A watch provided with a movement capable of releasing an acoustic sound at a pre-set time.
Combination of two or more pure molten metals. Generally, an alloy is given the name of the dominant metal.
A device that determines altitude by responding to changes in barometric pressure.
Analog or Analogue
A watch that shows the time using hour and minute hands; as compared to a watch with a digital or numeric display.
An Annual Calendar complication displays the day, date and month with the need for manual adjustment only in February to account for leap years.
The movement of a mechanical watch can be thrown off balance if it comes in contact with a strong magnetic field; Magnetism is common
A small opening in the dial. In an aperture watch, various indications such as the month, moon phase, day, date, hour, minute, etc. are visible through these openings.
Numbers – e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12; as compared to Roman Numerals I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII.
The axle of a wheel or gear that turns in a bearing or jewel; e.g. barrel arbor, winding arbor, pallet arbor, etc.
The watch can receive signals from six atomic clock radio broadcasts worldwide providing unerring timekeeping. The U.S. government
This term refers to a watch with a mechanical movement (as opposed to a quartz or electrical movement). The watch is wound by the motion
Ladies style watch with a thin, elongated face; usually rectangular in shape but may be oval.
This is essentially and oscillator which regulates the speed of the movement of a
An extremely delicate coil-like spring, moving the balance back and forth.
Similar to a clock pendulum, the balance wheel oscillates to split time into equal segments.
A cylindrical shape containing the mainspring of a timepiece.
A device that transform the energy created by a chemical reaction into electrical energy.
Typically, a battery lasts for two to five years. Its lifespan will depend on the type of watch, its size and the amount of energy required for the different functions. A chronograph will consume more energy than a watch that shows only hours, minutes and seconds.
Special lithium-iodine batteries have a theoretical lifespan of 10 years.
Battery Reserve Indicator
Some battery operated watches have a feature that indicates when the battery is approaching
A feature found on some watches, measures the atmospheric pressure.
The ring surrounding the watch face, often decorated or adorned with hour markers or a tachymetric scale.
A bezel that can be rotated either clockwise or counterclockwise. These are used for
Lighting on a watch dial that allows the wearer to read the time in the dark.
Usually matching the case, it attaches the two parts of the leather strap around the wrist.
Variously-shaped ring for suspending a pocket watch and fastening a chain.
Lighting on a watch dial that allows the wearer to read the time in the dark.
Decorative stone which has been carved into a round shape.
A feature that shows the date, and often the day of the week. There are several types of calendar
The horological term for a watch movement, these can be mechanical or quartz.
The case of a watch must not only protect the mechanism and hold all the parts together but it must also look good sometimes to the extent of making a timepiece into a piece of jewellery.
the bezel, which holds the crystal,
the band or centrepart, which contains the movement,
and the back, either snapped or screwed on, in to which, sometimes, is fitted a crystal so that an intricate mechanical movement watch
The reverse side of a timepiece. This can be covered, perhaps with engraving, or sapphire to be able to view the inner workings of the timepiece.
Materials range from inexpensive cast metal through molded plastic to solid chunks of steel or gold from which the case is machined. In Great Britain, gold cases are usually 18k,
Seconds indicated by a hand at the centre of the dial, along with the hour and minute hands.
From the Greek keramos meaning fired pottery. In watchmaking, ceramic is a high-
tech material, generally made from aluminium
The ring on the watch dial bearing figures and minute marks. The hour figures are sometimes called chapters
A watch that includes a built in stopwatch function – i.e., a timer that can be started and stopped to time an event. There are many
Technically speaking, all watches are chronometers. But for a Swiss made watch to be called a chronometer, it must meet certain
The attachment used to connect the two ends of the watch bracelet or strap around the wrist.
There are a number of clasp types commonly
Deployment Buckle: (also known as a fold-over buckle): Three-folding closure that secures two ends of a bracelet. When closed, the buckle covers the folding mechanism.
Push-Button Foldover Clasp With Safety: is a deployment clasp with a push-button mechanism that opens the bracelet, along with a fold over closure on top that provides a second layer of security.
Hidden Clasp: (also called butterfly clasp): Folds the sections under the watch band to make the bracelet appear as an uninterrupted chain.
Tang or Buckle Clasp: A buckle with a hook, the tang that fits into a hole on the watch strap
Jewelry Clasp: A hinged hook that folds over a bar to secure the watch band.
A timepiece dial where it is not possible to see through into the inner workings of the timepiece.
