Watch Knowledge

12-hour (24-hour) recorder (or register)

A sub-dial on a chronograph (see chronograph) that can time periods of up to 12 or 24 hours.

30-minute recorder (or register)

A sub-dial on a chronograph (see “chronograph”) that can time periods of up to 30 minutes.

Alarm

The watch alerts you with beeps at a pre-set time.

Analog

A watch that shows the time using hour and minute hands.

Analog - digital display

A watch that shows the time by means of hour and minute hands (analog display) as well as by numbers (a digital display).

Anti-magnetic

The movement of a mechanical watch can be thrown off balance if it comes in contact with a strong magnetic field; Magnetism is common in loudspeakers, televisions, refrigerators, cars, etc. etc. and these days most watches claim to be anti-magnetic. This is achieved by using alloys for certain parts, among them the balance wheel and escape wheel. Electronic watches are not susceptible to magnetism.

Automatic winding

(or self-winding) 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 of the wearer’s arm rather than through turning the winding stem. A rotor that turns in response to motion winds the watch’s mainspring. If an automatic watch is not worn for a day or two, it will wind down and need to be wound by hand to get it started again.

Battery reserve indicator (or end of battery indicator)

Some battery operated watches have a feature that indicates when the battery is approaching the end of its life. This is often indicated by the second hand moving in two second intervals instead of each second.

Bezel

The ring which surrounds the watch dial (or face). The bezel is usually made of gold, gold plate or stainless steel.

Bi-directional rotating bezel

A bezel that can be rotated either clockwise or counterclockwise. These are used for mathematical calculations such as average speed or distance (see “slide rule”) or for keeping track of elapsed time(see “elapsed time rotating bezel”).

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 shoe the information on sub-dials on the watch face.

Case materials

Materials range from inexpensive cast metal through moulded plastic to solid chunks of steel or gold from which the case is machined. In Great Britain, gold cases are usually 18k, but less expensive watches are 9k. In most other countries, 14k is preferred. Caratage indicates the gold content of metal, stated as the number of parts of gold in every 24 parts, i.e. 18k gold is 18 parts of gold alloyed with six parts of metal. Platinum is becoming increasingly popular, as is titanium for its lightness. Ceramic cases and bracelets -a scratch resistant space age material formed under great pressure and heat from powder -are used by some manufacturers. It does not bear any resemblance to the ceramics used in pottery. Some watches in the middle price ranges are gold plated over brass -9k or 18k plating usually. Vermeil is the term used to describe silver which has been gold plated.

Cases

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. A watch case is generally in 3 parts -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.

Chronograph

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 variations on the chronograph. Some operate with a center seconds hand which keeps time on the watch’s main dial. Others use sub-dials to time elapsed hours, minutes and seconds. Still others show elapsed time on a digital display on the watch face. Some chronographs can be used as a lap timer (see “flyback hand” and “split seconds hand”). The accuracy of the stopwatch function will commonly vary from 1/5th second to 1/100th second depending on the chronograph. Some chronographs will measure elapsed time up to 24 hours. Watches that include the chronograph function are themselves called “chronographs.” When a chronograph is used in conjunction with specialized scales on the watch face it can perform many different functions, such as determining speed or distance (see “tachymeter” and “telemeter”) Do not confuse the term “chronograph” with “chronometer.” The latter refers to a timepiece, which may or may not have a chronograph function, that has met certain high standards of accuracy set by an official watch institute in Switzerland.

Complications

One or more features added to a watch in addition to its usual time-telling functions, which normally not only include the hours, minutes and seconds but also date and often the day of the week as well. Complications such as; perpetual calendars, moonphase displays, alarms, repeating mechanisms, quarter strikes as well as stop/start chronograph functions. Power reserve indicators are also usually regarded as ‘complications’.

Countdown timer

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 warning signal a few seconds before the time runs out. These are useful in events such as yacht races, where the sailor must maneuver the boat into position before the start of a race.

Crown

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 crown also winds the mainspring. In this case it is also called a “winding stem”. A screw in (or screw down) crown is used to make a watch more water resistant. The crown actually screws into the case, dramatically increasing the water-tightness of the watch.

Crystal

The transparent cover on a watch face made of glass crystal, synthetic sapphire or plastic. Better watches often have a sapphire crystal which is highly resistant to scratching or shattering.

Dial

The watch face.

Digital watch

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

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 on the bezel with the watch’s seconds or minutes hand. After a period of time passes, you can read the elapsed time off the bezel. This saves you having to perform the subtraction that would be necessary if you used the watch’s regular dial.

Escapement

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

Flyback hand

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 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.

Gold plated

A layer of gold electroplated to a base metal.

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.

Jumping hours

A digital display where the time in hours is shown in the dial as a number, usually visible through an aperture. The number changes, or jumps, precisely on every hour.

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.

Mechanical movement

A movement powered by a mainspring, working in conjunction with a balance wheel. Most watches today have electronically controlled quartz movements and are powered by a battery. However, mechanical watches are currently enjoying a resurgence in popularity.

Moonphase display

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 in between. Very popular in the 90’s but losing favour in the second half of the century.

Movement

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

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 when the battery is low. Often this is indicated by the seconds hand moving at two or three-second intervals. Seiko’s Kinetic watches are quartz watches that do not have a battery (see Kinetic). When a Seiko Kinetic needs to be wound, the seconds hand will also move in two second intervals.

Pushers or push pieces

Push buttons are on the case of the chronographs and some complicated watches. Most are used to stop and start a stopwatch but sometimes serve other functions.

Quartz movement

A movement powered by a quartz crystal to. Quartz crystals are very accurate. They can be mass produced which makes them less expensive than most mechanical movements which require a higher degree craftsmanship.

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 (see elapsed time rotating bezel,” “unidirectional rotating bezel,” “bi-directional rotating bezel” and “slide rule.”)

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

A crystal made of synthetic sapphire, a transparent, shatter-resistant, scratch-resistant substance.

Screw-lock crown

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.

Stopwatch

A watch with a seconds hand that measures intervals of time. When a stopwatch is incorporated into a standard watch, both the stopwatch function and the timepiece are referred to as a chronograph.

Sub-dial

A small dial on a watch face used for any of several purposes, such as keeping track of elapsed minutes or hours on a chronograph or indicating the date.

Tachymeter

(“tack IM eh ter”) A feature found on some chronograph watches, a tachymeter (also called a “tachometer”) measures the speed at which the wearer has traveled over a measured distance.

Telemeter

(“tel EH meh ter”): A telemeter determines the distance of an object from the observer by measuring how long it takes sound to travel that distance. Like a tachymeter (see “tachymeter”), it consists of a stopwatch, or chronograph, and a special scale, usually on the outermost edge of the watch face.

Titanium

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.

Tonneau watch

A watch shaped like a barrel, with two convex sides.

Uni-directional rotating bezel

An elapsed time rotating bezel (see “elapsed time rotating bezel”), often found on divers’ watches, that moves only in a counterclockwise direction. It is designed to prevent a diver who has unwittingly knocked the bezel off its original position from overestimating his remaining air supply. Because the bezel moves in only one direction, the diver can err only on the side of safety when timing his dive. Many divers’ watches are ratcheted, so that they lock into place for greater safety.

Water resistance

The ability to withstand splashes of water. Terms such as “water resistant to 50 meters” or “water resistant to 200 meters” indicate that the watch can be worn underwater to various depths.