Refers to rate constancy of a watch, not only on whether it is showing the exact
time. A watch that gains or looses exactly the same amount every day is considered
Sometimes referred to as Hesolite, an acrylic crystal is composed of a plastic
composite that is generally less expensive and less durable than a sapphire
or mineral crystal. Acrylic crystal flexes rather than shatters on impact, it
produces little glare under bright light, and can be polished easily.
Automatic Watch/Automatic Movement/Automatic Winding
Also called “self-winding,” a watch with automatic movement needs
no battery. The mechanism winds itself by the motion of the watch wearer’s
arm. Most automatic watches have up to 36 hours of power reserve. 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. Typically, an automatic watch is more expensive
than a quartz watch.
A feature that sounds an alarm at a pre-set time or at regular intervals. Alarms
are available on both quartz and mechanical watches.
Commonly found on pilot watches, an altimeter provides altitude by responding
to changes in barometric pressure.
Displays the time with a dial, hands, and numbers or markers.
A watch that displays time in both a digital format and with the hands of a
conventional watch. Usually featured on sport watch styles.
A watch feature that shows the day, date, month and time, adjusting automatically
for short and long months.
Some watch dials have small openings, called apertures, in which certain indications
(such as the date, hour, etc.) are provided.
Unit of pressure used in watch making to indicate water resistance.
Atomic Time Standard
An extremely accurate time that is measured by the U.S. National Institute of
Standards and Technology, Time and Frequency Division in Boulder, Colorado,
through vibrations of atoms in a metal isotope that resembles mercury. Radio
waves transmit this exact time throughout North America and some “atomic”
watches can receive them and correct to the exact time. To synchronize your
watch with atomic standard time, call (303) 499-7111.
Ladies style watch with a thin, elongated face; usually rectangular in shape
but may be oval.
The bracelet or strap that holds a watch on your wrist.
A modern hybrid watch technology that uses a quartz movement powered by a small
electric current generator operated by a rotor. Like an automatic watch, these
must be worn regularly to keep up their electrical power reserve. Also known
under various marketing names, including Kinetic (Seiko), Omega-matic (Omega),
and Auto quartz (Invicta).
The minimum period of time that a battery will continue to provide power to
run a watch. Battery life begins when the factory initially installs the battery.
Battery Reserve Indicator or End of Battery Life
Some watches have a feature—often a movement of the second hand--that
lets you know when the battery is approaching the end of its life.
The ring that surrounds the watch face and holds the crystal in place. A sports
or divers watch could have a rotating bezel to be used as a timer.
Bidirectional Rotating Bezel
A bezel that can be used for mathematical calculations or keeping track of elapsed
time through either a clockwise or counterclockwise movement.
A metal band consisting of assembled links that can be removed to adjust the
fit of a watch. There are also one-piece expansion style bracelets that do not
have a buckle.
A smooth round or oval convex-shaped, polished gemstone. In watch terminology,
it describes a decorative stone set in the watch.
A watch feature that shows the date and sometimes the day of the week and the
Case (or Watchcase)
The metal housing of a watch's parts. Stainless steel is the most common type,
but titanium, gold, silver, and platinum are also used.
The cover for the back of the watchcase that is removed to access the watch
movement for service.
A multifunction sport watch with a stopwatch function. Most have two or three
subdials, or minidials, for measuring minutes and hours.
The chronometer indicates that the watch is in perfect running condition with
high degree of precision according to the Official Swiss Chronometer Testing
The attachment used to connect the two ends of the watch bracelet or strap around
Lets the wearer keep track of the time remaining in a preset period. Particularly
useful for sporting events.
The ridged winding knob on the right side of the case that is used to set the
time (and date). On a manual watch the crown doubles as the winding mechanism
to power the watch.
The clear cover over the watch face or dial. Crystals can be made of mineral,
synthetic sapphire, plastic, or acrylic material. The sapphire crystal is the
Crystal Skeleton Caseback
A Caseback made of transparent material that reveals the intricate movement
of the watch.
