph subdial designed to measure time periods of up to 12 hours.
30-Minute Recorder (or register): Another chronograph subdial, which, as the name reveals, can record time for up to 30 minutes.
Alarm: An inbuilt watch device used to signal a pre-set time and indicate particular arrangements, duties and appointments for its wearer.
Altimeter: A dial-fixed device, predominantly used in mountaineering, which measures the altitude by reading changes in the pressure of the earth’s atmosphere. This technical method is known as barometry.
Analogue Watch/Display: The most common style of watch display, offering a reading of the time by means of three hands. The longest hand records the passing of each second, the second longest tracks minutes and the smallest indicates the hour. These hands whirl in a concentric circle over a round, dial designed to represent a whole, thereby a whole day (12-hour time span) or a whole hour (sixty minutes).
Analogue Digital: This is a design that incorporates the best of both worlds – a watch with both a digital display and the triple handed display of an analogue watch.
Aperture: An aperture is an aesthetical quirk, essentially a small opening, featured on some watch dials. Apertures are commonly used to off extra indications, besides the time, such as the day of the year or the month, etc….
Assembling: The process of assembling involves the arrangement of dynamic mechanical components. In the past this painstaking task would’ve been performed by the hands of a skilled craftsman. Today, however, this process is usually automated, but that’s not to say that humans are now redundant. Indeed a human touch is still needed to complete the assembling process, namely when inspection or testing is required.
Automatic Movement/ Winding: Watches powered by Swiss-invented automatic movement don’t require winding. Instead the watch uses a rotor, an essential component of the automatic mechanism, which winds the mainspring whenever your hand is in motion. This causes the winding stem to turn and provide energy to the watch’s mainspring. Once fully wound the automatic reserve power can last for up to 36 hours. Automatic movement watches are becoming increasingly more popular amongst watch connoisseurs, offering a Swiss response to the motion-powered quartz movement of Japanese watches.
Auto Repeat Countdown Timer: This countdown timer automatically resets and restarts when the pre-set time elapses. The timer then runs on a cycle and will keep restarting until the wearer hits the stop button.
Balance Spring: A fine spring, sometimes referred to as a ‘hair spring’, featured in a mechanical watch, which keeps the balance wheel in a neutral position.
Balance Wheel: This is the oscillating part of a mechanical watch, much like the pendulum in a grandfather clock, which rotates back and forth around a spiral torsion spring. Each swing of the wheel, known as a ‘beat’, spins the intricate gear train and moves the dial hands forward.
Barrel: The barrel is, as the name suggests, a thin cylinder, within which the mainspring of the watch is fitted. The toothed edge of this barrel comes into play as it turns and drives the gear train.
Bezel: The bezel is the ring that encircles and frames the watch face. Usually the bezel is made of gold or at least gold-plated, however steel is also popular for bezels, especially if the dial is black, as the silver frame offers a gleaming contrast used to accentuate the face.
Bi-directional Rotating Bezel: This bold bezel wheels either clockwise or counter-clockwise and can be used to make sea diving calculations or to easily record elapsed time.
Bracelet: A style of linked watch band often made of silver stainless steel.
Bridge Movement: In a bridge movement watch the back plate is replaced by sinuous metal bars called bridges. The bridges are mounted within the frame and used to uncover the inner mechanisms. They can also be removed without disrupting the gear train.
Cabochon: This gleaming blue gemstone is used as decoration for luxury timepieces and sometimes neatly rounded and polished to adorn the crown.
Calendar: A feature used to indicate the day of the month, week and year. This subtle feature is included on a range of watches in a variety of styles.
Caliber: The term ‘Caliber’ is popular amongst Swiss watchmakers who use it to distinguish a specific watch model, such as Tag Heuer’s Aquaracer Caliber 5. In other cases the term has also been used to differentiate various movements.
Cambered: A cambered dial or bezel is distinguishable by the slight curve or arch that distorts its rounded shape.
Case: The case is one of the better known terms in horology. It refers to the metal housing that encases the watch’s movement, keeping the intricate mechanisms protected. Most cases are made using stainless steel and, in other cases, titanium, silver, gold or platinum is used, as well as silver-plated brass for cheaper watches.
