Tourbillon, Uni-directional rotating bezel, applique, tang buckle! What the hell am I talking about?
Have you heard a term related to watches that you just don’t understand? Maybe you have heard somebody talking about their latest timepiece and you just nod and smile and pretend that you know what they are talking about. Well, chances are, they don’t know what they are talking about either and they are just repeating, parrot-fashion, what the oh so knowledgeable salesman told them in order to persuade them to part with their hard-earned money!
Now is your chance to get one over on your friends and familiarise yourself with the terms used in all things horology (look that up!). Yes, it is a long list, but there are a lot of terms, some of which you may be familiar with, but many you will not!
If I have missed any, please do let me know!
The Terms (no conditions)
Adjusted: An adjusted watch is calibrated to keep accurate time under various conditions. The 9 basic adjustments are: Stem up, Stem Down, Stem Left, Stem Right, Face up, Face Down, Heat, Cold, and Isochronism.
Alarm: A function on a watch that will make a sound or vibration at a preset time. Mechanical alarms have an extra hand to set the time of an alarm. There is usually a second mainspring that powers a small mechanism that makes a tiny weight vibrate back and forth causing both a noise and the watch to vibrate at a designated time.
Altimeter: A device that determines altitude, or height above sea level, based on changes in barometric pressure. Recording ascent and descent, an altimeter watch is an important piece of equipment for climbers, walkers, mountaineers and aviators. Often found on sports watches.
AM/PM Indicator: see Day/Night Indicator
Amplitude: Maximum angle by which a balance swings from its position of rest.
Analog: A watch that has hour and minute hands to tell the time, rather than a digital display.
Analog-Digital Display: A watch that displays the time using both hour and minute hands (analogue) and via a digital display. Also known as duo display or an AnaDigi watch.
Annual Calendar: A complication showing the date. Mostly just day and month at the minimum, although some will also display Moonphase. Will automatically adjust for short and long months, but does not account for leap years.
Anti-Magnetic: A watch that has been manufactured to resist becoming magnetized. Mechanical watches, that are not anti-magnetic, can be thrown off balance if they come into contact with a strong magnetic field.
Aperture: A small opening in the dial, such as the ones used to display the day and date. In “jump hour” watches the Aperture will be used for displaying the time.
Applique: Applique or applied chapters are numerals or symbols cut out of sheet metal and attached to the dial.
Arabic Numerals: 1, 2, 3, 4, 5, 6, 7, 8, 9, 0
Arbor: This is any post or axle that a moving part swings or rotates upon, such as a gear with an axle running through the centre.
Assembling: The process of putting together a watch. The assembly and manufacture of parts was formerly done entirely by hand but today are done by machine with inspection and timing for accuracy done by hand.
Auto Repeat Countdown Timer: A countdown timer that resets itself as soon as the preset time has elapsed and starts again. The countdown is repeated continuously until the stop button is pushed.
Automatic Watch / Automatic Winding: A watch that is wound by the everyday movements of the wearer. A tiny rotor turns and swings whenever the watch is moved. This in turn rotates a tiny gear, which ratchets the larger mainspring gear one click at a time. The system was invented in Switzerland by Abraham-Louis Breguet in the 18th century and was first used in a wrist-watch by John Harwood. It is important to understand that automatic watches also require a manual wind every so often. An automatic watch that has stopped or is at the end of its power reserve due to non-wear should be manually wound 30-40 times. Manually winding an automatic watch after the power reserve has ebbed or the watch has stopped ensures the watch is at full reserve when first worn, so as long as the watch is worn it will remain fully wound. When removed, the watch will continue working for the specified amount of time as indicated in your manual (generally 35-45 hours).
Auxiliary Dial: A smaller extra dial within the main dial, such as a seconds dial.
Balance: Moving part, usually circular, oscillating about its axis of rotation. 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 Cock: A small bridge that secures the balance wheel with the movement.
Balance Spring (Hairspring): A very fine spring in a mechanical watch that causes the recoil of the balance wheel. The length and adjustment of its length regulates the timekeeping.
Balance Staff: Shaft or “arbor” upon which the balance swings back and forth. This is the “heart” of a watch.
Balance Wheel: The part of a mechanical watch movement that oscillates, dividing time into equal segments. This is the regulating mechanism that controls the watch’s timekeeping accuracy.
Barrel: A drum that holds the Mainspring in a mechanical watch. The size of the barrel directly affects the length of the Power Reserve. Some watches feature a Double-Barrel which allows for extra long power reserve. The toothed rim of the barrel drives the train.
Battery EOL: Battery End of Life indicator. This function forewarns of impending battery failure in a quartz watch by means of the second hand jumping in two or sometimes four-second intervals. Occurs approximately two weeks before battery failure.