Cyclops (Magnified Window)
A small window or lens in the crystal that is added to magnify the date 2 1/2
A watch that indicates the date and day of the week.
The watch face.
A watch that shows the time through changes of digits rather than with hands
on the dial.
Designed and manufactured especially for divers whose lives depend on the reliability
of their watch in the water. Divers watches traditionally feature a graduated,
rotating bezel, screw down winding crown, and must be water resistant to at
least 200m or 660 feet.
A feature found on most quality watches with metal or gold bracelets use to
tighten the bracelet to the wrist. The typical clasp has two pieces of steel
that clip safely beneath one long elegant looking piece of steel. All manufacturers
have slightly different versions and features.
An alarm on a diver's watch that sounds when the wearer exceeds a preset depth.
In most watches it stops sounding when the diver ascends above that depth.
Depth Sensor/Depth Meter
A device on a diver's 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 dial or through a digital display.
A watch that measures current local time as well as at least one other time
zone. The additional time element may come from a twin dial, extra hand, subdial,
or other means.
End of Battery Life Indicator (EOL)
The EOL indicates when it is time to replace the existing battery.
Elapsed Time Rotating Bezel
A graduated rotating bezel used to keep track of periods of time.
Decorative engraving, usually on a watch dial.
The visible side of the watch where the dial is contained, most are printed
with Arabic or Roman numerals.
An additional hand on a chronograph which moves with the second hand but, can
be stopped independently to measure an interval and can then "fly back"
to catch up with the other hand. This is useful for capturing lap times without
losing the ability to capture the finish time.
Foldover Buckle (Deployment)
A three-folding enclosure that secures the two ends of the bracelet. When closed,
the buckle covers the two-piece folding mechanism.
The term used to describe the different tasks each watch component performs.
A rubber or plastic ring that seals the internal works of the watch against
dust, moisture and water.
GMT (Greenwich Mean Time) Timezone
Also known as Zulu Time, as set to the international clock in Greenwich, England,
GMT reflects the world time on a 24-hour scale and is used by pilots worldwide.
Yellow precious metal, which is stainless and very malleable. Used in alloys
to make jewelry, bracelets and watches. The portion of gold in the alloy is
indicated in karats (k).
An application of gold over the surface of an item.
The pointing device anchored at the center and circling around the dial indicating
hours, minutes, seconds and any other special features of the watch.
Hourly Time Signal
Single beep/chime, which rings on the hour, every hour when it is engaged.
Handwinding (Manual Mechanical)
A watch with a manual mechanical movement that must be wound by the wearer using
Bearings that are usually made of synthetic sapphires or rubies in a mechanical
watch. The jewels reduce friction and make the watch more accurate and longer
lasting. These jewels do not add any monetary value to a watch.
Jump Hour Indicator
A jump hour indicator takes the place of an hour hand. It shows the hour by
means of a numeral in a window on the dial of the watch. The minutes and seconds
in a jump hour watch are read as normal from the analog hands and dial.
A small loop on the strap near the buckle. It holds the strap end in place after
the buckle has been fastened.
Based on a revolutionary technology, Seiko Kinetic® watches run entirely
on energy generated from natural movement of the wearer’s wrist. It never
needs a battery.
Liquid-crystal display. Digital time display.
Light emitting diodes. Displays the time in a red light. Found less frequently
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.
A chronograph function that lets the wearer time segments of a race.
Several types of lighted dials are used so that you can tell time in the dark.
A side button activates the light.
The individual attached components that make up metal bracelets.
The metal holdings used to attach the bracelet or strap to the case with pushpins.
Luminous hands and/or hour markers are standard features on most watches that
enable you to tell the time in insufficient light.
