THE ULTIMATE GLOSSARY OF WATCH TERMS
A watch which alerts you with beeps at pre-set times.
Analog Digital Display: A watch that shows the
time by means of hour and minute hands (analog display)
as well as by numbers (a digital display).
Analog: A watch that shows the time using hour
and minute hands.
Aperture: Small opening. The dials of some watches
have apertures in which certain indications are given
(e.g. the date, the hour, etc.)
Appliqué: Appliqué or applied chapters
are numerals or symbols cut out of a sheet metal and
stuck or riveted to a dial.
Assembling: Process of fitting together the components
of a movement. This was formerly done entirely by hand,
but the operations have now been largely automated.
Nevertheless, the human element is still necessary,
especially for inspection and testing.
Assortiment: French term for the parts used for
making an escapement.
Winding (or Self-winding): This term refers to a
watch with a mechanical movement (as opposed to a quartz
or electrical movement). The watch is wound by the motion
of the wearer's arm rather than through turning the
winding stem. A rotor that turns in response to motion
winds the watch's mainspring. If an automatic watch
is not worn for a day or two, it will wind down and
need to be wound by hand to get it started again.
Balance Staff: Moving part, usually circular,
oscillating about its axis of rotation. The hairspring
coupled to it makes it swing back and forth, dividing
time into exactly equal parts. Each of the movements
of the balance ("tick-tock") is called an "oscillation".
One oscillation is composed of two vibrations.
Bar Lug: In wristwatch-cases, a thin metal rod
fixed between the ends of the watch case for attaching
the wrist bracelet.
Barrel: Thin cylindrical box containing the mainspring
of a watch. The toothed rim of the barrel drives the
Battery Reserve Indicator (or End of Battery Indicator):
Some battery-operated watches have a feature that indicates
when the battery is approaching the end of its life.
This is often indicated by the second hand moving in
two second intervals instead of each second.
The ring that surrounds the watch dial (or face). The
bezel is usually made of gold, gold plate or stainless
Bi-directional Rotating Bezel: A bezel that can
be rotated either clockwise or counterclockwise. These
are used for mathematical calculations such as average
speed or distance or for keeping track of elapsed time
(see "elapsed time rotating bezel).
Bridge: Complementary part fixed to the main
plate to form the frame of a watch movement. The other
parts are mounted inside the frame (part of the "ébauche").
Built-in Illumination: Electro-luminscent lighting
on a watch dial that allows the wearer to read the time
in the dark.
A feature that shows the date, and often the day of
the week. There are several types of calendar watches.
Most calendar watches show the information digitally
through an aperture on the watch face. Some chronograph
watches show the information on sub-dials on the watch
Calibre (caliber): Originally used to mean the
size of a watch movement, this term now denotes a type
of movement (men's calibre, automatic calibre, etc.).
When a calibre number is accompanied by the manufacturer's
mark, it serves as an indication of origin.
Case: Container that protects the watch-movement
from dust, damp and shocks. It also gives the watch
as attractive an appearance as possible, subject to
fashion and the taste of the public.
Casing (up): Process of inserting and fixing
a watch movement into its case.
Chronograph: A watch that includes a built in
stopwatch function - i.e., a timer that can be started
and stopped to time an event. There are many variations
on the chronograph. Some operate with a center second
hand which keeps time on the watch's main dial. Others
use sub-dials to time elapsed hours, minutes and seconds.
Still others show elapsed time on a digital display
on the watch face. Some chronographs can be used as
a lap timer (see "flyback hand" and "split seconds hand").
The accuracy of the stopwatch function will commonly
vary from 1/5th second to 1/100th second depending on
the chronograph. Some chronographs will measure elapsed
time up to 24 hours. Watches that include the chronograph
function are themselves called "chronographs." When
a chronograph is used in conjunction with specialized
scales on the watch face it can perform many different
functions, such as determining speed or distance (see
"tachymeter" and "telemeter"). Do not confuse the term
"chronograph" with "chronometer." The latter refers
to a timepiece, which may or may not have a chronograph
function, that has met certain high standards of accuracy
set by an official watch institute in Switzerland.