Battery Reserve Indicator: see Battery EOL
Bezel: A Bezel is a ring on the top side of the case around the crystal. The Bezel’s purpose is to measure time increments. Some bezels are fixed, some can be turned in only one direction (unidirectional), whilst others can be turned either way (bi-directional). Rotating Bezel are used to time an event by aligning the bezel’s.
Bi-Directional Rotating Bezel: A bezel that can be rotated either clockwise or counter-clockwise, to be used for mathematical calculations, such as average speed, average distance, or elapsed time.
Blacksteel: A DLC (diamond-like carbon) Coating used on a few of Breitling’s limited edition models. It is an extremely hard surface coating that gives the watch a black appearance.
Box Hinge Case: A case with heavy reinforced hinges and heavy metalwork supporting the bow/pendant
Bracelet: The metal strap that goes around the wearer’s wrist. A watch bracelet is typically made up of flexible, separate links that can be added or removed to adjust the bracelet’s length.
Breguet Spring: The spiral hairspring on which the balance swings tends to bunch on opposite sides as it expands or contracts. The constant shift in their gravity disturbs the rate of balance, and Breguet solved the problem in 1795 by upraising the last coil of the spring and giving it a smaller curve. This Breguet overcoil encouraged the spring to develop concentrically, improving the rate of the watch and reducing the wear on the balance pivots.
Bridge: A part that is fixed to the main plate to form the frame of a watch movement. All other parts are mounted inside the frame.
Built-in Illumination: A light on a watch that enables it to be read it in the dark.
Cabochon: A decorative stone that has been carved into a round shape.
Calendar: A feature that shows the date, and often the day of the week. There are several types of calendar watches. Most calendar watches show the information digitally through an aperture on the watch face. Some chronograph watches show the information on sub-dials on the watch face.
Caliber: A number and letter designation that identifies a watch movement, shape, layout or size.
Cambered: Often used in referring to a curved or arched dial or bezel.
Case: The metal housing that contains a watch’s parts. Stainless steel is most commonly used. While titanium, platinum, gold and silver are also common, they will increase the price of the watch.
Caseback: The back side of a watch case (the side that lies against the skin).
Case Materials: The materials used in a watch case. Can be inexpensive cast metal or a solid metal, such as steel, gold, platinum, or titanium. Some watch cases have gold plating over brass.
Chapter Ring: An outer ring around a watch dial that contains some sort of unit measurement of time such as minute increments. A chapter ring can be attached to the dial separately or painted directly on the dial.
Chronograph: A watch with a stopwatch function. A Chronograph both measures and displays elapsed times in addition to showing conventional time. Generally, the chronograph mechanism is driven by the movement of the watch and operated by two buttons on the edge of the case which start, stop and reset the chronograph. Usually the chronograph seconds hand is the large centre seconds with sub-dials for elapsed minutes and hours – although the exact display may vary.
Chronometer: Technically speaking, all watches are chronometers. A precision watch with a movement that has been rated by the official Swiss testing laboratory called the Controle Officiel Suisse des Chronometeres (aka COSC). The standard procedure involves measuring the performance of the movement at 3 different temperatures and in 5 different positions for 15 consecutive days. Mechanical movements that are accurate to -4/+6 seconds per day are awarded a chronometer certificate. Quartz movements must be accurate to +/-0.2 seconds per day, due to the fact that Quartz movements are inherently accurate and do not vary based on position and temperature. Very few brands go through the expense of certifying their Quartz movements. Breitling, however, is one company that does certify their quartz movements – the result is a highly accurate instrument.
Complications: A watch with functions other than timekeeping. A simple complication would include various chronographs, alarm, annual calendar and GMT functions, to mention a few. A watch with high complications would be called a Grand Complication and would include a perpetual calendar, Tourbillon, minute repeater or equation of time functions, and others. A watch with any additional function is called a complicated watch.
C.O.S.C.: Control Officile Suisse de Chronometers or Swiss Controle Officiel des Cronometres- the independent Swiss regulatory organization that rigorously tests and certifies (or fails) watch movements for chronometer status.
Cosmograph: Similar to a chronograph but with the tachymeter on the bezel instead of on the outer rim of the dial.
Côtes de Genève: A form of decoration in higher grade watch movements which look like stripes on the movement plates. Also called Geneva Stripes.
Countdown Timer: This allows the wearer to know how much of a preset time has passed. Some Quartz versions sound a warning a few seconds before the pre-set time has elapsed
Crown / Stem / Pin): The button on the outside of the watch case used to set the time and date. In a mechanical watch the crown also winds the mainspring. If the crown screws into the case (called a screw-in or screw-down crown), it makes the watch watertight.
Crystal: This is the clear cover on the watch face (dial). It may be made of glass, plastic, mineral crystal or sapphire crystal (a scratch-resistant synthetic material). Its purpose is to protect the watch face.