Is a type of modern watch escapement mechanism invented by English watchmaker George Daniels. Considered by many to be one
A compass that lets the wearer determine the geographical poles by means of a rotating bezel. The wearer places the watch so that
A Complete Calendar complication displays the day, date and month with the need for manual adjustment at the end of each month not 31 days long.
A complication is any further function on a timepiece beyond the keeping of regular time. For example, each of the following would be classed as a complication: date display, power
The skeleton of a marine animal. Coral polyps secrete a strong calcium structure that was often used for watch dials. It s colour ranges from pale pink (called angelskin coral) to
A Swiss standard of quality certification. An acronym for Controle Officiel Suisse des Chronometeres.
The cosmograph differs to the chronograph in that the tachymeter is on the bezel rather than on the outer rim of the dial. This was invented
A function that lets the wearer keep track of how much of a pre-set period of time has elapsed. Some countdown timers sound a
Also called a stem or pin, a crown is the button on the outside of the watch case that is used to set the time and date. In a mechanical watch
The transparent cover on a watch face made of mineral glass crystal, synthetic sapphire or plastic. Better watches often have a sapphire
A wide, tapered hand with a facet at the center running the length of the hand.
A colored or shaded band on a world time that shows which time zones are in daylight and which in darkness.
An alarm on a divers’ watch that sounds when the wearer exceeds a pre-set depth.
A device on a divers’ watch that determines the wearer’s depth by measuring water pressure. It shows the depth either by analog hands and a
The face of a timepiece. Some dials have within them smaller dials for displaying the date, etc, called “subsidiary” dials, or “subdials.”
A watch that shows the time through digits rather than through a dial and hands (analog) display.
Diamond is the hardest and most luminous precious stone. The price of a diamond is calculated according to the 4C criteria: Cut –
Diver’s watches are designed and manufactured especially for divers whose lives depend on the reliability of their watch in the
A dress watch is an elegantly designed timepiece with a restrained and classy aesthetic, suitable for a black-tie event.
A watch that measures current local time as well as at least one other time zone. The additional time element may come from a twin
A dual, or multiple time-zone timepiece allows simultaneous display of the time in different time-zones.
Elapsed Time Rotating Bezel
A graduated rotating bezel (see rotating bezel”) used to keep track of elapsed time. The bezel can be turned so the wearer can align the zero
Electronic (Quartz) Watch
A watch, usually battery-powered, which uses an electric current to cause a quartz oscillator to vibrate, normally 32,768 Hz per second but
The saturated green variety of the Beryl family. Its color is due to minute traces of chromium or sometimes vanadium. Emeralds have a
A colored or transparent layer of vitreous material (i.e. a special type of glass) which protects or decorates its metal substrate.
The part of a mechanical calibre which controls the rotation of the wheels and motion of the hands.
A specific type of chronograph where the ‘stop’, ‘reset’ and ‘start’ functions can performed with a single push, used for recording lap times.
A seconds hand on a chronograph that can be used to time laps or to determine finishing times for several competitors in a race. Start
The ability of certain gemstones to transform invisible light (ultra violet light) into visible light (see Luminescence). Fluorite is such a mineral.
Fluting is a decorative design feature often found on the bezel or sides of a casing.
The system of gears which transmits power from the mainspring to the escapement.
Gold has seduced the world with its beauty, but also because not even acid can alter its natural
Contains: For 750 gold, approximately:
- Yellow gold: 12.5% silver – 75% pure gold – 12.5% copper
- Pink gold: 6% silver – 19% copper – 60% pure gold – 10% palladium – 5% nickel
- Red gold: 5.5 % copper – 94.5% pure gold
- White gold: 10% copper – 10% palladium – 5% nickel – 75% pure gold
- Blue gold: an alloy of gold and iron. Heat treatment oxidizes the iron molecules at the surface of the metal, producing the blue color.
- Green gold: an alloy of gold, silver and copper.
- Black gold: obtained by means of chemical vapor deposition (similar to PVD) of atoms of gold, carbon and other metals. The black coating is just a few microns thick. Other surface treatments use electrodeposition of rhodium, chromium and very dark impurities.
- Brown gold: obtained by heat treatment.
Gold Plated (Gilt)
A layer of gold electroplated to a base metal.
The most complex of mechanical watches featuring an abundance of complications.The
A type of repeater that sounds the hours and quarter hours when the wearer pushes the button.
A type of engraving in which thin lines are interwoven, creating a patterned surface.
A timepiece with a calibre which is hand-wound does not require a battery, however it does require the wearer to wind it manually to work.
A scratch resistant metal comprised of binding several materials, including titanium and tungsten carbide, which are then pressed
Helium Escape Valve
Helium Escape Valve
The art and/or science of measuring time and exploring timepieces.