Chablon: French term for a watch movement (not
including the dial and hands), of which all or part
of the components are not assembled.
Technically speaking, all watches are chronometers.
But for a Swiss made watch to be called a chronometer,
it must meet certain very high standards set by the
Swiss Official Chronometer Control (C.O.S.C.). If you
have a Swiss watch labeled as a chronometer, you can
be certain that it has a mechanical movement of the
very highest quality.
Countdown Timer: A function that lets the wearer
keep track of how much of a pre-set period of time has
elapsed. Some countdown timers sound a warning signal
a few seconds before the time runs out. These are useful
in events such as yacht races, where the sailor must
maneuver the boat into position before the start of
Crown: A crown is the button on the outside of
the watch case that is used to set the time and date.
In a mechanical watch the crown also winds the mainspring.
In this case it is also called a "winding stem". A screw
in (or screw down) crown is used to make a watch more
water resistant. The crown actually screws into the
case, dramatically increasing the water-tightness of
Crystal: The transparent cover on a watch face
made of glass crystal, synthetic sapphire or plastic.
Better watches often have a sapphire crystal which is
highly resistant to scratching or shattering.
Date: An ordinal number referring to a day of
the month as in the 10th June.
A watch indicating the date, the month and sometimes
the year and the phases of the moon. Also called a calendar-watch
or calendar. A perpetual calendar watch indicates leap
years as well as the date.
Depth Alarm: An alarm on a divers' watch that
sounds when the wearer exceeds a pre-set depth.
Depth Sensor/Depth Meter: A device on a divers'
watch that determines the wearer's depth by measuring
water pressure. It shows the depth either by analog
hands and a scale on the watch face or through a digital
Dial: Indicating "face" or plate of metal or
other material, bearing various markings to show, in
ordinary watches and clocks, the hours, minutes and
seconds. Dials vary very much in shape, decoration,
material, etc. The indications are given by means of
numerals, divisions or symbols of various types.
Watch: A watch that shows the time through digits
rather than through a dial and hands (analog) display.
Direct-drive: Refers to a second hand that moves
forward in little jerks. "Trotteuse" is the
French term for a direct-drive second hand, especially
a center second hand.
Liquid-Crystal Display (LCD). Indication of time or
other data, either by means of hands moving over a dial
(analog display) or by means of numerals appearing in
one or more windows (digital or numerical display).
These numerals may be completed by alphabetical indications
(alphanumerical display) or by signs of any other kind.
Example: 12.05 MO 12.3 = 12 hours, 5 minutes, Monday
12th March. Such displays can be obtained by mechanical
Diving Watch: A watch that is water resistant
to 200 meters, has a one way rotating beze lwith a screw-on
crown and case back along with a metal or rubber strap
(not leather), a sapphire crystal and possibly a wet-suit
Ebauche: French term (but commonly used in English-speaking
countries) for a movement blank, i.e. an incomplete
watch movement which is sold as a set of loose parts,
comprising the main plate, the bridges, the train, the
winding and setting mechanism and the regulator. The
timing system, the escapement and the mainspring, however,
are not parts of the "ébauche".
Time Rotating Bezel: A graduated rotating bezel
used to keep track of elapsed time. The bezel can be
turned so the wearer can align the zero on the bezel
with the watch's seconds or minutes hand. After a period
of time passes, you can calculate the elapsed time from
the position on the bezel. This saves you having to
perform the subtraction that would be necessary if you
used the watch's regular dial.
Escapement: Set of parts (escape wheel, lever,
roller) which converts the rotary motion of the train
into back and forth motion (the balance).
French term for the method of manufacturing watches
and/or movements by assembling their various components.
