Watch Glossary

#

12 or 24-Hour Register

The register (often referred to as a recorder) is a sub-dial usually appearing on the front face of a chronograph that can record time periods of up to 12 or 24 hours.

Read

30 Minute Register

Like the 12/24 register, the 30-minute is also a sub-dial on a chronograph that can chart periods of up to 30 minutes at a time.

Read

A

Acrylic Crystal

Acrylic crystal is a type of crystal on the front of your watch (often called the glass or window), that protects the dial and face of the watch.

One thing to take note of is that often inexperienced watch salesmen looking for a quick sale may refer to this type of crystal as a hesolite crystal in an attempt to make it sound more elegant.

However, while acrylic is known for having minimal glare under bright light, it’s a much less expensive crystal than that of mineral or sapphire.

Due to it’s flexibility, it has a tendency to resist shattering when hit or impacted, however it is still much less durable than its more expensive counterparts.

Read

Adjusted

Many people often wonder why their watch says “adjusted” on it or why the salesman opted to use that as a selling feature.

Typically, this refers to the tests the watch undertakes while being assembled.

In order to ensure a quality timepiece with minimal disruption or loss, the watchmaker will calibrate it using at least nine adjustments which include step-up, stem-down, stem-left, stem-right, face-down, face-up, isochronism, heat and cold.

This ensures that when the watch is taken home it can work flawlessly in various environments.

Read

Alarm

Most people understand the purpose of an alarm and that’s simply to alert you of a specific pre-set time.

Typically, this refers to the tests the watch undertakes while being assembled.

An alarm can be on both quartz and mechanical timepieces, where the mechanical ones typically provide an extra hand for setting it.

Inside the movement, there will be a second mainspring that activates a tiny component causing a weight to vibrate back and forth which causes the noise or vibration at the pre-set time.

Read

Altimeter

Typically found in flight or pilot watches, it’s similar to the component found in the cockpit of an airplane.

As one may have guessed, the altimeter’s job is to measure altitude (height above sea-level) which records ascent and descent by responding to changes in barometric pressure.

While this function is important for pilots, it also serves useful for mountain climbers, sky divers or anyone in the need of measuring height.

Read

AM/PM Indicator

Also called a night and day indicator.

The AM/PM function allows the user to determine the time of day on a 12-hour analog or digital watch.

Read

Amplitude

Every time the balance wheel swings back and forth it causes what we refer to as a beat or a tick.

The maximum angle that the balance can swing from its position of rest is the amplitude.

When the balance wheel is in a horizontal position on your wrist the amplitude will typically be between 275 and 315 degrees before spinning around the opposite direction another 275 to 315 degrees.

Poor amplitude will affect the time your watch keeps which is why it’s important to measure the amplitude and properly maintain your watch.

Read

Analog

A term describing a clock or watch having hour and minute hands rather than using digital liquid crystal display (LCD).

Read

Analog/Digital Display

An anidigi or dual display watch displays both an analog and digital time option to the wearer by providing hour and minute hands in addition to a liquid crystal window that shows the arabic numbers.

This type of watch is often utilized by military and emergency service personnel that like the duo display for job related duties such as synchronization, performing CPR or timing with greater ease.

Read

Annual Calendar

The annual calendar is a complication that shows at minimum, the day, date and month, often accompanied by the year.

Some watches contain a perpetual or moon phase calendar as well.

While the watch may account for longer and shorter months, typically it does not take into consideration leap years and therefore must be reset accordingly.

Some calendar watches also require a reset each year between the end of February and beginning to March.

Read

Anti-Magnetic

Along with many other factors, magnetization can cause a disruption in time due to its interference with certain parts of the movement.

Simple household items such as a television, stereo system, car or refrigerator can cause enough magnetism to counteract the balance and prevent accurate timekeeping.

By using alloy parts for certain components such as the escape and balance wheel, the watch can counteract the magnetic field without a change in time.

Most mechanical and automatic watches are now anti-magnetic whereas a quartz watch is not susceptible to magnet fields at all.