That part of a watch case to which the strap is attached. Horns come in various shapes and are attached to the case middle.
A watch whose case has a front and back cover.
The jewel-pin that serves as the point of contact between the time-train and the balance wheel. Also called the roller jewel.
A shock-absorber brand used in mechanical watches which helps prevent damage from shocks to the balance pivots. Kif is another well-known brand.
A watch bracelet that is incorporated into the design of the case.
Synthetic sapphires or rubies that act as bearings for gears in a mechanical watch.
The jewels reduce friction to make the watch
System of timekeeping whereby the seconds and minutes are shown by traditional hands but the hour is shown in a dial cutout (often at
Karat or K
An indication of the purity of the metal used, expressed in the number of 1/24th of the pure metal used in the alloy. Metals such as gold are
Refers to the Seiko line of Kinetic watches. This innovative technology has a quartz movement that does not use a battery. Movement of your
A chronograph function that lets the wearer time segments of a race. At the end of a lap, he stops the timer, which then returns to zero to begin timing the next lap.
Light Emitting Diode (LED)
A digital watch display showing time at the push of a button.
Liquid-Crystal Display (LCD)
A digital watch display that shows the time electronically by means of a liquid held in a thin layer between two transparent plates. All LCD watches have quartz movements.
Projections on a watch face to which the watch band or bracelet is attached.
Hands made of skeleton form with the opening filled by a luminous material.
Luminous dials first appeared during the Great War when soldiers needed to tell the time in the
A new-generation luminous substance, used to coat hands and numerals. It stores light which
This spring is wound to store energy which is subsequently used to power a mechanical watch. This can be wound automatically or
A hand-wound mechanical watch. Wound by turning the crown back and forth until resistance is met.
A manufacture is the term used for a watchmaking company which makes every part of their timepieces in-house.
Highly accurate mechanical or electronic timekeeper enclosed in a box (hence the term box chronometer), used for determining the longitude on board ship. Marine chronometers
Markers are indications on the dial for each hour point. These can be batons, circles, lines, diamonds, or others depending on the design of the timepiece.
A feature, usually consisting of a graduated scale on the watch’s bezel, that lets the wearer translate one type of measurement into another-miles into kilometers, for instance, or
A timepiece with a calibre which is mechanical does not require a battery. Mechanical watches can be either manual/hand-wound or automatic.
A complication where at a specific time, the timepiece will sound an alarm to indicate the time is that set.
A movement powered by a mainspring, working in conjunction with a balance wheel. Most watches today have electronically controlled
A minute repeater complication is a high-end mechanical complication, where upon sliding a switch on the side of the timepiece case, the
A graphic display by means of a specially shaped aperture in the dial to indicate the phase of the moon, i.e. full, new or somewhere
Mother of Pearl
A smooth, shining material incorporated onto the dials of some timepieces, commonly found in the shells of molluscs such as Oysters.
The inner mechanism of a watch that keeps time and moves the watch’s hands, calendar, etc. Movements are either mechanical or quartz.
A natural pearl is also called an oriental pearl. This pearl is formed by an oyster, reshwater mussel or other mollusc as a reaction to a tiny
Describes a substance produced by a living organism. Pearl, coral and shell are examples of organic substances used in jewellery.
A timepiece dial where either part or all of the inner workings of the timepiece or visible from the front.
A device that counts the number of strides taken by the wearer by responding to the impact of the wearer’s steps.
A Perpetual Calendar complication displays the day, date and month with no need for manual adjustment, years, until a leap including leap
One of the rarest precious metals, platinum is also one of the strongest and heaviest, making it a popular choice for
A synthetic resin that can be used for watch crystal.
Poinçon de Genève (LED)
The Poinçon de Genève is a certificate awarded to timepieces with impeccable finishing and detail, an independent Swiss certification
Power Reserve Indicator
A feature that shows when the watch will soon need a new battery or winding. A battery reserve indicator on a quartz watch informs the wearer
The button on the side of a timepiece to control a chronograph.
Physical Vapour Deposition (PVD)
A coating of titanium nitrate applied in a vacuum and then covered by a coating of 22k gold to obtain a gold colored finish.
A timepiece with a calibre which is battery powered and does not require any manual or automatic winding.
In the 1970s and 1980s, the invention of cheaper quartz timepieces had a huge detrimental effect on mechanical watchmaking. This period is known as the quartz crisis.