Caseback: The reverse side of the watch casing – the side often hidden by your wrist – is known as the caseback. With some of the more innovative designs the caseback is either transparent or bridged to uncover the intricate inner workings of the watch. A lot of high-end manufacturers will also etch their brand onto the caseback, along with any other details about the watch’s individual features.
Chime: A ringing chime is sometimes made to sound within a watch to signal the striking of the hour. Perhaps the most famous example of this sound is the rolling toll that echoes through London whenever Big Ben marks the hour.
Chronograph: A term that often recurs in horology, a chronograph is a type of stopwatch with an in-built timer that can be started and stopped. There are a number of different styles of chronograph, some of which use a centred seconds hand on the main dial. Others crowd the watch face with smaller subdials used to register elapsed seconds, minutes and hours. Then there are those pieces that measure elapsed time using a digital display, commonly featured on the dial. Interestingly there are several other examples of specialised scales being used on watch dials to serve different functions. Sometimes these chronograph scales can even measure the distance the wearer has travelled.
Chronometer: This term chronometer is the designation used for a precision watch that has been specifically tested in a variety of temperatures and conditions. Chronometer timepieces are required to meet the strict standards of COSC, an official quality-assuring institution in Switzerland. Once a chronometer has been approved it will then receive a certificate, along with the coveted COSC hallmark.
Complication: Don’t let the name put you off, a complication watch is simply one that possess other functions, besides timekeeping. Take a chronograph, for example – if you wanted to be very technical then you could refer to it as a watch complication. There are other complications, of course, including minute repeaters, tourbillons and perpetual calendars.
COSC: Contrôle Officiel Suisse des Chronomètres is the chronometer testing institute responsible for putting every certified chronometer watch, like a pedantic drill sergeant, through 15 days of rigorous quality assurance tests in order to verify the watch’s quality.
Countdown Timer: The countdown function allows a wearer to record the pre-set elapse of an adjustable period of time. In some cases a countdown timer will sound a final warning signal prior to the last few seconds. This function is particularly useful for anyone who takes part in sporting events like track races.
Crown: The crown is the button on the side of the watch casing (some are more protrusive than others) used to adjust the time, calendar and also to wind the mainspring in mechanical watches.
Crystal: A transparent cover that protects the watch dial and subdials, often made of synthetic sapphire, glass crystal, or, in cheaper watches, plastic.
Day/Date Watch: As the name implies, the day/date watch features a dial mounted display that indicates the day of the week, as well as the date itself.
Day/Night Indicator: Another aesthetic quirk, this coloured or shaded band is featured on world time watches to distinguish time zones by simulating the cycle of daylight and darkness.
Deployment Buckle: A buckle bracelet fastened using an adjustable hinged extender. It’s a little more expensive than the classic belt-buckle, but it’s easier to fasten and rests more comfortably on the wearer’s wrist.
Depth Alarm: The depth alarm is fitted onto a diver’s watch and used to signal them when they go below a pre-determined depth. In some watches the same alarm can also be used to alert the diver when they ascend above that set depth, warding them away from the dangers of decompression sickness.
Dial: The dial is the main centrepiece on a watch face, onto which a ring of numerals and indices are skilfully applied, as well as a variety of coloured surface designs.
Digital Watch: A watch that displays the time using digits instead of a dial and hands that whirl in concentric circles.
Direct-drive: A function that advances the second-hand in intervals instead of a flowing motion. The direct-drive mechanism allows for more accurate timekeeping by placing emphasis on each individual second.
Dual Timer: A watch made to measure both local time and at least one other time zone in the form of a twin dial, smaller subdials or an additional hand.
Elapsed Time Rotating Bezel: A rotating bezel allows the wearer to measure elapsed periods of time. The adjustable bezel can be turned to match the zero on the bezel with the watch’s second or minute hand. By doing this the wearer can read the elapsed time from the bezel.
Engine Turning: A fine geometric pattern engraved onto metal as a form of decoration on the reflective watch face.