It generally includes the following operations: receipt,
inspection and stocking of the "ébauche", the regulating
elements and the other parts of the movement and of
the make-up; assembling; springing and timing; fitting
the dial and hands; casing; final inspection before
packing and dispatching.
Factory works: In the Swiss watch industry, the
term manufacture is used of a factory in which watches
are manufactured almost completely, as opposed to an
"atelier de terminage", which is concerned only with
assembling, timing, fitting the hands and casing.
Hand: A seconds hand on a chronograph that can be
used to time laps or to determine finishing times for
several competitors in a race. Start the chronograph,
putting both the flyback hand and the regular chronograph
seconds hand in motion. To record a lap time or finishing
time, stop the flyback hand. After recording the time,
push a button and the hand will "fly back" to catch
up with the constantly moving elapsed-time hand. Repeat
the process to record as many lap times or finishing
times as needed.
Gear Train: The system of gears which transmits
power from the mainspring to the escapement.
Gold plated: A layer of gold electroplated to
a base metal.
Hand: Indicator, usually made of a thin, light
piece of metal, very variable in form, which moves over
a graduated dial or scale. Watches usually have three
hands showing the hours, minutes and seconds.
Bracelet: A watch bracelet that is incorporated
into the design of the case.
Plating: A new method of plating which entails the
combining and electrolysis of certain materials to look
like gold plate, but containing no gold material and
much more durable than gold plating.
Synthetic sapphires or rubies that act as bearings for
gears in a mechanical watch. The jewels reduce friction
to make the watch more accurate and longer lasting.
Kinetic: Refers to the Seiko line of Kinetic
watches. This innovative technology has a quartz movement
that does not use a battery. The movement of your wrist
charges a very efficient capacitor which powers the
quartz movement. Once the capacitor is fully charged,
men's models will store energy for 7-14 days without
being worn and ladies models store energy for 3-7 days.
Of course, if the watch is worn every day the capacitor
is continually recharged. The watch alerts you to a
low capacitor charge when the seconds hand starts to
move in two second intervals.
Lap Timer: A chronograph function that lets the
wearer time segments of a race. At the end of a lap,
he stops the timer, which then returns to zero to begin
timing the next lap.
Lugs: Projections on a watch case to which the
watch band or bracelet is attached.
Plate: Base plate on which all the other parts of
a watch movement are mounted (part of the "ébauche").
Mainspring: The driving spring of a watch or
clock, contained in the barrel.
d'horlogerie: French term for a watch factory which
itself produces the components (particularly the "ébauches")
needed for the manufacture of its products (watches,
alarm and desk clocks, etc.).
Chronometer: Highly accurate mechanical or electronic
timekeeper enclosed in a box also referred to as a box
chronometer, used for determining the longitude on board
ship. Marine chronometers with mechanical movements
are mounted on gimbals so that they remain in the horizontal
position is necessary for their precision.
Measurement Conversion: A feature, usually consisting
of a graduated scale on the watch's bezel, that lets
the wearer translate one type of measurement into another.
As an example; miles into kilometers, or pounds into
Movement: A movement powered by a mainspring, working
in conjunction with a balance wheel. Most watches today
have quartz movements and are powered by a battery.
However, mechanical watches are currently enjoying a
resurgence in popularity.
Movement: Assembly consisting of the principal
elements and mechanisms of a watch or clock: the winding
and setting mechanism, the mainspring, the train, the
escapement, the regulating elements. The inner mechanism
of a watch that keeps time and moves the watch's hands,
calendar, etc. "Anatomically", the movement consists
of the "ébauche", the regulating elements and the other
components. Movements are either mechanical or quartz.
Power Reserve Indicator: A feature that shows
when the watch will soon need a new battery or winding.
A battery reserve indicator on a quartz watch informs
the wearer when the battery is low. Often this is indicated
by the seconds hand moving at two or three-second intervals.