A movement powered by a quartz crystal to. Quartz crystals are very accurate. They can be mass produced which makes them less
Used to describe the split seconds chronograph (see Flyback) which has two seconds hands sitting atop one another. On depression of a
Numbers displayed in Roman convention e.g. I, II, III, IIII*, V, VI, VII, VIII, IX, X, XI, XII.
*Note the use of “the watchmakers’ four”, using
Rose (or pink) Gold
A softly hued gold that contains the same metals as yellow gold but with a higher concentration of copper in the alloy. A popular
A bezel (the ring surrounding the watch face) that can be turned. Different types of rotating bezels perform different timekeeping and
The part of an automatic (or self-winding) mechanical watch that winds the movement’s mainspring. It is a flat piece of metal, usually
A crystal made of synthetic sapphire, a transparent, shatter-resistant, scratch-resistant (9 on the Moh scale) substance.
A crown that can be screwed into the case to make the watch watertight.
Second Time-zone Indicator
An additional dial that can be set to the time in another time zone. It lets the wearer keep track of local time and the time in another country simultaneously.
A self-winding timepiece has a calibre wound automatically by the wearer’s everyday movements by use of a rotor.
A timepiece dial where either part or all of the inner workings of the timepiece or visible from the front.
A watch with no dial and only a chapter ring. As much metal is removed as possible and all the remaining parts are decorated with elaborate engravings.
A feature made famous by Breitling’s Navitimer, allowing the wearer to perform logarithmic calculations by rotating the bezel.
A watch that uses solar energy (from any light source) to power the quartz movement.The Citizen >Solar-Tech< models use this
Spring Bars (or Pins)
Spring-loaded bars between the lugs on the case, used to attach a strap or metal bracelet to the case.
The part of a quartz movement that moves the gear train, which in turn moves the watch’s hands.
A white and highly reflective precious metal. Sterling silver refers to silver that is 92.5 percent pure, which should be stamped
Watches usually come fitted with either leather or rubber straps that close with a buckle or clasp, or a steel bracelet, that also secures with
A watch with a seconds hand that measures intervals of time. When a stopwatch is incorporated into a standard watch, both the
A small dial on a watch face used for any of several purposes, such as keeping track of elapsed minutes or
As a part of a move towards greater consumer protection and in order to combat fakes in the Far East that claim to be swiss made, the Swiss
A scale used on the bezel of a chronograph allowing the wearer to calculate a constant speed. If starting and stopping the
A rectangular watch designed by Louis Cartier. The bars along the sides of the watch were inspired by the tracks of tanks used in World War 1.
A telemeter determines the distance of an object from the observer by measuring how long it takes sound to travel that distance. Like
A feature found on some watches, measures the temperature.
A metal that is used for some watch cases and bracelets. Titanium is much stronger and lighter than stainless steel. Titanium is also hypo-allergenic.
A watch shaped like a barrel, with two convex sides.
A device, invented by Breguet in 1801, in which the escapement is mounted in a small revolving cage as a means of overcoming the
Uni-Directional Rotating Bezel
An elapsed time rotating bezel, often found on divers’ watches, that moves only in a counterclockwise direction. It is designed to
Movement of a pendulum or oscillating body between two extreme positions. The balance of a mechanical watch generally makes five
A quartz watch makes 64,000 vibrations per second ( 32 MHz).
An oscillation (“tick-tock”) equals two vibrations (although oscillation is sometimes incorrectly used to refer to a vibration).
The ability to withstand splashes of water. Terms such as “water resistant to 50 meters” or “water resistant to 200 meters” indicate that
Water Resistant – light rain or hand washing, but should not be used while swimming or diving.
Water Resistant to 50M (165Ft.) – Suitable for showering or shallow water swimming
Water Resistant to 100M (330Ft.) – Suitable for swimming or snorkeling.
Water Resistant to 150M (500Ft.) – Suitable for snorkeling.
Water Resistant to 200M (660Ft.) – Suitable for skin diving.
Sometimes water-resistance is measured in atmospheres (ATM). An ATM is equal to 10M of water pressure.
The button on the right side of the watch case used to wind the mainspring. Also called a “crown.”
World Time Dial
A dial, usually on the outer edge of the watch face, that tells the time in up to 24 time zones around the world. The time zones are
A countdown timer (see “countdown timer”) that sounds warning signals during the countdown to a boat race.
The traditionally popular gold used in all gold, gold and stainless steel, or other precious metal combinations. Yellow gold watches may
Small additional dial or indicator that may be positioned, or placed off-center on the main dial, used for the display of various functions (e.g. second counters).
Circular belt with the ecliptic in the middle containing the twelve constellations through which the sun seems to pass in the course of a year.