Glossary of Watch Terminology
Finding the watch you would
like can be difficult when you encounter the number of terms that are used
to describe watch functions and parts. To help you we've come up with a
list of some of the most used terms. This list is not exhaustive though so
if there are others you think should be included please let us know.
This is a watch that you can tell the time using hour and minute
Analog - Digital
This is a watch that has both hands and a digital display in numbers.
Where the date is displayed within the dial of the watch
A measure of the water resistance of a watch.
An automatic watch has a mechanical movement and does not need to be
regularly wound. Its power comes from the movement of your wrist as you
wear it. Most automatic watches have a power reserve of up to 36 hours.
Battery Reserve Indicator
Some Quartz watches have this function. The watch will indicate when the
battery is nearing the end of its life. This can often be seen by
observing the movement of the hands which will jump 2-4 seconds depending
upon the make and model.
The Bezel is the ring around the dial of the watch. Often it serves as
other functions (as is the case with a Bi-directional Rotating Bezel).
It is often made of Stainless Steel or Gold (or Gold Plated).
Linked metal strap on a watch. You can change the length by removing
Stainless Steel with a Matt 'brushed' effect finish.
The buckle joins the strap together and is often made of the same
material as the case of the watch.
The size and configuration of the movement inside the watch.
The metal outside of the watch which holds the mechanism.
A watch with 3 subdials within the larger dial. Used to display other
functions of the watch such as a stopwatch.
A Standard set by the Official Watch Institute of Switzerland (COSC).
The watch would have been rigorously tested for its accuracy at various
temperatures and in different atmospheres and is supplied with a
The clasp attaches the strap or bracelet at either end.
As with a Chronograph, except that the Tachymeter function is found on the
bezel of the watch.
The crown is the button on the side of the watch (usually the right)
which changes the time and date of the watch. The Crown is also used to
wind the watch depending on its movement.
The glass on a watch can be made of Plexi Glass (A synthetic Crystal)
or Sapphire Crystal depending upon its make and age.
Dual Time Zone
A watch that can display at least 2 time zones by means of a Subdial, an
extra hand etc.
The clasp folds under the strap of the watch.
Suitable to wear over a diving suit
End of Life (EOL)
Indicates the end of life of a battery within a quartz watch by
succesive jumps of the seconds hand of 4 seconds or a flashing digital
The number of vibrations a second, in hertz (Hz).
A seconds hand on a chronograph that is used to determine lap or finishing
Greenwich Mean Time, used as universal standard time.
Gold is a metal that is used as an alloy frequently in watch making.
The amount of gold is measured in Carats.
A type of Dial. As opposed to a flat colour, a Guilloche dial is
textured with engravings.
The pointing device anchored at the center and circling around the dial
indicating hours, minutes, seconds and any other special features of the
Helium Escape Valve
Decompression System allowing helium to escape from inside the watch. Used
professionally in decompression chambers.
The art and study of watch making.
Within a mechanical watch the jewels are used as bearings. Most watches
with mechanical movements will contain at least 17 jewels.
Based on a new technology, Seiko Kinetic watches run entirely on generated
energy from natural movement of your wrist. It does not require a battery.
Liquid-crystal display. This digital time display is used by longines to
give additional chronograph indications.
On the case, this is where the bracelet or strap is joined.
Illuminating paint on the batons, numerals and/or hands of certain
A hand-wound mechanical watch.
Describes a movement with a balance wheel.
A movement based on a mainspring which is wound by hand; when wound, it
slowly unwinds the spring in an even motion. An automatic mechanical
requires no winding because of the rotor, which winds the mainspring every
time you move your body.
Military or 24-hour time
When time is measured in 24-hour segments. To convert 12-hour time into
24-hour time, simply add 12 to any p.m. time. To convert 24-hour time into
12-hour time, subtract 12 from any time from 13 to 24.
Watch glass that has been tempered to increase its scratch resistance.
A complication on a watch that can strike the time in hours, quarters, or
seconds by means of a push piece.
An indicator that keeps track of the phases of the moon. A regular
rotation of the moon is once around the earth every 29 days, 12 hours, and
44 minutes. once set, the moon phase indicator accurately displays the
phase of the moon.
Iridescent, milky interior shell of the fresh water mollusk that is sliced
thin and used on watch dials. While most have a milky white luster,
mother-of-pearl also comes in other colors such as silvery gray, gray
blue, pink, and salmon.
The inner workings or assembly that make up the main timekeeping
mechanism. movements are either quartz or mechanical. This is the engine
of the watch.
Invented in 1926 by Rolex. At the time it was described as" the first
waterproof, airtight and dustproof watch. Named Oyster due to its shape.
A perpetual rotor converts the movement of the wrist into energy that can
be stored and powers the watch.
Pink Gold (Also Rose Gold)
Gold Metal with a pink/rose tint
Shiny Stainless Steel used in many fashion pieces. (As opposed to
A Watch which is powered by a battery
Stainless Steel and 18ct Gold Case and Bracelet on a Rolex.
A bezel that can be turned. Different types of rotating bezels perform
A transparent crystal frequently used in watch making due to its
resistance to scratching.
Screw-Locking Crown (Also Screw-in Crown)
The screw-in crown seals the crown against the case and aids water
Solid End Links (SEL)
On some recent Rolex watches they have solid links on the bracelet.
A Metal alloy which is known for its resistance to rusting. The most
common metal used in watch making.
A band to secure the watch to your wrist. Can be leather, rubber, canvas
A smaller dial within the face on a Chronograph to display other
functions, such as the date.
A wheel visible on the dial of a watch displaying the sun and moon
over a 24 hour period.
Often used in the motor industry to measure the speed of a car over a
specific distance. Functions via a scale on the bezel of a chronograph.
Average speeds or hourly production rates can be calculated over a period
of observation of less than 60 seconds
A stronger and lighter metal than Stainless Steel and increasingly
used to make watches.
Beware if a watch is described as waterproof as this would not be the
case. No watch is considered 100% Water Proof and watches are not allowed
to be termed as such. See Water Resistant for correct terminology)
A watch classed as this is able to withstand splashes of water (Eg. In
the kitchen or in the rain) but cannot be used for swimming or diving.
Diving watches are classified as "Water resistant to 200 meters" to
indicate the depth to which it can withstand pressure. For more details
see individual model descriptions
An 18k alloy of yellow gold with nickel or similar metal
Either 14k or 18k. The traditional gold used in watch making in both
all gold or bi-metal combinations.