Alarm functions may be fitted (most commonly) to battery powered
quartz watches; the alarm with beep at the pre-set time. There are
mechanical alarm watches featuring a hammer which produces the alarm
sound at the pre-set time.
Sometimes used to describe the frequency of a mechanical movement,
however seems more often used to describe the angle of oscillation
of the balance wheel either side of its neutral position. This would
therefore be measured in degrees, for example 'an amplitude of 270
Analogue simply refers to the means of showing the time on a watch
dial by means of hands which point to the hours, minutes and usually
A watch that has both a digital display and hands of a conventional
watch. Usually featured on sport watch styles.
The most commonly-used term in referring to any analog timepiece
that operates on a battery or on solar power and is regulated by a
Aperture: Small opening. The
dials of some watches (in French: montres à guichet) have apertures
in which certain indications are given (e.g. the date, the hour,
Unit of pressure used in watch making to indicate water-resistance.
Auto repeat timer
A feature that allows for continuous operation of a countdown timer.
If timer function is set at one hour and started, it will countdown
to zero, beep with a warning signal and immediately return to the
preset time and start the countdown again. This would continue until
stop button is pushed.
A movement that is all mechanical and requires no winding because
the rotor, part of the automatic mechanism, winds the mainspring
every time you move your hand. When fully wound and left to sit,
most automatics will have up to 36 hours of reserve power.
Mechanical movements are accurate within one minute each day.
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 regulating organ of the watch, vibrating on a spiral hairspring.
Lengthening or shortening the balance-spring makes the balance-wheel
go faster or slower to advance or retard the watch.
A small rod with a sprung pivot at either end to fix the strap
(band) to the case.
Thin cylindrical box containing the mainspring of a watch. The
toothed rim of the barrel drives the train.
Any non-precious metal.
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 volt.
The minimum period of time that a battery will continue to provide
power to run the watch. Life begins at the point of manufacture when
the factory initially installs the battery.
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 bi-directional,
able to move clockwise or counter clockwise, they can assist in
calculations for elapsed times.
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
(see "slide rule") or for keeping track of elapsed time(see "elapsed
time rotating bezel").
Flexible metal band consisting of assembled links, usually in the
same style as the case. detachable links change the length of the
Copper and zinc alloy used to make the main plate and bridge wheels
in the movement.
Usually matching the case, it attaches the two parts of the leather
strap around the wrist.
Push piece controls, usually at 2 o'clock and/or 4 o'clock on the
dial to control special functions such as the chronograph or the
A watch feature that shows the date and sometimes the day of the
week and the month. It can be displayed through a cut-out window in
the dial, as a sud-dial with small hands indicating the day/date
feature or by digital readout.
The dimensions of the watch. Calibre describes the size and
configuration of the movement and can now indicate the shape, origin
and constructor as well.
Unit of gold fineness (and gemstone weight). Pure gold is 24k. 18k
gold is 75% pure.
The metal housing of a watch's parts. Stainless steel is the most
typical metal used but also titanium, gold, silver, and platinum can
be used. Less expensive watches are usually made of brass and plated
with gold or silver.
Chime : The
bell-like sound made when a clock strikes on the hour, half hour,
A multifunction sport watch with a stopwatch function. Most have two
or three sub dials, or minidials, for measuring minutes and hours.
A precision watch that is set in various temperatures and positions,
thus meeting the accuracy standards set by an official watch
institute in Switzerland. Most watch companies either provide this
certificate with a purchase or it can be mailed to you.
The attachment used to connect the two ends of the watch bracelet or
strap around the wrist.
Measures remaining time from preset period of time. (Example: Can be
used to countdown time of a basketball game.)
Button on the outside of the case that is used to set the time and
the calendar, and, in the mechanical watches, to wind the
The clean cover over the watch face. Three types of crystals are
commonly found in watches. Acrylic crystal, a plastic, is
inexpensive and shallow scratches can be buffed out. Mineral crystal
is comprised of several elements that are heat treated to create
unusual hardness that aids in resisting scratches. Sapphire crystal
is the most expensive and durable, approximately three times harder
than mineral crystals and 20 time harder than acrylic crystals. A
nonreflective coating on some sport styles prevents glare.
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 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 a race.
A watch that indicates not only the date but the day of the week.
Depth Alarm :
An alarm on a diver's watch that sounds when the wearer
exceeds a pre-set depth. In most watches it stops sounding when the
diver ascends above that depth.