Cuvette: Inner dust cover on a watch case.
Day/Date Watch: A watch that shows both the day of the week and the date of the month.
Day/Night Indicator: A feature that indicates whether the indicated time is AM or PM. This feature can be found mostly in watches with a GMT/Dual time display or a World Time Display to help know whether it is day or night in the other time zones.
Dead-Beat Seconds: A complication on a mechanical watch where the second hand does not sweep, but jumps forward in one second intervals, much like a quartz watch.
Deployment/Deployant Buckle: A buckle that attaches to either side of the strap. The buckle is expandable so that the watch can be slipped on the wrist and snaps shut on the wrist. Once set to the correct size it need not be resized, thus reducing stress to the strap and elongating its life. This buckle also offers additional security while putting on and taking off the watch.
Depth Alarm: An alarm on a diver’s watch that sounds when the wearer exceeds a pre-set depth.
Depth Sensor/Depth Meter: A device on a diver’s watch that determines the wearer’s depth based on water pressure.
Dial: The watch face (plate of metal or other material). Dials vary in shape, decoration, material, etc. The indications are given by means of numerals, divisions or symbols of various types.
Digital Watch: A watch that shows the time in numbers, or digits, rather than hands and a dial (analogue). Liquid crystal display (LCD)is commonly used.
Dimaskeening: Fancy decorative etching on some watch movements.
Direct-Drive: A function that allows the second-hand to advance in intervals instead of a smooth sweep, allowing for more precise timekeeping.
Dive Watch: Dive watches are watches which have a minimum 200 meters of water resistance. In addition, they often have an elapsed time bezel, highly visible hands and markers and are constructed of materials that resist corrosive salt water.
Dual Timer: A watch that shows local time and the time in at least one other time zone. This is generally displayed by an additional hour hand which tracks time in a 24-hour mode. Some watches have a separate sub-dial showing the full clock at the additional Time Zone.
Duo display: A display that shows the time both by hour and minute hands (analog) and by numbers (digital). This is also known as AnaDigi display.
Ebauche: A watch movement manufactured with the purpose of being assembled into a completed watch elsewhere. Many “no name” watches are called Ebauche. Many times the movements, dials, hands, and cases were all manufactured by separate makers and later assembled.
Eco-Drive Technology: Solar power technology employed by Citizen Watches in most of its quartz models.
E Ink: Technology used in the display of Phosphor Watches which replicates the appearance of paper and ink. Also called Electronic Paper Display, or EDP, the technology is based on small capsules, about the diameter of a human hair filled with an equal number of negatively charged black particles and positively charged white particles floating in a clear liquid medium. The capsules are arranged in a thin sheet and laid over electronic circuitry which can form patterns of pixels. The patterns of pixel cause the black and white particles in each capsule to gravitate either to the top or the bottom of the capsule. What the viewer sees on the watch’s dial is an actual fluid ink display that can change instantly.
Elapsed-Time Rotating Bezel: A graduated rotating bezel that is used to keep track of periods of time. The bezel can be rotated so the wearer can align the zero of the bezel with the watch’s minutes or seconds hand. The elapsed time can then be read off the bezel, rather than the wearer having to perform a subtraction necessary if he used the watch’s regular dial.
Electronic (Quartz) Watch: A watch that uses an electric current. While most are battery powered, some use solar cells to transform light into electrical energy.
Elinvar: A hairspring made from a specific mix of metals that is resistant to changes in temperature, therefore, more accurate in different situations (including hot and cold). Derived from the term Elasticity Invariable.
End Shake: When a jewel hole is worn, allowing an arbor to shake.
Engine Turning/Turned: This is a centuries-old craft that, still today, involves the use of antique machines to engrave delicate patterns on metal watch components, including cases, dials, bezels and movements. It is also known as guilloche.
EOL: see Battery EOL
Equation of Time (EOT): A complication which indicates the difference between “true” solar time (that of nature) and “mean” solar time (that of man). As the earth orbits around the sun in an elliptical (oval) shape and the axis is tilted – there are only 4 days a year when the day is exactly 24 hours long – April 15th, June 14th, September 1st and December 24th. All other days of the year, the days are shorter or longer – depending on the position of the earth. This watch will show the difference between the “mean” time and the “true” time. Since the number of the days are fixed year after year (at the same location) a watch can be manufactured to replicate the correction via a shaped cam which elongates and shortens the days accordingly.
Escapement: The device at the heart of virtually all time-keeping mechanisms. It provides the impulses to maintain the oscillations of the balance wheel or pendulum which governs the rate at which the escapement lets the wheels and hands of the watch revolve.
Face: The visible side of the watch, also called the dial.