Magnified Window (Cyclops)
A small window or lens in the crystal that is added to magnify the date 2 1/2
The watch must be wound by turning the crown back and forth until resistance
is met—usually every 24 hours.
A watch's mechanism that is powered by a manual activity such as being wound
up by hand or by the movement of the watch.
Watch crystal made from what is essentially a form of glass. More scratch resistant
than acrylic, a mineral crystal can scratch and is extremely difficult to polish.
An indicator that keeps track of the phases 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.
Used to seal watch mechanisms to ensure water resistance.
A device that counts the number of strides taken by the wearer.
A type of calendar that automatically adjusts for months of different lengths
and indicates February 29 in each leap year.
One of the rarest precious metals, platinum is also one of the strongest and
heaviest, making it a popular choice for setting gemstone jewelry and watches.
It has a rich, white luster, and an understated look. Platinum is hypoallergenic
and tarnish resistant. Platinum used in jewelry and watches is at least 85 to
95 percent pure. Many platinum watches are produced in limited editions due
to the expense and rarity of the metal.
A measure of the amount of time a watch will run after being fully powered or
wound, with no additional power input.
Power Reserve Indicator
A feature that shows when the watch will soon need a new battery or winding.
A feature on a chronograph watch that measures pulse rate.
Spring action pins that attach the band to the case lugs.
Button located on the case of multifunction watches used to operate the special
A watch with a mechanism powered by a "quartz crystal." The crystal
vibrates when placed in an electronic field, thus powering the watch. Most affordable
watches today have Quartz movements. Quartz watches are mostly battery operated.
Rattrapante (Flyback) Chronograph
A chronograph with an additional hand that moves with the second hand but, can
be stopped independently to measure an interval and can then fly back to catch
up with the other hand. This is useful for capturing lap times without losing
the ability to capture the finish time.
Ratchet Bezel Ring
A bezel ring that can either turn one way (counter-clockwise) or both ways and
generally clicks into place.
Another name for a subdial; this is usually a dial within the main dial of a
A device that chimes the time when the wearer pushes a button.
Used to describe a pointer hand on a watch dial, which returns to zero at the
end of a prescribed period. For example a watch may have retrograde date - in
this case the hand moves up a scale a day at a time, pointing to the current
date - when it reaches 31 it will spring back to 1
Protective coating of metal with a thin layer of rhodium--a hard, brittle metal
which does not oxidize and is malleable only when red hot.
Rose (or Pink) Gold
A softly hued gold that contains the same metals as yellow gold but with a higher
concentration of copper in the alloy.
A bezel that can be turned to perform various functions.
The part that rotates in automatic (self winding) movements and winds the main
Highest quality transparent that is scratch resistant under normal conditions.
Sapphlex Crystal (Seiko Watches)
Highly scratch resistant crystal created by the fusion of sapphire and mineral
Screw-Down Locking Crown
A crown that aids water resistance by sealing to the case of 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 country simultaneously.
This term refers to a mechanically powered watch that is wound by the motion
of the wearer's arm rather than through turning the winding stem.
Specified on a watchcase, it means that a watch can withstand normal wear and
tear, even during strenuous sport activities.
Slide Rule Bezel
A rotating bezel around the outside edge of the watch case that is printed with
a logarithmic scale and assorted other scales and is used in conjunction with
fixed rules of mathematics to perform general mathematical calculations or navigational
A type of quartz movement where the batteries are recharged via solar panels
on the watch face. They have a power reserve so they can run even in the dark.
Solar powered quartz watch. This technology provides the accuracy of quartz,
without the inconvenience and cost of regular battery changes.
A feature on a chronograph that actually is two hands, one a flyback, the other
a regular hand. To time laps or different finishing times, the wearer can stop
the fly backhand independently while the regular hand keeps moving.
An extremely durable metal alloy that is virtually immune to rust, discoloration,
and corrosion; it can be highly polished, thus resembling a precious metal.
Because of its strength, stainless steel is often used even on case backs on
watches made of other metals.
