In even the most simplistic mechanical watch, one can find an excess of 100 working parts perfectly fit and crafted to fit on your wrist.
While most consumers focus solely on the outside appearance of a timepiece when making a purchase, like a car, a watch should be inspected from the inside out.
The important thing to note with a timepiece is that although the movements may seem overwhelmingly intricate, each part has its purpose and function and no watch can work properly without each of its components. It’s for this reason, that we’re proud to present you with a glossary of parts and points which will hopefully allow you to better understand how your watch works and what to ask for when buying your next timepiece.
Parts, Pieces and Functions:
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.
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.
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.
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.
Most people understand the purpose of an alarm and that’s simply to alert you of a specific pre-set time. 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.
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.
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.
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.
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.
Analog or Analogue Watch:
An analog watch showcases the current time utilizing hour and minute hands rather than a liquid crystal display that digitally forms arabic numbers. As the clock ticks, the hands move clockwise around the dial indicating the time of day. As they progress, they reset after 12-hours and begin again to indicate a difference in AM and PM.
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.
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.
The aperture is a small window that’s carved or cut into the dial to display various indications such as the day or date.
1, 2, 3, 4, 5, 6, 7, 8, 9, 0
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.
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. Today, aside from the luxury market, and even sometimes including it, most watches are assembled by machines and then inspected by hand.
The atmosphere is what indicates the water-resistance of a watch by measuring the normal air pressure at sea level.
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.
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.
Auto Switch Backlight:
If activated, a watches’ backlight will automatically illuminate the dial when you turn your wrist toward your face.
Auto Repeat Countdown Timer
An auto-repeat countdown timer automatically resets itself and starts timing again until a stop button is pushed.
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.
An auxiliary dial is just an extra dial on the face that can be used for a variety of indications depending on the complication.
A small bridge that secures the balance wheel with the movement.
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.
Another word for the Arbor.
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.
A band, is a metal bracelet that snugly wraps around your wrist keeping the watch in position.
The band width is the measurement of distance between the lugs of the case. This 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.
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.
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.
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.
One of the better known watch parts, the bezel is the ring found surrounding the dial of your watch. Often made of precious metals, there are various types of bezels that can be used to measure speed or distance, as well as keeping track of elapsed time.
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.
Box Hinge Case:
A box hinge case is a very heavy case with reinforced hinges and heavy metalwork supporting to support the bow/pendant.
The very top of the neck of a pocket watch located above the crown. This is where the fob or chain is attached.
Similar to the band, the bracelet is a metal strap that secures the watch to the wrist using links that can be removed for sizing.
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.
The bridge of a watch is a metal plate that contains the “jewels” affixed to the main plate which forms the frame of the movement and holds the rotating gears. It’s similar to the pillars that hold up two floors of a building.
Completely decorative with no useful purpose, the cabochon is a smooth round or oval gemstone often found set in the crown of a watch.
The calendar is a complication that shows the date and often the day and year as well.
Cambered crystal means that the window or glass of the watch has been arched creating almost a dome like appearance.
Caliber (or Calibre):
Many people often wonder what the difference between a caliber and movement are. 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.
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.
The diameter of a case is the measurement from one end of the case to the other not including the crown or buttons.
The thickness is the measurement from the top of the crystal to the base of the case.
One of the most popular types of watches, for reasons I often don’t understand, a chronograph is nothing more than w watch with a stopwatch function. Able to accurately measure elapsed and time while showing conventional time it’s driven by the movement and operated by two buttons, one which stops and resets the stopwatch, and the other which starts it. While there are various types of chronographs on the market, most people spend the extra money on the ‘name’ without ever using the feature. For more details, take a look at our Chronograph Guide.
A rattrapante is a fly back hand chronograph that allows the wearer to measure split-seconds or multiple events of varying durations.
The chronometer is a precision timepiece with an expertly-crafted movement that has been rated by the official Swiss testing laboratory called the Controle Officiel Suisse des Chronometeres (COSC). The COSC test measures the performance of the watch at three various temperatures and five different positions for a minimum of fifteen consecutive days. Provided that the mechanical watch is accurate to -4/+6 seconds or quartz watch is accurate to +/-0.2 seconds per day, they will be awarded the coveted COSC chronometer certificate. It’s important to note that very few watchmakers undertake the time or expense of certifying their quartz watches simply because electronic movements are innately accurate and both position and temperature don’t affect them. In fact, to the best of my knowledge, Breitling is the only Swiss watchmaker to consistently certify their quartz timepieces.
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. For a more in depth guide to complications, look here.
The COSC is the Controle Officiel Suisse des Chronometre which is the only official chronometer testing organization in Switzerland.
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.
This feature is exactly what it sounds like. The function allows the wearer to determine how much of a preset time has elapsed.
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.
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.
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.
The cuvette is a dust cover that is sometimes present on the case of the watch.
The cyclops is a small magnified lens in the crystal that is added to enhance the visibility of the date.
An alarm that is activated once per day at a preset time.