Flyback Hand: A second hand on a chronograph that can be used to time laps or to determine finishing times for several competitors in a race. Start the chronograph, putting both the flyback hand and the regular chronograph seconds hand in motion. To record a lap time or finishing time, stop the flyback hand. After recording the time, push a button and the hand will “fly back” to catch up with the constantly moving elapsed-time hand. Repeat the process to record as many lap times or finishing times as needed. In chronographs with numerical display, a “function” having the same effect.
Fob: Watch chain
Fork: Part of the Pallet-Fork and Arbor. The fork engages the roller jewel on the balance, and resembles a small pitch-fork.
Full ling: A Breitling watch that has a minimum lug width of 24mm and a diameter of at least 46mm and is accompanied by a metal bracelet, not a strap. This diameter applies to round Breitlings.
Function: A term used to describe the various different tasks a watch can perform such as chronograph and countdown timer. These are also known as complications.
Gasket: Seals the case back, crystal, and crown to protect against water infiltration during normal wear. The gaskets should be checked every two years to maintain the watch’s water resistance.
Gear Train: The system of gears which transmits power from the mainspring of the watch to the escapement.
Geneva Stripes: A form of decoration in higher grade watch movements which look like stripes on the movement plates. Also called Côtes de Genève.
Gilt: Gold plating
GMT: Greenwich Mean Time (GMT) is also known as Zulu Time and UTC (Universal Time Coordinated). The standard by which all World Time is set was agreed at the 1884 International Meridian Conference at Washington DC, USA. It placed Greenwich on the Prime Meridian (Zero Longitude). Greenwich Mean Time or GMT is the time standard against which all other time zones in the world are referenced. It is the same all year round and is not affected by Summer Time or Daylight Savings Time. Generally, when the GMT term is used with watches it refers to the ability of the watch that shows local time and the time in at least one other time zone in a 24-hour mode. The reason for showing the additional time zone in 24-hour mode is to allow the wearer to know if the second time zone is in AM or PM.
Gold filled/Rolled Gold Plate: This is a term used to describe early method of gold plating on watch cases and other watch parts (buckles, bracelets, etc.) A thin sheet of solid gold would be heated and pressed onto a base metal.
Gold Jewel Setting: In high grade watches the jewels were mounted in solid gold settings.
Gold Plated: A layer of gold that is plated onto a base metal case or bracelet to enhance its looks. The thickness of the plating is measured in microns (1000th of a mm).
Grande Complications: Describes a mechanical watch with an abundance of complications.
Guilloche: Guilloche/Engine Turning is an engraving technique in which a very precise intricate repetitive patterns or design is mechanically etched into an underlying material with very fine detail. Specifically, it involves a technique of engine turning, called guilloche in French, after the French engineer “Guillot”, who invented a machine that could scratch fine patterns and designs on metallic surfaces.
Hack/Hacking: Describes the feature of a movement whereby the seconds hand can be stopped for exact setting of the time. Usually done by pulling the crown out to its outermost position.
Hairspring: A very fine spring in a mechanical watch that causes the recoil of the balance wheel. The length and adjustment of its length regulate the watch’s timekeeping. It is also known as a balance spring.
Hallmark: Stamp indicating origin or metal content (gold, silver, platinum).
Hard Metal: A scratch-resistant metal created by binding titanium, tungsten carbide, and other materials and then pressing them into an extremely hard metal. A polish of diamond powder is used to add brilliance.
Helium Escape Valve: Professional Divers watches are designed with the needs of deep water divers in mind. These divers regularly spend extended periods of time in diving bells at pressure, breathing Hypoxic trimix or other mixed gases with helium in them. Because helium is such a small molecule (the second smallest there is), over time in a pressurized diving bell, helium will sneak its way past the o-rings into the inside of a dive watch. While at depth this causes no problem, it will as the divers decompress the helium which is unable to escape the watch. With a standard dive watch this would lead to the watch crystal popping out from internal pressure. To stop this happening, high-end, professional diver watches have a helium escape valve or helium bleed valve to let out this extra pressure during decompression. This is a one-way valve which allows the helium to escape.
Horology: The science of time measurement, including the art of designing and constructing timepieces.
Hunter/Hunting Case: Pocket watch case that completely encases the watch. Has a front cover and a back cover to protect the watch (while hunting).
Incabloc: Incabloc is a trade name for a type of shock absorbing device/spring used to protect the delicate parts of the mechanical watch escapement. Mentioned here as it is probably the most widely used and some watch manufacturers used to draw attention to it by referring to it on the watch dial itself.
Index Hour Marker: A simple stick/line design hour indicator on an analogue watch dial, used instead of numerals.
Integrated Bracelet: A watch bracelet that is incorporated into the design of the case.
Isochronism: Meaning the watch runs at the same rate whether the watch is fully wound, or only partially wound.