The watch face. The numerals, indices, or surface design are usually
applied; others have been printed on.
A liquid-crystal display (LCD) enabling a color to appear or vanish
on the surface.
Any watch that shows the time in numbers instead of hands on the
dial. the numbers appear in LCD (liquid crystal diode) which shows a
continuous reading or in LED (light-emitting diode) which shows time
at the push of a button.
A mechanical or solid state watch in which the time shows through
changes of digits, rather than positions of hands on the dial.
Can be displayed by rotating a bezel or digital readout on the face
of the watch. It is used to determine a geographical direction using
the location of the sun.
Indication of time or other data, either by means of hands moving
over a dial (analogue 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 mechanicalor electronic means.
Diving watch: A watch that is water
resistant to 200M. Has a one way rotating bezel and a screw-on crown
and back. Has a metal or rubber strap (not leather). Has a sapphire
crystal and possibly, a wet-suit extension.
Dual Time :
A watch that simultaneously display current local time as well as
one other time zone. The additional time element may come from a
twin dial, extra hand, subdials, or other means
elapsed time rotating bezel: A graduated
rotating bezel (see "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 read the elapsed time off the bezel. This
saves you having to perform the subtraction that would be necessary
if you used the watch's regular dial.
escapement: Device in a mechanical movement that controls the
rotation of the wheels and thus the motion of the hands. Set of
parts (escape wheel, lever, roller) which converts the rotary motion
of the train into to-and-fro motion (the balance).
The visible side of the watch where the dial is contained, most are
printed with Arabic or Roman numerals. Note: traditionally IIII,
rather than IV, is used to indicate the 4 o'clock position.
A seconds hand on a chronograph that is used to determine lap or
finishing times for several competitors. To operate, put both the
flyback and the regular second hand in motion, then to record a lap
or finishing time, the flyback hand can be stopped. After taking the
results, push a button and the flyback hand will catch up to the
constantly moving second hand.
The number of vibrations a second, in hertz (Hz).
: Most water resistant watches are equipped with gaskets to
seal the case back, crystal, and crown to protect against water
infiltration during normal wear. It is important to have the gaskets
checked every two years to maintain the water resistance of the
Gear Train : The system of
gears which transmits power from the mainspring to the escapement.
glass (Crystal): Thin plate of glass or transparent synthetic
material, for protecting the dials of watches, clocks, etc.
plating : A layer of gold that has been electro-deposited
onto a metal; its thickness is measured in microns.
Grande Sonnerie : A type of
repeater that sounds the hours and quarter hours when the wearer
pushes the button
: The pointing device anchored at the center and circling
around the dial indicating hours, minutes, seconds and any other
special features of the watch. Watches usually have three hands
showing the hours, minutes and seconds.
Hourly time signal
Single beep/chime which rings on the hour, every hour when it is
: An hour indicator on an analog watch dial, used instead of
Synthetic sapphires or rubies that act as bearings for gears of a
mechanical watch. A quality hand wound or automatic mechanical watch
contains at least 17 jewels. 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. Movement of your wrist charges a very
efficient capacitor which powers the quartz movement. Once the
capacitor is fully charged, mens models will store energy for 7-14
days without being worn. 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 Memory :
The ability, in some quartz sport watches, to preserve in the
watch's memory the times of laps in a race that have been determined
by the lap timer. The wearer can recall these times on a digital
display by pushing a button.
Lap Timer : A chronograph
function that lets the wearer time segments of a race. At the end of
a lap, he/she stops the timer, which then returns to zero to begin
timing the next lap.
Limited Editions : A watch
style manufactured in a specific amount, often numbered, and
available in limited quantities. Limited editions are available from
most fine watch manufacturers and may be highly prized by
Liquid-Crystal Display : (LCD)
A digital watch display that shows the time electronically by means
of the liquid held in a thin layer between two transparent plates.
environmentally safe illumination technology that will glow brightly
for hours without pushing a button or drawing energy from a battery.
self illuminating paint used on hands and markers.
A hand-wound mechanical watch.
Highly accurate mechanical or electronic timekeeper enclosed in a
box (hence the term 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.
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.
Unit of measurement of the thickness of the gold coating. 1 micron =
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
Watch glass that has been tempered to increase its scratch
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.
A device that counts the number of strides taken by the wearer by
responding to the impact of the wearer's steps.