Seiko's Kinetic watches are quartz watches that do not
have a battery (see Kinetic). When a Seiko Kinetic needs
to be wound, the seconds hand will also move in two
Quartz Movement: A movement powered by a quartz
crystal. Quartz crystals are very accurate. They can
be mass produced which makes them less expensive than
most mechanical movements which require a higher degree
Rotating Bezel: A bezel is the ring surrounding
the watch face that can be turned. Different types of
rotating bezels will perform various timekeeping and
mathematical functions (see elapsed time rotating bezel,"
"unidirectional rotating bezel," "bi-directional rotating
bezel" and "slide rule.")
Regulating Elements: Set of parts comprising
the regulating system (sprung balance) and the escapement
(escape wheel, lever and roller).
Repeater: A watch that strikes the hours by means
of a mechanism operated by a push-piece or bolt. There
are various types of repeaters. Quarter-repeater
sounds a low note for the hours and a "ding-dong" for
each of the quarters. A five-minute repeater strikes
the hours, quarters and five-minute periods after the
quarter. A minute-repeater strikes the hours, quarters
and minutes. The "Grande sonnerie" (grand
strike) strikes the hours and quarters automatically
and repeating when a push-piece is pressed down. A chiming
repeater is the type where the quarters are struck on
three or four gongs of different pitch.
Rotor: The part of an automatic (or self-winding)
mechanical watch that winds the movement's mainspring.
A half-disc of heavy metal, which is made to rotate
inside the case of an automatic watch by the energy
produced by the movements of the wearer's arm. Its weight
tends always to bring it back to the vertical position.
Demultiplied by a specially designed device, its rotations
continually wind the mainspring of the watch.
Sapphire Crystal: A crystal made of synthetic
sapphire, a transparent, shatter-resistant, scratch-resistant
Screw-Lock Crown: A crown that can be screwed
into the case to make the watch watertight.
Second: Basic unit of time, corresponding to
one 86,000th part of the mean solar day, i.e. the duration
of rotation, about its own axis, of an ideal Earth describing
a circle round the Sun in one year, at a constant speed
and in the plane of the Equator. After the Second World
War, atomic clocks became so accurate that they could
demonstrate the infinitesimal irregularities (a few
hundredths of a second per year) of the Earth's rotation
about its own axis. It was then decided to redefine
the reference standard; this was done by the 13th General
Conference on Weights and Measures in 1967, in the following
terms: "The second is the duration of 9,192,631,770
periods of the radiation corresponding to the transition
between the two hyperfine levels of the fundamental
state of the atom of caesium 133". Conventionally, the
second is subdivided into tenths, hundredths, thousandths
(milliseconds), millionths (microseconds), thousand-millionths
(nanoseconds) and billionths (picoseconds).
Time-Zone Indicator: An additional dial that can
be set to the time in another time zone. It lets the
wearer keep track of local time and the time in another
Setting (to time): Process of bringing the hands
of a watch or clock to the position corresponding to
the exact time.
Absorber: A resilient bearing which is intended
to take up the shocks received by the balance staff
and thus protects its delicate pivots from damage.
Shock Resistance: As defined by U.S. government
regulation, a watch's ability to withstand an impact
equal to that of being dropped onto a wood floor from
a height of 3 feet.
watch: A watch in which the case and various parts
of the movement are of transparent material, enabling
the main parts of the watch to be seen.
Rule: A device, consisting of logarithmic or other
scales on the outer edge of the watch face, that can
be used to do mathematical calculations. One of the
scales is marked on a rotating bezel, which can be slid
against the stationary scale to make the calculations.
Some watches have slide rules that allow specific calculations,
such as for fuel consumption by an airplane or fuel
Powered: A watch that uses solar energy from any
light source to power the quartz movement. The Citizen
Solar-Tech models use this technology and provide a
180 day power reserve which enables the watch to run
Motor: The part of a quartz movement that moves
the gear train, which in turn moves the watch's hands.
A watch with a seconds hand that measures intervals
of time. When a stopwatch is incorporated into a standard
watch, both the stopwatch function and the timepiece
are referred to as a chronograph.