Jewels: Synthetic sapphires or rubies that act as bearings for gears in a mechanical watch. The jewels reduce friction to make the watch more accurate and longer lasting. Generally made of synthetic material, except for the precious or semi-precious stones (ruby, sapphire, garnet) which are sometimes used in deluxe watches.
Jump Hour/Minutes: A jump hour indicator takes the place of an hour hand. It shows the hour by means of a numeral in a window on the dial of the watch. The word “jump” refers to the fact that the numerals jump from 1 to 2 to 3, etc., rather than showing intermediate times between hours as hour hands do. The minutes and seconds in a jump hour watch are read as normal from the analogue hands and dial.
Kelek: Established in 1896 & now owned by Breitling. The name was changed to Breitling Chronometrie in 2002. The company decorates and modifies all of Breitling’s base movements for them as well as developing in-house modules. After their purchase we may see much more innovative horological additions to watches from Breitling.
Key Set: Watch that is set by means of a small key instead of by a crown. Earlier watches were key-set.
Kif: Another brand of shock absorbing device similar to Incabloc. Kif is probably the next most common shock absorber on the market.
Kinetic: In certain Seiko models, this refers to a technology that uses quartz movement without a battery. Instead, the watch is powered by the movement of the wearer’s wrist and can store power.
Lap Timer: A function in a chronograph watch that allows the wearer to time segments of a race. At the end of a lap, the timer is stopped and then returns to zero to begin timing the next segment.
Lever Escapement: The lever divides into two pallets which lock and unlock the escape wheel teeth. The action is governed by the balance engaging the other end of the lever, the escape teeth sliding on the inclined pallets life the lever to impulse the balance.
Lever Set: To avoid being set (incorrectly) by accident, Railroad watches were always lever set watches. This meant the conductor would need to remove the crystal and pull out a small lever in order to adjust the time. This was a serious safety measure to avoid train collisions.
Limited Editions: A style manufactured in a specific amount, often numbered, and available in limited quantities.
Liquid-Crystal Display (LCD): LCD watches show a numeric display continuously by means of the liquid held in a thin layer between two transparent plates. The numbers are made up of seven segments that form the number 8 when all are activated. They are activated by an electronic impulse.
Lug Width: Distance between the lugs which determines the size of strap or bracelet that the watch requires.
Lugs: Projections on a watch face to which the watch band or bracelet is attached.
Luminescence/Luminous: The emission of light produced by bioluminescence, fluorescence, phosphorescence, or other methods. On watches, some manufacturers use varying techniques to make the dial hands or other parts give off a low light.
Main Plate: The base plate upon which all other parts of a watch movement are mounted.
Mainspring: The driving spring of a watch or clock, contained in the barrel.
Manufacture: Short for “manufacture d’horologie”, this is a French horological term that is typically used to describe a company that fabricates all or most parts of the wristwatch and movement in-house rather than outsourcing.
Manual Wind Movement: A Manual watch operates by manually winding the crown which winds the mainspring in the barrel, thus powering the watch. Once wound it will stay working for the specified amount of time as indicated in your manual (generally 35-45 hours).
Marine Chronometer: A highly accurate mechanical or electronic timekeeper that is enclosed in a box and is used for determining the longitude on board a ship. Marine chronometers with mechanical movements are mounted on gimbals so they are in the horizontal position that is essential for their precision.
Measurement Conversion: A feature that allows the wearer to convert one type of measurement into another. It usually consists of a graduated scale on the bezel or dial.
Mechanical Movement: A “Mechanical Movement” is the term for watch that runs without an outside electrical source. The watch’s mechanism is composed of multiple parts, gears, screws and springs. By winding the mainspring (either manual-winding or via automatic winding) the watch will begin to operate.
Micrometric Regulator: Regulator that is finely tuned by the adjustment of a small screw. Used in high grade watches.
Micron: This is a thousandth of a millimetre and is a measurement used for the thickness of gold plating.
Military Time (24-hour time): Time measured in 24-hour segments; to convert 24-hour time to 12-hour time, simply subtract 12 from any number 13 or larger.
Mineral Crystal: Watch crystal made from what is essentially a form of glass. More scratch resistant than acrylic, a mineral crystal will however scratch and is extremely difficult to polish.
Minute Repeater: A watch that strikes the hours, quarters and minutes on gongs. The repeater is activated by a slide or button on the case edge. This is a highly complex achievement and increases the cost of the watch tremendously.
Mono (Single) Pusher Chronograph: A stop watch operated by a single button. While 99% of chronographs are operated by the use of two button – one to start and stop the stopwatch, the second to reset the stopwatch; a Mono Pusher complication allows for 1 button to start, stop and reset the stop-watch.
Moonphase Display: A window in a watch which indicates the phases of the moon through 29 1/2 days. Some Moonphase watches incorporate a correction for the extra 44 minutes per month.