Read

Aperture

The aperture is a small window that’s carved or cut into the dial to display various indications such as the day or date.

Arabic Numerals

1, 2, 3, 4, 5, 6, 7, 8, 9, 0

Read

Arbor

The arbor is basically an axle that any moving part of the watch can rotate on.

Think of a merry-go-round with the post in the middle of the gear that turns. That post is the arbor.

Read

Ardillon Buckle

Regular two piece buckle used to attach a leather strap, like the buckle on a belt.

Read

Assembly

The assembly is exactly as it sounds. It’s the manufacturing process of putting all of the parts of a watch together.

One of the reasons I adore luxury and vintage watches is because the assembly was generally done by hand and expertly manufactured by a quality craftsman.

oday, aside from the luxury market, and even sometimes including it, most watches are assembled by machines and then inspected by hand.

Read

ATM (Atmosphere)

A unit of pressure for the standard atmospheric pressure at sea level. One atmosphere is the pressure of 1kg/cm2 and corresponds to 10 meters of depth.

An ATM is displayed as a value such as 5ATM.

Read

Atomic Calendar

The atomic calendar is a complication that takes into account various lengths in months as well as leap years.

Some of these can be pre-programmed thirty or forty years into the future.

Read

Atomic Clock

The atomic clock is the most accurate timekeeping device in the world only losing approximately one second in ever 1,400,000 years

Broadcasted via a radio signal in Boulder, Colorado it’s powered by the US National Institute of Standards and Technology.

Utilizing the vibrations of atoms in a metal isotope similar to mercury, an atomic clock relies on this radio transmission only requiring the user to set the timezone.

Read

Auto Repeat Countdown Timer

An auto-repeat countdown timer automatically resets itself and starts timing again until a stop button is pushed.

Read

Auto Switch Backlight

If activated, a watches’ backlight will automatically illuminate the dial when you turn your wrist toward your face.

Read

Automatic Movement

A mechanical watch movement that is equipped with an oscillating rotor that spins as the wearer’s wrist moves.

The movement of the rotor winds the watch.

Read

Automatic Watch

Invented by Breguet in the 18th century and first worn by John Harwood, an automatic movement is similar to a mechanical watch, but is wound by the daily movements of the wearer’s wrist.

Rather than having to manually wind the stem of the watch, a tiny rotor moves in unison with your wrist which ratchets the mainspring one tick at a time.

A watch that is wound by the everyday movements of the wearer. A tiny rotor turns and swings with whenever the watch is moved. This in turn rotating a tiny gear which ratchets the larger mainspring gear one click at a time.

Often having a reserve, the wearer can go a couple of days without having to reset the watch by winding the stem. However, after about 36 hours, the watch if left unworn will have to be manually wound to restart its process.

Read

Auxiliary Dial

An extra dial for information, also referred to as a subdial, different information is displayed depending on the complication.

Watches can have as many as four auxiliary dials, typically found on chronographs, alarm watches or dual time zones but not restricted to these style watches.

Read

B

Balance Cock

A small bridge that secures the balance wheel with the movement.

Read

Balance Spring

The balance spring, often called a hairspring due to how fine it is, is a very thin spring, no thicker than a strand of hair that coils and recoils causing the balance wheel to swing back and forth regulating the accuracy of time.

Read

Balance Staff

Another word for the Arbor.

Read

Balance Wheel

The heart of the movement that receives the energy to run from the escapement.

The balance wheel beats, or oscillates, in a circular motion between five and ten times per second.

An integral part of any mechanical watch, the balance wheel oscillates to divide and regulate time equally the same as a pendulum does in a clock.

Read

Band

The strap that wraps around your wrist to keep the watch in position..

Typically referring to a leather or rubber band, often called a strap.

Read

Band Width

The band width is the measurement of distance between the lugs of the case.

his is important to note when purchasing a new or replacement band or strap as it determines the size you’ll require in order for it to properly fit your wrist watch.

Read

Bar

Another unit of measurement relating to the pressure a watch can withstand.

One bar is about equal to the atmospheric pressure at sea level and is approximately 10 meters.