Striking-Mechanism: In a watch or clock, an automatic
or hand-operated mechanism that strikes the hours, etc.,
or rings an alarm-bell in a repeater watch.
Sub-Dial: A small dial on a watch face used for
any of several purposes, such as keeping track of elapsed
seconds, minutes or hours on a chronograph or indicating
Watch: Only when it is Swiss, may a watch be marked
"Swiss Made" or "Swiss", or any other expression containing
the word "Swiss" or its translation, on the outside.
According to Section 1a OSM, a watch is considered to
be Swiss if its movement is Swiss, its movement is cased
up in Switzerland and the manufacturer carries out the
final inspection in Switzerland.
Also called a "tachometer", it is a feature found on
some chronograph watches. A tachymeter measures the
speed at which the wearer has traveled over a measured
distance. In watchmaking, a timer or chronograph with
a graduated dial on which speed can be read off in kilometers
per hour or some other unit (see timer).
Watch: A rectangular watch designed by Louis Cartier.
The bars along the sides of the watch were inspired
by the tracks of tanks used in World War 1.
A telemeter determines the distance of an object
from the observer by measuring how long it takes sound
to travel that distance. Like a tachymeter (see "tachymeter"),
it consists of a stopwatch, or chronograph, and a special
scale either imprinted on the crystal ring on the inside
of the case but usually on the top outside of the case.
Minute Recorder (or Register): A sub-dial on a chronograph
(see "chronograph") that can time periods of up to 30
Instrument used for registering intervals of time (durations,
brief times), without any indication of the time of
A metal that is used for some watch cases and bracelets.
Titanium is much stronger and lighter than stainless
steel. Titanium is also hypo-allergenic.
Watch: A watch shaped like a barrel, with two convex
Tourbillon: Device invented to eliminate errors
of rate in the vertical positions. It consists of a
mobile carriage or cage carrying all the parts of the
escapement, with the balance in the center of the watch.
The escape pinion turns about the fixed fourth wheel.
The case makes one revolution per minute, thus eliminating
errors of rate in the vertical positions.
Twelve-hour (24-Hour) Recorder (or Register): A
sub-dial on a chronograph (see chronograph) that can
time periods of up to 12 or 24 hours.
Unidirectional Rotating Bezel: An elapsed time
rotating bezel (see "elapsed time rotating bezel"),
often found on divers' watches, that moves only counterclockwise
. It is designed to prevent a diver who accidentally
moved the bezel from its original position to overestimate
his remaining air supply. Because the bezel moves in
only one direction, the diver can still be safe when
timing his dive. Many divers' watches are ratcheted,
so that they lock into place for greater safety.
Movement of a pendulum or other oscillating element,
limited by two consecutive extreme positions. The balance
of a mechanical watch generally makes five or six vibrations
per second (i.e. 18,000 or 21,600 per hour), but that
of a high-frequency watch may make seven, eight or even
ten vibrations per second (i.e. 25,200, 28,800 or 36,
000 per hour).
Material: Loose parts, components either for producing
watches or for repairing them. In the latter case, they
are often called "spare parts" or "repair material".
Resistance: Water-resistant cases have joints that
are made to withstand splashes of water and prevent
water from entering. Terms such as "water resistant
to 50 meters" or "water resistant to 200 meters" indicate
that the watch can be worn underwater to various depths.
An operation consisting of tightening the mainspring
of a watch. This can be done by hand by means of turning
the crown or automatically by means of a rotor, which
is caused to swing by the movements of the wearer's
Stem: The button on the right side of the watch
case used to wind the mainspring. Also called a "crown."
Time Dial: A dial, usually on the outer edge of
the watch face, that tells the time in up to 24 time
zones around the world. The time zones are represented
by the names of cities printed on the bezel or dial.
The wearer reads the hour in a particular time zone
by looking at the scale next to the city that the hour
hand is pointing to. The minutes are read as normal.
Watches with this feature are called "world timers."