Mother-of-Pearl: The iridescent interior of a freshwater mollusc that is often used to decorate watch dials. Its colours include milky white, blue and pink. Mother of Pearl is available in an array of colours, such as blue, pink, yellow and more.
Movement: The inner mechanism of a watch that keeps time and moves the watch’s hands calendar, etc. Movements are either mechanical or quartz.
Multi-Functional: Describes a quartz watch with extra features.
Numerals: Numeral (Roman and Arabic) are used to present information in the dial and sub dials.
Oil Sink: Recessed well around a pivot on a bridge that holds a small amount of oil to lubricate the motion of the arbor/gear.
Pair Case Watch: A Pocketwatch with that sits inside another protective case. The watch inside also having its own case. Hence pair case.
Pendant: The neck of a pocketwatch. This is where the crown is located and the bow is attached.
Perpetual Calendar: A complication showing the date, day, month and leap year cycle at the minimum. Many will also display the year and Moonphase. This watch will correctly adjust for short and long months as well as 29 days of February once in 4 years.
Plate: A watch has a front and a back plate. The internal parts are held between.
Platine: see Platinum
Platinum: Platinum is one of the rarest and most durable of precious metals. It doesn’t tarnish and has a radiant, beautiful white lustre. It is a popular choice for very prestigious watches and Limited Edition pieces.
Position: i.e. “adjusted 3 positions”. This term refers to the testing performed on a watch to determine its accuracy in different positions. There are 6 potential positions that a watch can be adjusted to perform under. They are Dial up, Dial Down, Stem up, Stem Down, Stem Left, Stem right.
Power Reserve: Energy stored to keep a watch running; the power reserve indicator shows how much power remains. Also called reserve de marche.
Power Reserve Indicator: An indication of the state of wind in the main spring. A hand on the dial points to the number of hours the movement will work before it runs down. Also known as Reserve de Marche.
Pulsimeter: A scale on a chronograph watch for measuring the pulse rate.
Pushers (Push Pieces): A button that is pressed to work a watch function such as a chronograph, alarm or date corrector.
Physical Vapor Deposition (PVD): A gold-coloured finish created with a coating of titanium nitrate covered by a coating of 22k gold.
Quartz Crystal: Quartz is a piezoelectric material, meaning that it generates an electrical charge when mechanical pressure is applied. These crystals also vibrate when a voltage from an outside source, such as a battery, is applied. Piezoelectricity was discovered by Pierre Curie and his brother Jacques in 1880. In the early 1920’s, W.G. Cady recognized that due to their elastic qualities, mechanical strength and durability, quartz crystals could be used to fabricate very stable resonators. Cady also concluded that the crystal could be cut in specific ways which would create resonators of almost any frequency that were practically independent of temperature variations. Quartz crystals were first used as a time standard by Warren Marrison, who invented the first quartz clock in 1927. Juergen Staudte invented a method for mass-producing quartz crystals for watches in the early 1970s.
Quartz Movement: This is an electronic watch movement with a quartz crystal that oscillates when a current is applied to it. The power to run the watch is normally provided by a battery or a capacitor. A quartz movement is generally more accurate than a mechanical movement.
Rattrapante Chronograph: The addition of a flyback hand (rattrapante) significantly increases the potential uses for chronographs. It makes possible the measurement of split second times or timing simultaneous events of unequal duration. Also known as Split Seconds Chronograph.
Regulator/Regulateur: A Regulator display separates the minute and hour hands onto a separate axial and sub-dial. This allows for accurate time telling at a glance without the chance of having the watch hands covering each other.
Rehaut: The flange or projection around the inner edge of the watch that typically holds the watch crystal up and reinforces it. The rehaut is typically referred to mostly on Rolex watches as they are inscribed for anti-counterfeiting measures. On most Breitling watches the rehaut is covered by an applied chapter ring.
Repeater: A device that chimes the time when the wearer pushes a button. Some repeaters, called “quarter repeaters” sound just the hours and the quarter hours (by means of two different pitched tones); others called “five minute repeaters”, sound the hours, quarters, and five minute periods after the quarter; and still others called “minute repeaters”, sound the hours, quarters and minutes.
Reserve de Marche: A feature that shows when the mainspring in the watch will need to be wound. This is a complication for mechanical watches that is quite useful and is usually indicated in hours, except in the case of watches that have a very high power reserve numbering in the days. Also known as Power Reserve Indicator.
Retrograde: A watch with a retrograde display does not display the function in a circular fashion, as we are used to seeing. Rather, it sets out the functions in a linear manner. Instead of the hands going round in a circle, they travel along an arc, and when they get to the end, they jump back to the beginning.
Rider Tabs: The four tabs located on the bezels of many of watches from Breitling such as the Chronomat Evolution and the SuperOcean. They are located on the 3, 6, 9 and 12 o’clock positions.
