Glossary of Important Watch Terms
If you are new to the world of horology, it can sometimes be a bit overwhelming to keep up with the long-time watch enthusiasts. You want to be able to join in on the conversation, but you don’t know what all of the watch terms mean! Here are some of the terms that will most likely come up in a conversation regarding a luxury watch:
Analog: a watch that tells the time using both minute and hour hands.
Annual Calendar: A complication that shows the day, date, month, and often times, the moonphase. An annual calendar is able to adjust for short and long months (except for February). Annual calendars must be adjusted once a year.
Automatic watch: Invented in the 18th century, an automatic watch is a watch that is wound simply by the movements in the wearer’s arm motion. The weighted rotor is attached to the movement and spins when the watch is put in motion by the wearer’s physical activity.
Balance: As one of the most important parts of a watch, it keeps the watch accurate. Usually circular, the balance wheel, or hairspring, oscillates around its axis of rotation, dividing the time into equal segments.
Bezel: This is the ring that borders the watch dial. Oftentimes, especially with sport watches, the bezel has the ability to rotate. This is referred to as a bidirectional rotating bezel and can rotate both clock-wise and counter clock-wise. It usually has calibrated markings and can be used to measure elapsed time.
Bridge: This is the only part of the watch movement that is not housed inside the frame. It is fixed to the main frame to support the watch movement.
Calibre: This term usually refers to the make and origin of the movement of the watch.
Case: The case of a watch houses the movement and other parts of the watch. The case can be stainless steel, gold, titanium, or several other metals.
Caseback: This term refers to the back of the case. It can be transparent, allowing the wearer to view the movement of the watch.
Chronograph: A chronograph is a watch with a stopwatch function. Pushers on the side of the case start and stop the second hand on one of the subdials on the face of the watch.
Chronometer: A chronometer watch is a watch that has passed a series of rigorous tests, conducted by Controle Officiel Suisse des Chronometeres (COSC). A watch that is considered a “chronometer” keeps very accurate time.
Complication: This is a function other than timekeeping. Examples include: calendar, chronograph, alarms, date, etc. A watch with additional functions is called a complicated watch.
Crown: This is used for winding and setting the time and date on a watch. The crown can be found on the outside case of the watch. Some watches have “screw-down crowns,” where the crown screws down into the case, increasing the water-tightness of the watch.
Crystal: This is the transparent cover on the front of the watch face. It can be plastic, glass, mineral, or synthetic sapphire. The purpose of the watch crystal is to protect the watch dial.
Deployant Buckle: A deployant buckle is expandable, allowing it to easily be slipped on and off of the wrist. This prevents over wear of the strap and prevents it from over-stretching.
Dial: The front part of the watch that displays the time.
Diving Watch: A diving watch is a watch that is able to withstand long periods of time at deep depths of watch. It also has the ability to tell elapsed time so that the diver knows how long he has been under the water.
Dual Time: This is a watch that displays the time in more than one time zone. The time is either displayed on a separate subdial or with an additional hour hand that tracks time in 24-hour mode.
Escapement: this refers to the device at the center of every watch. It controls the rotation of the wheels and regulates the motion of the hands.The escape wheel, lever, and roller convert the rotary motion of the train to a back and forth motion.
Flyback: A flyback function is available on many chronograph watches. The flyback hand allows one to measure a lap-time, while the regular chronograph hand measures elapsed time. Once a lap-time has been measured, the pusher for the flyback hand is pressed and the hand “flies back” to catch up with the chronograph hand.
Function: Also known as a complication, a function refers to all of the tasks that a watch can perform other than keeping time.
Hairspring: Also called the balance spring, this is the spring that vibrates the balance wheel.
Helium Escape Valve: High-end diving watches will include a helium escape valve. As helium slowly escapes into the watch while it is underwater, it will slowly build up pressure inside of the watch, which can result in blowing off the crystal of the watch. The helium escape valve is a one-way valve that allows the watch to release the helium during decompression.
Horology: The scientific term that refers to the studying of time-keeping and watch making and constructing.
Jewels: Jewels on the inside of a watch help to reduce friction in a mechanical watch, allowing the watch to last longer and keep more accurate time. These jewels are typically made from synthetic sapphires or rubies.
Lugs: The arms on the top and bottom of the case that connect to the watchband.
Luminous: This is a coating on the watch that allows the watch to glow in the dark. Often times, the hour-markers and hands will be coated in the luminous coating.
Mechanical Movement: This refers to a watch that runs without any outside energy source. By winding the mainspring, the watch will run and keep accurate time.
Minute Repeater: A minute repeater is a complicated function that makes a watch very expensive. A watch with a minute repeater makes chimes for the hour, minute, and quarter.
Moonphase: This is a function on the front of a dial that displays the phases of the moon.
Movement: The movement of a watch keeps all of the parts running and moving. Movements can be either mechanical or quartz.
Perpetual Calendar: A watch with a perpetual calendar can automatically adjust for months of different lengths, as well as leap years. They are programmed to be accurate until the year 2100 and can be powered by quartz or mechanical movements.
Pilot’s Watch: A Pilot watch is usually oversized to increase legibility and functionality. A pilot’s watch often features a chronograph and GMT functions.
Power Reserve: A hand on the front dial of the watch points to a number to indicate how many hours of power the watch has left before it will run down.
Quartz Movement: This movement is usually mass-produced, making it less expensive. It is powered by quartz crystals, which are very accurate.
Rotor: A semi-circular piece of metal in the movement of a self-winding watch. It winds the movement’s mainspring by rotating with the motion of the wearer’s arm.
Sub-dial: A small dial on the watch face that can display seconds, power reserve, date, or many other functions.
Tachymeter: This is a common feature found on a chronograph watch. A tachymeter measures an average speed over a measured distance. The scale is usually engraved on the bezel of the watch.
Tourbillon: A tourbillon is found only in high-end luxury watches. A tourbillon has the escapement and balance wheel mounted in a rotating cage in an attempt to eliminate the effects of gravity on the performance of the watch. Because the tourbillon is such a complicated mechanism, a watch with a tourbillon usually has a transparent dial, which allows the tourbillon to be exposed.
Water Resistance: Many watches have the ability to withstand certain levels of water pressure.
Obviously, there are many more terms in the watch world, but these are most of the very important terms. Now that you know what each of these terms mean, you can carry on a conversation with the m
@crownandcaliber on Instagram