Escapement: This little device is fitted into a mechanical movement and used to translate rotational energy into a lateral movement. The perpetual tick-tock noise you hear when you press your ear against your watch is caused by the escapement mechanism. Like a column of dominos the balance wheel vibrates and shifts the pallet fork (between the escape and balance wheel) causing it to lock and unlock rhythmically.
Face: The front of the watch, also known as the dial, which is marked with either Arabic or Roman numerals, protected by a transparent cover and framed by a decorative casing.
Flyback Chronograph: This complication watch features a reset function, commonly used to time laps and record finishing times, without needing to stop the chronograph.
Gasket: A water resistant watch will often come equipped with gaskets used to seal the case backing and protect the crystal and crown from contact with water during every day wear. Gaskets should be examined every year in order to keep their water resistance.
Gear Train: This intricate gear system is often seen in pieces on a workshop bench and used in promotional videos to unravel the mystique of watch making. Essentially the gear train is the complex mechanism which transfers power from the mainspring through the escapement.
Gold Plating: In order to apply the gold effect to cheaper timepieces a layer of gold will sometimes be electro-deposited onto metal, the thickness of which is measured in microns.
Grande Sonnerie: The Grande Sonnerie is complication in a style of repeater watch that signals hours and quarter hours at the request of the wearer.
Guilloche: The guilloche technique creates an intricate and decorative pattern painstakingly etched onto an underlying metal, chipped in a circular motion, using an old-fashioned machine called a rose engine lathe.
Hard Metal: Hard metal is a scratch resistant alloy comprised of several combined materials, like titanium and tungsten carbide. These elements are then pressed into hard metal and polished using glittering diamond powder to enhance its brilliance.
High-Tech Ceramic: A form of watch protection also used to bolster space crafts and stop them from breaking up when they hurtle through Earth’s atmosphere. High-tech watch ceramic is often polished using diamond dust and enhanced with a polished finish. It can also be injection moulded and neatly contoured to provide innovative, smooth-surfaced designs of various colours, although black is the most commonplace.
Horology: The preferred designation used to encapsulate the sweet science of measuring time, which includes the art of crafting fine timepieces.
Index: Indices are used on analogue watch dials as hour indicators and sometimes favoured instead of numerals.
Integrated Bracelet: An integrated bracelet refers to a bold design with a bracelet attached to the casing that frames the dial.
Jewels: Watch designs often feature synthetic sapphires or rubies essentially used as bearings to separate the gears of a mechanical watch and reduce friction.
Jump Hour Indicator: Jump hour indicators are used in the place of an hour hand and most often found in the form of a wheeled numeral viewed through an aperture.
Lap Timer/Memory: The in-built lap memory function is found in a variety of quartz sports watches and is used to record the times of multiple laps in the same race. These times are kept by the lap timer, which is another chronograph function used to memorise different segments of a race. The wearer simply has to push a button in order to freeze these times on the digital display.
Limited Edition: A term often attached to a particular style of watch manufactured in a finite amount and available for a limited period of time. Most watch manufacturers will offer a refined selection of limited timepieces, which are often highly prized by collectors.
Liquid-Crystal Display: An ingenious digital display that electronically shows the time using an amount of backlit liquid pinned between two transparent plates.
Lugs: The protrusive ends of the watch face, between which the watch bracelet is fixed. They’re easy to spot simply because they look like the pricked lugs of some kind of wolfish animal.
Main Plate: A base plate which acts as a foundation upon which the intricate cogs and wheels of a watch movement are mounted.
Mainspring: A spiral torsion spring, held in the barrel, within the gear train of a watch interior. The mainspring is essentially a power source for mechanical watches.
Manual Wind: Manual wind watches need to be wound daily using the crown. Despite that minor inconvenience they’ve still been wrought in large numbers by seasoned Swiss watchmakers. In fact some of the most stunning and coveted timepieces made today are wound manually. Exhibition case backs are common too, since the intricate active movement is a very pleasing sight without the rotor to obscure it.