Roman Numerals: I,II,III,IV,V,VI,VII,VIII,IX,X,XI,XII
Rose (or Pink) Gold: A soft-hued gold with a higher concentration of copper in the alloy than yellow gold.
Rotating Bezel: A bezel (the ring surrounding the watch face) that can be turned. Different types of rotating bezels perform different timekeeping and mathematical functions.
Rotor: The part of an automatic (or self-winding) mechanical watch that winds the movement’s mainspring. It is a flat piece of metal, usually shaped like a semicircle, that swivels on a pivot with the motion of the wearer’s arm.
Sapphire Crystal: Sapphire crystal is a very hard transparent material commonly used for “scratch-proof” watch glasses. Made by crystallizing aluminium oxide at very high temperatures, it is chemically the same as natural sapphire and ruby, but without the small amounts of other elements such as iron, titanium or chromium that give the gemstones their colours. Sapphire (whether natural or synthetic) is one of the hardest substances, measuring 9 on the Mohs scale, a system for rating the relative scratch hardness of materials. (Diamond measures 10, the highest rating, and the hardest steels are 8).
Screw-Lock Crown (Screw-in Crown) (Screw-Down Crown): Where the crown is threaded and tightens to the case by screwing the crown into a matching threaded tube that is part of the case. The crown has a gasket that is compressed and seals the opening when the crown is tightened – thus ensuring water resistance. A Screw-Down Crown is an essential feature for any watch you intend on swimming with. An additional benefit of the Screw-Down Crown is that the crown is somewhat more protected from accidental knocks.
Second Time-Zone Indicator: An additional dial that can be set to the time in another time zone. This allows the wearer to know the time in two zones simultaneously.
Self-Winding (Automatic Winding): A watch with a mechanical movement that is wound by the motion of the wearer’s arm, not by turning the winding stem. If it’s not worn for a couple days, an automatic watch will need to be wound by hand to get it started again.
Shock Absorber: A watch with an “Incabloc” spring on the balance. This is a small spring which holds the balance staff jewel in place and prevents the delicate staff from breaking under shock.
Shock Resistance: A watch’s ability to withstand an impact equal to that of being dropped onto a wood floor from a height of 3 feet (as defined by U.S. government regulation.
Silveroid: Metal compound made to resemble silver.
Skeleton Case: A watch in which the case and various parts of the movement are of transparent material, enabling the main parts of the watch to be seen.
Slide Rule/Navigation Computer: A device, consisting of logarithmic or other scales on the outer edge of the watch face, that can be used to do mathematical calculations. One of the scales is marked on a rotating bezel, which can be slid against the stationary scale to make the calculations. Some watches have slide rules that allow specific calculations, such as for fuel consumption by an airplane or fuel weight.
Solar Compass: A compass that uses a rotating bezel to determine the geographical poles.
Solar Powered: Batteries in a quartz watch that are recharged via solar panels on the watch face.
Split Seconds Chronograph: A Chronograph with two centre seconds hands, the extra hand runs concurrently with the main chronograph hand but can be stopped independently then made to catch up with the running chronograph. Thus called the “Split Seconds hand” which refers to two hands – a flyback (Rattrapante) hand and a regular chronograph hand. Both hands move together with the ability to time laps or multiple finishing times, the wearer can stop the flyback hand while the chronograph hand continues. This, in effect, splits the hand in two. The split seconds thus allows recording the successive or additional times of events that start together.
Split Seconds Hand: Two watch hands: A flyback and a regular chronograph hand. When the chronograph is in use, both hands move together. To time laps or different finishing times, stop the flyback hand and the regular chronograph hand will keep moving, thereby splitting the hands.
Spring Bars (or Pins): Spring-loaded bars used to attach a strap or metal bracelet to a watch case.
Staff: The axle of the Balance
Stainless Steel: A durable metal alloy that is almost rust resistant and rarely corrodes or discolours and, therefore, is highly suitable for watch case and bracelets. It is sometimes used on the case backs of watches made of other metals.
Stepping Motor: The part of a quartz analogue movement that moves the gear train and in turn moves the watch’s hands.
Sterling Silver: Sterling silver refers to silver that is 92.5 percent pure, which should be stamped on the metal.
Stopwatch: A watch that measures intervals of time. When a standard watch has a stopwatch feature, that entire watch is called a chronograph.
Sub-dial/Subsidiary Dial: A small dial on the watch face used for any of several purposes, such as keeping track of elapsed minutes or hours on the chronograph, or indicating the date.
Swiss Made: A watch may only bear the Swiss-Made label if the assembly work of the movement and watch was started, adjusted and controlled by the manufacturer in Switzerland. Furthermore, the law requires that at least 50% of the components of the movement be manufactured in Switzerland. The case and bracelet must not be manufactured in Switzerland, however the parts must be delivered to Switzerland unassembled and be assembled in Switzerland.