Power Reserve : The time the
watch will run with a fully charged power supply. For mechanical
watches it is usually 44 hours. For quartz watches it can vary from
18 moths to 10 years.
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 second intervals.
Pulsimeter : A scale on a
chronograph watch for measuring the pulse rate.
Quartz crystal movement
A movement which allows a watch to be worn without being wound. This
technology employs the vibrations of a tiny crystal to maintain
accuracy of time. A digital quartz has no mechanical parts but is
powered by a battery.
Rotating Bezel :
A bezel (the ring surrounding the watch face) that can be turned.
Different types of rotating bezels perform different timekeeping and
Transparent sapphire is used for scratch-proof watch glasses.
Screw-Lock Crown :
A crown that can be screwed into the case to make the watch
Second 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
Shock Absorber : Resilient
bearing which, in a watch, is intended to take up the shocks
received by the balance staff and thus protects its delicate pivots
Shock Resistance : As defined
by the US government regulation, a watch's ability to withstand an
impact equal to that of being dropped onto wood floor from a height
of 3 feet.
Skeleton Case : A case with a
transparent front or back that allows the wearer to view the watch's
Skeleton Hands : Cutout hands
showing only the frame.
Slide 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 weight.
Solar Powered Batteries :
Batteries in a quartz watch that are recharged via solar panels on
the watch face.
Measures the elapsed time of a certain moment of an event.
If you want to know the elapsed time at a certain point during a
track meet, you can tell exact time by using this.
The chronograph keeps running while split time is being displayed.
Therefore, when split time is released the display returns to
original measurement of total elapsed time.
Stainless Steel : An extremely
durable metal alloy (chromium is a main ingredient) that is
virtually immune to rust, discoloration and corrosion; it can be
highly polished, thus representing a precious metal. Due to this and
the importance of white metal jewelry, steel has become a popular
setting for diamonds. Because of its strength, stainless steel is
often used even on casebacks of watches made of other metals.
Timekeeping instrument which can be used for measuring
intervals of time. When this is done, the time display is partly or
wholly lost until the hands are reset.
A watch band made of leather, plastic or fabric.
Subdial : A
small dial on the watch face used for any of several purposes, such
as keeping track of elapsed minutes or hours on the chronograph or
indicating the date.
Sweep Seconds-Hand : A seconds-hand that is mounted in
the center of the watch dial.
Tachymeter (also tachometer)
A watch function that measures the speed at which the wearer
traveled by means of a numeric scale on the watch bezel of a
chronograph. Frequently used to determine a speed of a car over a
A watch function that finds the distance of an object from the
wearer by measuring how long it takes sound to travel that distance.
Like a tachymeter, a telemeter consists of a stopwatch function and
a special scale on the dial of a chronograph.
Instrument used for registering intervals of time (durations,
brief times), without any indication of the time of day.
The "space age" metal, often with a silvery-gray appearance. Because
it is 30 percent stronger and nearly 50 percent lighter than steel
it has been increasingly used in watch making, especially sport
watch styles. Its resistance to salt water corrosion makes it
particularly useful in diver's watches. Since it can be scratched
fairly easily, some manufacturers use a patented-coating to resist
Two Tone :
A watch that combines two metals, usually yellow gold and stainless
steel in the case of fine watches.
unidirectional rotating bezel: An elapsed time rotating bezel
(see "elapsed time rotating bezel"), often found on divers' watches,
that moves only in a counterclockwise direction. It is designed to
prevent a diver who has unwittingly knocked the bezel off its
original position from overestimating his remaining air supply.
Because the bezel moves in only one direction, the diver can err
only on the side of safety when timing his dive. Many divers'
watches are ratcheted, so that they lock into place for greater
Water-resistance is usually measured in atmospheres (ATM), which is
equal to 10 meters of water pressure. (Some European-made watches
use the term "bar" instead). Watches come in different depths of
water resistant as below :
resistant— Wearable while water is being splashed but not under any
Water Resistant —Wearable around sink, during swimming, athletic
sport, in shallow water but not while snorkeling or scuba diving.
100M Water Resistant —Wearable around sink, during swimming,
poolside diving, snorkeling.
Water Resistant — Wearable around sink, during swimming, snorkeling,
jet-skiing, but not scuba diving
Operation consisting in tightening the mainspring of a watch. This
can be done by hand (by means of the crown) or automatically (by
means of a rotor, which is caused to swing by the movements of the