Read

Barrel

The barrel is thin drum that encases the mainspring in a mechanical watch and uses a tooth-like rum to drive the train.

What’s important to note is that its size is a direct reflection of how long the power reserve will hold out in a watch.

If a power-reserve is of utmost importance to you, consider trying to find a double barrel which significantly increases the reserve.

Some watches feature a Double-Barrel which allows for extra long power reserve. The toothed rim of the barrel drives the train.

Read

Base Metal

Any non-precious metal.

Read

Battery

A device that converts chemical energy into electricity. Most watch batteries are silver oxide type delivering 1.5 volts.

Much longer lasting lithium batteries are 3 volts.

Read

Battery Reserve Indicator

The end of life function is an indicator that warns you of a soon-to-expire battery in a quartz watch.

This indicator is seen when the wearer notices the second hand jumping in two to four second intervals which will indicate the battery is about to go into failure within approximately two weeks.

Read

Batteryless Quartz Watch

A recent hybrid technology, the watch runs without winding or a battery.

Typically using a small electronic generator, the watch stores energy in its own rechargeable battery device which causes the watch to keep time.

Typically, these watches are known under proprietary brand names and must be worn on a regular basis similar to that of an automatic watch.

Read

Beat

IRefers to the vibration or the tick of a watch; about 1/5 of a second.

The sound is produced by the escape wheel striking the pallets.

Read

Bevel

A filed, turned or obliquely ground surface made to avoid a sharp edge.

Read

Bezel

The surface ring on the watch that surrounds and holds the crystal in place.

A rotating ratchet bezel moves in some sport watches as part of the timing device.

If rotating bezels are bidirectional (able to move clockwise or counter-clockwise) they can assist in calculations for elapsed times or for tracking different time zones.

Read

Bi-Directional Rotating Bezel

This is a bezel that can be rotated both clockwise and counterclockwise.

In order to keep track of elapsed time, you will require this type of bezel.

Read

Bow

The very top of the neck of a pocket watch located above the crown.

This is where the fob or chain is attached.

Read

Box Hinge Case

A box hinge case is a very heavy case with reinforced hinges and heavy metalwork supporting to support the bow/pendant.

Read

Bracelet

Is the metal version of a band or strap used to keep the watch in position on your wrist.

Created using metal links that can be removed for sizing.

Read

Breguet Spring

In 1795 Breguet realized that the spiral hairspring tended to bunch as it coiled and recoiled.

That change in gravity disturbed the balance rate so Breguet raised the last coil of the spring and gave it a smaller curve which greatly improved the rate and also minimized wear on the balance pivots.

Read

Bridge

Metal part in which at least one of the pivots of the moving parts of a watch usually turns.

A bridge is strictly a bar with two supports. A bar is fixed to the bottom plate by steady-pins.

Bars are generally named after the parts they support e.g. barrel-bar, center-wheel bar, etc.

Read

C

Cabochon

Precious stone, polished but uncut.

In French, the word is also used for an embossed ornament on a dial, and of a fancy gilt nail or stud as used by upholsterers.

Typically found set in the crown of a watch.

Read

Cabochon Crown

A winding crow set with a precious or semiprecious stone, usually sapphire, spinnel, or diamond.

Read

Calendar

A complication showing the date and the month.

It often shows the day of the week and the year depending on the complexity of the movement.

Read

Caliber (or Calibre)

Many people often wonder what the is difference between a caliber and movement.

To summarize it, basically the caliber is a part of the movement identifies the position and size of the wheel train and barrel among other components.

When someone asks the type of caliber, typically they’re wanting to know details about the movement, its origins and its manufacturer.

Most calibers are comprised of letters and numbers to identify them.

Read

Cambered Crystal

Cambered crystal means that the window or glass of the watch has been arched creating almost a dome like appearance.

Read

Carat (Karat)

A unit of gold fineness (and gemstone weight).

24K is pure gold, whereas 18K gold is 75% pure.

1.00ct is a 1 carat Diamond.

Read

Case

Container that protects the watch movement from dust, moisture and shocks, often referred to as the body of the watch.