A white and highly reflective precious metal. Sterling refers to silver that
is 92.5 percent pure, which should be stamped on the metal, sometimes accompanied
by the initials of the designer or country of origin as a hallmark. Although
less durable than stainless steel and other precious metals, sterling silver
is often employed in watches that coordinate or look like sterling jewelry.
A protective coating may be added to prevent tarnish.
A watch with a second 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."
A watchband made of leather, plastic, fabric or other non-metal material.
A small dial used for any of several purposes, such as keeping track of elapsed
minutes or hours on a chronograph or indicating the date.
Swiss A.O.S.C. (Certificate of Origin)
A mark identifying a watch that is assembled in Switzerland with components
of Swiss origin, primarily used in Bedat watches.
Common feature in chronograph watches. Measures the speed over a predefined
A rectangular watch with heavier bars on either side of the dial. Inspired by
the tank tracks of World War I and first created by Louis Cartier.
A metal with a texture similar to titanium, but a color similar to gold. Used
by Omega for the gold-like trim on certain titanium watches. Many of these watches
are also available in titanium with real gold trim.
A watch function that finds the distance of an object from the wearer by measuring
how long it takes sound to travel the distance.
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 scratching.
A watch with a barrel-shaped watchcase and two convex sides.
Unidirectional Rotating Bezel/Unidirectional Turning Bezel
An 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
Universal Time Coordinated. A universal time based on the Greenwich Meridian
used by the military and in aviation. Greenwich Mean Time (GMT) can be considered
approximately equivalent to Universal Time Coordinated (UTC). GMT as such is
now obsolete however, being replaced by UTC. Using this timezone/standard avoids
errors and problems associated with different time zones and summer times operational
in different countries.
Watch Winder/Watch Winding Case/Watch Rotor/Watch
A watch winder is a mechanical devise used to maintain the winding on an Automatic
Watch. Automatic watches require constant wearing or they need to be placed
in a watch winder box to maintain the winding and settings of the automatic
watch. A watch winder allows you to own more than one automatic watch and not
have to worry about resetting the time on any of them.
An illegal and misused term: No watch is fully 100 percent waterproof.
Describes the level of protection a watch has from water damage. .A watch bearing
the inscription "water-resistant" on its case back can handle light
moisture, such as a rainstorm or sink splashes, but should not be worn swimming
or diving. If the watch can be submerged in water, it must state at what depth
it maintains water-resistance, i.e. 50 meters (165 feet) or more on most sport
watches. Below 200 meters, the watch may be used for skin diving and even scuba
diving depending upon the indicated depths.
Watches come in different water resistant depths and diver's depths:
Water resistant: Will withstand splashes
of water or rain but should not be worn while swimming or diving.
Water tested to 50 meters (165 feet): Suitable
for showering or swimming in shallow water.
Water tested to 100 meters (330 feet):
Suitable for swimming or snorkeling.
Water tested to 150 meters (500 feet):
Suitable for snorkeling.
Water tested to 200 meters (660 feet):
Suitable for skin diving.
Diver's to 150 meters: Meets ISO Standards
and is suitable for scuba diving.
Diver's to 200 meters: Meets ISO Standards
and is suitable for scuba diving.
Created from yellow gold by incorporating either nickel or palladium to the
alloy to achieve a white color. Most watches made of white gold will be 18k.
Operation consisting of tightening the mainspring of a watch. This can be done
by hand (by the crown) or automatically (by a rotor, which is caused to swing
by the movements of the wearer's arm).
The button on the right side of the watchcase used to wind the mainspring. Also
called a "crown."
World Time Dial
A dial, usually on the outer edge of the watch face, which tells the time in
up to 24 time zones around the world.
A countdown timer that sounds warning signals during the countdown for a boat
The traditionally popular gold. Yellow gold watches may be found in 14k or,
as found from most European manufacturers, 18k.