Swiss A.O.S.C. (certificate of origin): A certificate of origin – a mark that identifies that a watch has been assembled in Switzerland and has components of Swiss origin.
Sweep Seconds Hand: Seconds hand mounted in the centre of the watch dial.
Tachymeter Scale(Tachometer): Common feature in chronograph watches. Measures the speed over a predefined distance. The wearer starts the chronograph when passing the starting point and stops it when passing the finish. The wearer can read the speed in units per hour off the tachometer scale. The scale is generally engraved on the bezel or printed on the outer diameter of the dial.
Tang Buckle: A tang buckle is a traditional Loop and Pin (belt type) buckle.
Tank Watch: A rectangular watch with bars along the sides of its face. It was inspired by the tracks of tank used in World War II and designed by Louis Cartier.
Telemeter: Determines the distance of an object from the person wearing the telemeter by measuring how long it takes sound to travel that distance.
30-Minute Recorder (or Register): A sub-dial on a chronograph that can time periods of up to 30 minutes.
Timer: A device for registering intervals of time without any indication of the time of day.
Titanium: A metal with a slightly darker/greyer appearance than Stainless Steel. Titanium is stronger and lighter than steel. Titanium is used increasingly in watch making, especially for sports and divers watches as it is resistant to salt water corrosion.
Tonneau Watch: A watch shaped like a barrel, with two convex sides.
Totalizer: A mechanism that keeps track of elapsed time and displays it, usually on a subdial on the watch dial. Same as a “recorder” or “register”. The term “totalizer” can be used more generally to refer to any counter on a watch.
Tourbillon: The Tourbillon compensates for differences in rate caused by a watch adopting different positions. The principle is to mount the balance and escapement in a rotating cage. The balance and escapement rotate around their common axis going through all positions to average out the errors, Tourbillon cages or platforms usually rotate once per minute but 4 minute and six minute tourbillons are also found. The Tourbillon complication is an extremely difficult accomplishment to achieve and generally demands a high premium.
Train: see Gear Train
Tritium: In tritium illuminations systems, such as those employed in Luminox watches, tritium gas is injected into glass tubes coated with a luminescent paint. The tritium gas excites the luminescent material, which will glow continuously for about 25 years without the need for exposure to light.
Two-Tone: Two metals combined, such as yellow gold and stainless steel, for a distinct look.
12-Hour Recorder (Register): A sub-dial on a chronograph that can time periods up to 12 hours.
Uni-Directional Rotating Bezel: A bezel that can be rotated in one direction only and is used to monitor elapsed time. A ratchet mechanism is often in place to prevent it rotating in the other direction. It is often found on divers watches to prevent the diver from running out of air by overestimating remaining air supply if the bezel is accidentally moved from the original position. The fact that the bezel moves in one direction only is a fail-safe feature which means the diver can only underestimate remaining air supply.
UTC: Universal Time Coordinated. A universal time based on the Greenwich Meridian used by the military and in aviation. Greenwich Mean Time (GMT) can be considered approximately equivalent to Universal Time Coordinated (UTC). GMT as such is now obsolete however, being replaced by UTC. Using this timezone/standard avoids errors and problems associated with different time zones and summer times operational in different countries.
VPH (Vibrations per Hour): 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.
Waterproof: No watch is fully 100 percent waterproof, and using the term waterproof is misleading and illegal.
Water Resistance: A watch that is water resistant can withstand water to a certain extent. Check the watch manual to find out the exact level of water resistance your watch is. The “Water Resistant” feature is common on most watches. It is important to remember that the water resistant rating is granted when the watch is new and tested in ideal conditions. As the watch ages the seals and gaskets begin to erode these ratings decline. Therefor it is necessary to have the water resistance tested every year.
White Gold: With a colour similar to silver or platinum, white gold is created by incorporating either nickel or palladium with yellow gold to achieve a white colour. Most watches made of white gold are 18k.
Winding: This is the action of tightening the mainspring of a watch. It can be done manually, by means of the crown, or automatically, via a rotor which is made to swing by the movement of the wearer’s wrist.
Winding Stem (Crown): The grooved button on the outside of the case, used for setting the hands of the watch and the day and date of where applicable. It is also used for winding the mainspring of a mechanical watch. It is also known as the crown.
World Time Dial/World Time Complication: A dial that tells the time of up to 24 time zones around the world. The names of the cities are printed on the dial. The hour in a particular zone can be read by looking at the scale next to the city that the hour hand is pointing to. The minutes are read in the normal way. The dial is usually found on the outer edge of the watch face. Watches with this function are called World Timers.
Yacht Timer: A countdown timer that sounds warning signals during the countdown to a boat race.
Yellow Gold: The traditional gold colour. Yellow gold used in watches is typically 14k or 18k.