It gives the watch as attractive an appearance as possible, subject to fashion and the taste of the public and is created out of different materials and precious metals.

Read

Case Diameter

The diameter of a case is the measurement from one end of the case to the other not including the crown or buttons.

Read

Case Thickness

The thickness is the measurement from the top of the crystal to the base of the case.

Read

Case

The case of the watch is the metal, or sometimes plastic or ceramic housing that contains all of the various parts of the watch.

Often called the body, it’s the same as the skin of our body which holds everything in place.

Often the case of a watch can greatly increase the value of the timepiece if it’s made using gold, silver, platinum or rhodium.

Read

Caseback

The reverse side of the watch case, laying flat on your wrist.

Some watches feature an exhibition caseback that is transparent allowing you to see the movement.

Casebacks typically carry some engraving noting the name, water resistance and other details.

Read

Chime

A bell like sound made when a clock strikes on the hour, half hour, quarter hour and minutes.

The chime is similar to that found in a grandfather clock.

Read

Chronograph

A chronograph is a watch that does not only indicate the time of the day in hours, minutes and seconds.

It is also equipped with an additional mechanism – operated manually by push buttons –which makes possible to measure continuous or discontinuous intervals of time, from a fraction of a second to 12 hours.

Read

Chronograph Rattrapante

A rattrapante is a fly back hand chronograph that allows the wearer to measure split-seconds or multiple events of varying durations.

Read

Chronometer

A watch that has obtained a certificate from an official neutral testing center after having passed strict precision tests for accuracy.

Two such centers are “COSC” (Controle Officiel Swiss des Chronometres) “SOCC” (Swiss office for chronometric controls)

These tests are performed in a laboratory over a minimum 15-day period.

They test the movement alone, using successive daily rate figures at different temperatures and with the movement in different positions.

Read

Clasp

Refers to a hinged metal buckle that attaches a metal bracelet or leather strap.

Read

Cloisonne

Enamel set between strips of metal and baked onto the dial.

Read

Column Wheel

The upright, notched, rotating wheel in a chronograph that acts as a sliding link to operate the various levers that turn a chronograph on and off and return the chronograph hands to the zero position.

Read

Complication

A complication or complicated watch is simply put, a watch that tells more than just the time.

Simple complications include that of chronographs, alarms and calendars where a more intricate complication, often called a grand complication can include perpetual calendars, tour billions, minute repeaters and more.

Read

COSC:

The COSC is the Controle Officiel Suisse des Chronometre which is the only official chronometer testing organization in Switzerland.

Read

Cosmograph

Invented by Rolex, the cosmograph is similar to the chronograph with one exception.

The tachymeter is located directly on the bezel as opposed to the the outer rim of the dial which gives a more modern look to the timepiece.

Read

Countdown Timer

A feature found predominantly on quartz watches that allows the user to set an allotted time in hours and minutes and have an alarm ring when that time period expires.

Read

Crown

The crown is the knob on the outside of the casing which is used for setting the watch and a variety of its functions.

In addition to setting the watch, the crown is used to wind the mainspring. There are various types of crowns but they all serve the same basic purpose.

Read

Crystal Skeleton Caseback

A skeleton caseback is when the back of the watch has a window made of clear crystal that showcases the craftsmanship and design of the working movement.

Read

Crystal

The crystal is the window into the watch. It’s the clear cover on the watch that protects the dial and it’s parts from dust, debris and other external elements.

Often made of glass, acrylic, mineral or sapphire, each type of crystal has its benefits and drawbacks. Acrylic crystal is an inexpensive plastic that is able to buffed to remove small scratches.

Mineral crystal is more scratch resistant as it’s heat-treated to create a uniquely hard casing.

However, sapphire is the most expensive and durable crystal, Three times stronger than mineral and up to twenty times harder than acrylic, it’s by and far my favorite type of crystal on a watch.

Read

Cuvette

The cuvette is a dust cover that is sometimes present on the case of the watch.

Read

Cyclops

A small magnified lens found on the crystal that is located above the date to make it easier to read.

Read