Marine Chronometer: An advanced, and slightly oversized, timepiece that is so accurate it can be used as a portable time standard. The large watch face is framed by a protective box, which is why they’re referred to as box chronometers. They’re often found on-board ships, close to the helm, where they provide longitude readings to the crew. Marine chronometers can be either electronic or mechanical, but the latter requires a gimbal mount in order to remain in a horizontal position and retain precision.
Measurement Conversion: This feature is a graduated scale etched onto a watch’s bezel, allowing the wear to convert measurements, such as turning miles into kilometres.
Mechanical Movement: A common term used in reference to a particular movement that operates around a hand-wound mainspring. Once the mainspring has been tightened it will slowly unwind in an even motion, powering the watch. Automatic mechanical watches don’t need to be wound because the mainspring winds itself whenever the wearer moves their wrist.
Micron: The micron is a miniscule unit of measurement used to calculate the thickness of gold-coating. 1000 microns is equal to 1 millimetre.
Military or 24-hour Time: Time is divided into 24-hour segments equivalent to, as you already know, a day. In order to convert 12-hour time into a 24-hour day you simply have to count upwards, adding 12 (hours) to a.m. time. By doing this midnight, which is 12:00 in 12-hour time, becomes 00:00, resetting the 24 hour cycle. You might be familiar with the pronunciation of military time – known to the everyman because of countless war movies – like “zero-six-hundred”, which would be 06.00 a.m..
Moon-phase: A decorative window featured on a watch face to record what phase the moon is in, be it waning crescent or waxing quarter etc….
Mother-of-Pearl: The iridescent inner shell of a freshwater mollusc is sliced thin and incorporated into watch dials. Distinguishable by its milky lustre, mother-of-pearl is found in an array of silvery colours from grey to salmon.
Movement: The movement is the interior mechanism, either mechanical or quartz, which records time by turning the watch’s hand, calendar, moon-phase, etc….
Mystery Watch: Vincent Calabrese is an Italian-born watchmaker whose patented invention, the mechanical Mystery Watch, indicates hours, minutes or seconds without using hands. The hour window circles clockwise around the minute scale while the second indicator, an arrow, wheels slowly around the revolving dial. Interestingly the wearer can also breathe on the crystal face to reveal the word ‘mystery’.
Pedometer: This in-built device is popular for sports watches as it counts the number of steps the wearer makes, responding when the wearer’s foot hits the floor.
Perpetual Calendar: The perpetual calendar automatically adjusts itself to compensate for the varying lengths of months and also for leap years. They are driven by either a quartz or mechanical movement and are supposedly designed to be accurate until year 2100. Experienced watch collectors often advise owners of mechanical perpetual calendars to keep them inside motorised winding boxes to preserve the calendar countdown.
Platinum: A very rare, tarnish-resistant and strong precious metal that’s popular for gemstone settings and watches alike. Recognised for its piercing white lustre, Platinum is commonly used to subtly direct the eye and to generally create an understated look . Many platinum timepieces are also limited edition, owing to the cost and rarity of the metal.
Power Reserve/Indicator: An amount of stored-up energy reserve that continues to power a watch before it stops. This is often displayed using a small sub-gauge positioned somewhere on the dial.
Pulsimeter: Another popular function for sports enthusiasts, the pulsimeter is a scale on chronograph watches that measures the wearer’s heartbeat via their pulse.
Push-piece: A button that has to be pressed in order to work a particular mechanism, like the alarms and timers on chronographs.
Quartz Crystal: A tiny piece of synthetic quartz that acts as a veritable linchpin in the watch movement and oscillates at a rate of 32.768 times a second. This rapid motion interacts with the watch’s circuitry and thereby divides time into various equal segments.
Quartz Movement: An innovative movement, popular in Hong Kong, Japan and Switzerland, which enables a watch to run without needing to be wound. The accuracy of this movement depends on the vibrations of a quartz crystal that draws energy from a battery the wearer must replace roughly every 1.5 years. However the latest quartz technology has been adapted to allow the watch to recharge on its own. Power is generated using movement, similar to an automatic mechanical, or, alternatively, by using light from a solar cell or body heat.
Repeater: A button-triggered device that indicates the time using a series of repeated chimes.
