WATCH TERMINOLOGY

12-hour recorder

A sub-dial on a chronograph that can time periods of up to 12 hours.

30-minute recorder

A sub-dial on a chronograph that can time periods of up to 30 minutes.

Alarm

A device that sounds a signal at a pre-set time.

Altimeter

A device that determines altitude by responding to changes in barometric pressure.

Analog display

A display that shows the time by means of hands and a dial.

Arabic Numerals

Numbers on a watch dial that are written the way we typically write numbers.

ATM (atmosphere)

One atmosphere equals 33 feet. 1 ATM = 33 feet or 10 meters. 3.3 feet = 1 meter.

Auto repeat countdown timer

A countdown timer that resets itself as soon as the pre-set time has elapsed and starts the countdown again. It repeats the countdown continuously until the wearer pushes the stop button.

Automatic winding

(Also called "self-winding") Winding that occurs through the motion of the wearer's arm rather than through turning the winding stem. It works by means of a rotor that turns in response to motion, thereby winding up the watch's mainspring. An automatic watch that is not worn for a day or two will wind down and will need to be wound by hand to get it started again.

Balance spring

A very fine spring (also called a "hair spring") in a mechanical watch that returns the balance wheel back to a neutral position.

Balance wheel

The part of a mechanical watch movement that oscillates, dividing time into equal segments.

Baton markers

Commonly referred to as stick markers, any straight-line marker used in place of numbers on a watch.

Battery

The power source of a quartz movement. A typical battery will last 12 to 18 months.

Battery reserve indicator

(also called end-of-life battery indicator) On a quartz watch it informs the wearer when the battery is low. Often this is indicated by the seconds hand moving at two or three-second intervals.

Beat

One complete oscillation of the balance wheel. Measured in beats per hour, the higher the frequency, the more accurate.

Bezel

The ring, usually made of gold, gold plate or steel that surrounds the watch face.

Bracelet

A type of watchband made of elements that resemble links.

Built-in illumination

Lighting on a watch dial that allows the wearer to read the time in the dark.

Calendar

A feature that shows the day of the month and often the day of the week and the year. There are several types of calendar watches. Some show the date and day of the week with sub-dials and analog hands.

Caliber

A watch movement.

Cambered

Often used in referring to a curved or arched dial or bezel.

Case

The metal housing of a watch's parts. Stainless steel is the most typical metal used but titanium, gold, silver and platinum can also be used.

Chronograph

A multifunction sport watch with a stopwatch function. Most have two or three sub-dials or mini-dials, for measuring minutes and hours.

Chronometer

A timepiece that has met certain high standards of accuracy set by an official watch institute in Switzerland.

Complication

Additional mechanism such as strike train, chronograph and calendar, which can be made by only a few specialists.

Countdown timer

A function that lets the wearer keep track of how much of a pre-set period of time has elapsed.

Crown

Button on the outside of the watch case that is used to set the time and the calendar and in a mechanical watch, to wind the mainspring. In the latter instance, it is also called a "winding stem."

Crystal

The transparent cover on a watch face made of glass, crystal, synthetic sapphire or plastic.

Day/night indicator

A colored or shaded band on a world time dial that shows which time zones are in daylight and which in darkness.

Deployant Buckle

Type of hinged watch buckle that may be used on a leather strap or bracelet.

Depth Alarm

An alarm on divers' watch that sounds when the wearer exceeds a pre-set depth. In most watches, it stops sounding when the diver ascends above that depth.

Dial

The face of a watch where the time is read.

Digital watch

A watch that shows the time through digits rather than through a dial and hands (analog) display.

Ebauche movement

A rare watch movement without jewels, escapement, plating or engraving.

Elapsed time rotating bezel

A graduated rotating bezel used to keep track of periods of time. The bezel can be turned so the wearer can align the zero on the bezel with the watch's seconds or minutes hand. The wearer can then read the elapsed time off the bezel.

Engine turning

Decorative engraving, usually on a watch face or parts.

Escapement

Device in a mechanical movement that controls the rotation of the wheels and thus the motion of the hands.

Etablisseur

A company which buys the major components and puts them together. Exhibition watch: Any watch that allows the wearer to view the movement. Usually the back only, but occasionally both front and back are visible.

Face

The visible side of the watch where the dial is contained. Most are printed with Arabic or roman numerals. Note: Traditionally IIII, rather than IV, is used to indicate the 4 o'clock position.

Fluted bezel

A type of grooved, high polish bezel.

Fly-back hand

A second's hand on a chronograph that is used to determine lap or finishing times for several competitors. To operate, put both the flyback and the regular second hand in motion; then to record a lap or finish time, the flyback hand can be stopped. After taking the results, push a button and the flyback hand will catch up to the constantly moving second hand.

GMT

(Greenwich Mean Time) A watch that keeps track of two or more time zones, usually with an extra hour hand that travels once around the dial every 24 hours, and is read on the bezel rather than the dial.

Galbee

The formal name of a watch with a curved case and movement. Sometimes called curvex.

Gear train

The system of gears, which transmits power from the mainspring to the escapement.

Grande sonnerie

A type of repeater that sounds the hours and quarter hours when the wearer pushes a button.

Guilloche

A type of engraving, in which thin lines are interwoven, creating a patterned surface. It is often used on dials.

Hands

The parts of any analog watch that point to the hour, minute or seconds markers. The most common types of hands are sword, baton, dauphine and brueget.

Horology

The science of time measurement, including the art of designing and construction timepieces.

Index

The hour indicator on an analog watch, used instead of numerals. (Also referred to as markers.)

Integrated bracelet

A watch bracelet that is incorporated into the design of the case.

Jewels

Synthetic sapphires or rubies that act as bearings for gears in a mechanical watch, reducing friction. A quality hand-wound or automatic mechanical timepiece contains at least 17 jewels.

Jump hour indicator

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 watch face.

No terms

Lap memory

The ability, in some quartz sport watches, to preserve in the watch's memory the times of laps in a race that have been determined by the lap timer. The wearer can recall these times on a digital display by pushing a button.

Lap timer

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.

Leap Year indicator

Usually in perpetual calendar watches, this tells the wearer when it is leap year. The most common execution of this complication is to show the Roman numeral I, II, III or IV in a window with IV representing the leap year.

Liquid-crystal display

(LCD) A digital watch display that shows the time electronically by means of liquid held in a thin layer between two transparent plates. All LCD watches have quartz movements.

Lugs

Extensions on either side of the bezel where the bracelet or strap is attached.

Mainspring

The power source of a mechanical watch. A long strip of metal that drives the movement with the energy of its uncoiling.

Manual Wind

The simplest type of mechanical movement. The wearer manually rewinding the crown maintains the mainspring tension. It is best for the watch to be wound at the same time each day.

Manufacturer

A company that designs and makes entire watches.

Mechanical movement

A movement powered by a mainspring, working in conjunction with a balance wheel (as opposed to a battery and quartz crystal).

Mineral crystal

A heat or chemical treated type of glass crystal. Generally, these cannot be polished.

Minute repeater

A complication on a watch that can strike the time in hours, quarters, or seconds by means of a push piece. The first complication invented, before electricity, was in 1687 by Daniel Quare to enable the wearer to tell time in the dark. Moon phase: A window in a watch face that shows which phase the moon is in. A disk beneath the window, painted with two pictures of a moon, rotates as the month progresses, revealing gradually larger or smaller segments of the picture.

Movement

The inner mechanism of a watch that keeps time and moves the watch's hands, calendar, etc. Movements are either mechanical or quartz.