Watch your language
Riddle’s in-house expert begins his guide to the occasionally baffling world of watch terminology – starting with A-F
Article by John Galt
Altimeter: A device that determines altitude by responding to changes in barometric pressure much like an altimeter gauge in an airplane cockpit, mostly used for pilots while flying, with Breitling watches being one of the best.
Analog Watch: A piece with a conventional dial made up of hands, numbers or markers that present a total display of 12-hour time span. Analog digital refers to a watch that has both a digital display and hands of a conventional watch.
Aperture: Small opening on the dials of watches in which certain indications are shown (e.g. the date, the hour, day etc).
Automatic Movement: A mechanical movement that requires no manual winding because the rotor, part of the automatic mechanism, winds the mainspring every time you move your hand. The first automatic movement was invented in Switzerland by Abraham-Louis Perrelet in the 18th century. When fully wound and left to sit, most automatics have up to two days of reserve power before they will need winding again to start.
Automatic Winding (also see Automatic movement): The 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 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, historically made from metal but with recent technological breakthroughs we are seeing some made from silicon or plastic.
Balance Wheel: The part of a mechanical watch movement that oscillates, dividing time into equal segments.
Bezel: The outer ring of the watch that surrounds the watch face. Made in wide range of materials including gold, steel and ceramic with many possible colours.
Bi-directional Rotating Bezel: A bezel that can be moved either clockwise or counterclockwise. These are used predominantly for keeping track of elapsed time.
Bracelet: A metal watch strap made up of links held together with either screws or pins.
Bridge: Complementary part fixed to the main plate to form the frame of a watch movement. The other parts are mounted inside the frame.
Calendar: The calendar feature shows the day of the month, but often can also show day of the week, month and the year. There are several types of calendar watches.
Caliber: A term often used by Swiss watchmakers to denote a particular model type, such as Caliber 48 meaning model 48. But more commonly the term is used to indicate the movement’s shape, layout, or size.
Case: The metal housing containing a watch’s working parts. Stainless steel is the most widely metal used but titanium, gold, silver, and platinum is also used. Less expensive watches are usually made of brass and plated with gold or plastic.
Caseback: The reverse side of a watch case that lies against the skin. They can be transparent to allow viewing of the inner workings which are called an exhibition caseback or be solid. Most manufacturers engrave caseback with their name, water resistance and case serial numbers.
Chronograph: A timer that can be started and stopped to time an event. There are many variations of the chronograph. Some operate with a center seconds hand which keeps time on the watch’s main dial. Others use subdials to elapsed hours, minutes and seconds. When a chronograph is used in conjunction with specialized scales on the watch face, it can show many more functions, such as determining speed or distance.
Chronometer: This term refers to a precision watch that is tested in various temperatures and positions, thus meeting the accuracy standards set by an official institute in Switzerland. Most watch companies provide a certificate with your chronometer purchase.
Complication: A watch with other functions besides just telling the time. For example, a chronograph is a watch complication. Other complications coveted by watch collectors include: minute repeater, tourbillon, perpetual calendar, or split second chronograph.
COSC (Contrôle Officiel Suisse des Chronomètres): The official Swiss Chronometer Testing Institute that puts every chronometer watch through a rigorous, 15-day testing procedure to verify the watch’s precision.
Crown: Button on the outside of the case that is used to set the time and the calendar, and with hand wound or mechanical watches used to wind the mainspring.
Crystal: Transparent cover on the watch face made of glass crystal, synthetic sapphire or plastic.
Day/Date Watch: A watch that indicates not only the date but also the day of the week.
Day/Night Indicator: A coloured or shaded band on a world time that shows which time zones are in daylight and which in darkness.
Dial: The face of the watch. For high-end watches the numerals, indices and surface designs are applied, whereas less expensive watches they usually printed on the dial.
Dual Timer or GMT: Measures current time as well as at least one other time zone. The additional time element may come from a twin dial, extra hand, subdials, or other means.
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 minute’s hand. Used frequently on diving watches
Escapement: Device in a mechanical movement that controls the rotation of the wheels and thus the motion of the hands.
ETA: One of the leading manufacturers of watch movements based in Switzerland. ETA movements are used by many major watch brands either as a complete movement or watch brands may modify it to their own specification
Flyback hand: A seconds hand on the chronograph that can be used to time laps or to determine finishing times for several competitors in race at the same time. Normally found as a large center second hand.
Fluid: Normally a definite no no with watches as fluid would ruin a movement but one Watch Company is now using colored fluid to tell the time.