Rose (or pink) Gold: This retro style of faintly hued gold is a customer’s favourite – particularly in Europe – that contains the same elements as yellow gold. The only difference is that the rose gold alloy possesses a higher concentration of copper.
Rotating Bezel: A rotatable bezel that the wearer can turn for different methods of timekeeping and other mathematical functions.
Rotor: The interior part of an automatic watch that spins the movement’s spiralling main spring.
Sapphire Crystal: The transparent crystal used to cover and protect the fragile watch face, usually made of synthetic sapphire, which is both shatter and scratch resistant.
Screw-Lock Crown: A special crown for the wearer to screw into the case, ensuring that the watch is watertight.
Second Time-Zone Indicator: An additional subdial that displays the time for another time zone. With this function the wearer is able to read local time while simultaneously having access to the time in several other countries.
Shock Absorber: A resilient bearing, commonly found in adventure models, which absorbs shocks taken by the watch’s interior balance staff (an integral part of the gear train) and prevents any damage being caused to the fragile pivots.
Shock Resistance: As dictated by the US regulation bods, a watch’s shock resistance is determined by testing its ability to withstand an impact equal to falling 3 feet onto a hard wooden floor.
Skeleton Case: The skeleton case has both a transparent front and back, uncovering the watch’s intricate inner workings.
Slide Rule: Another dial-mounted addition consisting of a logarithmic scale – used to perform mathematical calculations – on the outer rim of the watch face.
Solar Compass: A compass that can indicate the geographical poles using a rotatable bezel. The wearer simply turns the hour hand to point to the sun and then measures half the distance between the position and 12 o’clock. Finally the wearer turns the bezel so that the ‘south’ marker meets the halfway point. Alternatively there are several types of quartz watches with inbuilt solar compasses that show these directions by means of an LCD display.
Solar Powered Batteries: The batteries of a quartz watch that can be recharged with the encircling solar panels on the watch face.
Split Seconds Hand: A clever device used for timing different events that start but don’t end at the same time. This utilises two hands, one of which is a flyback hand, while the other is a standard chronograph hand. By starting the chronograph the wearer sets both hands into motion. The wearer can then time laps or separate finishing times by freezing the flyback hand while the chronograph hand continues spinning, effectively ‘splitting’ the hands – hence the name.
Stainless Steel: Popular for watch casings, this durable metal alloy, composed mostly of chromium, is practically unsusceptible to rust, corrosion or discoloration. In order to achieve the sheen of a more precious metal the steel can also be polished. For this reason, as well as the general popularity of white metal jewelry, steel has often been celebrated as the perfect setting for diamonds. But let’s get back to watches shall we? In the design of fine timepieces stainless steel is favoured for casebacks due to its exceptional durability.
Stepping Motor: The stepping motor is an integral piece of a quartz movement used to rotate the gear train, which then sets the watch’s hands into motion.
Sterling Silver: Another option for watch casings, this white and reflective precious metal is an alternative to its slightly less alluring cousin: stainless steel. Sterling silver is 92.5% pure silver, which, although it’s less durable than stainless steel, is often found in elegant watches that are design to carry the same sophistication as sterling silver jewelry. An additional coating is sometimes added to counter the dull effects of tarnishing.
Stopwatch: A stopwatch is equipped with a seconds hand that measures the passage of time. When this function is built into a standard watch, both the added device and the timepiece itself are designated the title ‘chronograph’.
Subdial: This little watch face mounted dial serves several purposes, such as tracking elapsed minutes on a separate timescale or recording the date.
Swiss Made: If a watch carries the verified trademark of a Swiss made item then it will be awarded a greater credibility amongst watch aficionados. This mark is only earned if the movement was assembled and approved by an established manufacturer in snowy Switzerland.
Sweep Seconds-Hand: The sweep seconds-hand is clearly visible as it’s always mounted at the centre of a watch dial.
Tachymeter: An additional function on a chronograph watch that records the speed at which a wearer crosses a pre-determined distance, commonly used for timing sprint runs.
Tank Watch: It was Louis Cartier who first conceived this unique style of rectangular watch. Supposedly the bold bars that shape the sides of the casing were based upon the tracks of WW1 tanks.
Telemeter: The telemeter, also sometimes referred to as a rangefinder, is a device that calibrates the distance an observer has to travel before they reach an object by measuring how long sound takes to cross said distance. An obvious example of this function being put to use is the moment when lightning strikes, which is when the wearer would activate their telemeter, to the moment the thunder is actually heard. The telemeter looks a lot like a tachymeter and is basically a chronograph with a special scale that encircles the outermost edge of the watch face.
Timer: An instrument used to measure intervals of time and various durations without offering an indication of the time of day.
Titanium: Titanium is a ‘space age’ metal often found with a silvery-grey appearance. Its prolific usage in watchmaking, namely sports watch designs, is the direct consequence of it being 30% stronger and almost 50% lighter than steel. Basically it’s an adventurer’s metal, also known for its resistance to corrosive salt water, qualifying it as a favourite amongst divers. The fact it can be easily scratched means that manufacturers will often protect it with a patented-coating to stop scratching.
Tonneau Watch: A distinctive watch designed with two convex sides and shaped like a barrel.
Totalizer: An in-built mechanism that tracks elapsed time and displays it using a subdial.
Tourbillon: An intuitive device in a mechanical watch that makes timekeeping errors redundant by counteracting the difference between the running rates of watches held in horizontal and then vertical positions. The tourbillon achieves this by using a round carriage, or cage, that holds the escapement and the balance and is also built to rotate at the steady rate of once per minute.
Tritium: An isotope of hydrogen responsible for the activation of luminous spots or indices that illuminate the watch dial. It should also be noted that the radioactivity released during this process is far too minor to pose a health risk.
Two Tone: Two tone watches feature two combined metals, namely yellow gold and stainless steel when it comes to fine, high-end watches.
Uni-directional Rotating Bezel: A style of rotatable bezel that measures elapsed periods of time, but can only be adjusted in a counter clockwise rotation. Popular for precise activities, this function is designed to stop divers from inadvertently knocking the bezel and making an erroneous estimation of their remaining air supply. As mentioned the bezel only moves one way meaning the diver can slip up and still be safe whilst timing their dive. When incorporated into divers’ watches this bezel is also ratcheted, which allows it to lock into place for added safety.
Vibration: No doubt a word you’re familiar with, vibration in watches refers to the movement of a pendulum or other oscillating component. The central balance wheel within a mechanical watch vibrates about six times per second, whereas a more effective high-frequency watch could accelerate up to between seven or ten vibrations per second.
Waterproof: Beware of this term because, when it comes to watches, it is a misplaced appendage that serves no other purpose than to confuse the customer. Remember, no watch is 100% waterproof.
Water Resistance: Water resistant watches are built to deflect moisture and rain. However these particular timepieces shouldn’t be worn whilst swimming or diving. However these watches can be submerged underwater and are emblazoned with details that state at what depth the piece remains water resistant. For example, most standard sport watches can be taken down to 50 metres. At the same time there are precious few watches that can follow you on a 200 metre scuba diving descent.
White Gold: An alternative to yellow gold, this eye-catching metal contains an added amount of either nickel or palladium to the alloy, which is the reason for its stunning white color. For the most part high-end white gold watches will be around 18k.
Winding: An operation that involves the tightening of a watch’s mainspring. This is usually performed by hand, using the crown, or also automatically with a rotor that swings using the motion of the wearer’s arm.
Winding Stem: The button, also known as the ‘crown’, which is positioned on the right side of the watch case and used to wind the mainspring.
World Time Dial: This particular dial features an outer edge that provides the time in up to 24 other time zones across the globe. These zones are usually represented with city names etched onto the bezel or dial. The wearer can find an accurate reading for each respective time zone by looking at the city next to the one indicated by the hour hand. Watches with this luxury feature are commonly called ‘world timers.’
Yacht Timer: A specific countdown timer that offers alarm signals matched to the countdown that precedes a boat race.
Yellow Gold: The most popular and widely known style of gold. For the most part yellow gold watches are a stunning 14k or, as with a number of refined European manufacturers, 18k.