Watch Glossary

Here are several vocabulary terms that are commonly used in the world of watches. I hope it is helpful.

analog

Time is displayed on a dial with the use of hands to indicate the time.

anodized

A very hard, ceramic coating on aluminum created by an electrolyticprocess. Various colors may be produced using this coating process.

anti-magnetic

A watch that is resistant to magnetism. A term used to describe theuse of non-magnetic materials used in the parts of a watch most affectedby magnetization (balance wheel, balance spring and escapement).

antiquarianhorologist

A person who practices the art and science of horology,with specific or specialized interest in the study of antiquetimepieces.

aperture

Small open windows on the dial of a watch used for displaying certainindications, such as day, date, month, hours, minutes, etc.

Arabic numerals

A style of numerals commonly used on watch dials (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12).

arbor

An axis or shaft supporting a moving part such as a wheel or lever.

ATM(atmosphere)

The waterproof pressure ratings of a watch. A watchrated to One Atmosphere would be waterproof to 10 Meters or 30 Feet.

atmosphere(ATM)

The waterproof pressure ratings of a watch. A watch rated toOne Atmosphere would be waterproof to 10 Meters or 30 Feet.

automaticmechanical wind

A watch which has mechanical moving parts and windsits mainspring automatically using an internal rotor system.

automaticwinding

The watch mainspring is wound automatically by a deviceinside the movement which rotates due to normal wrist motion whilewearing the watch.

baguette

A diamond or gem cut in the shape of a narrow rectangle.

balance

A series of internal parts known as the balance assembly. Oscillatingback and forth governs or controls the watch escapement of power,dividing each swing or oscillation of the balance into two equal partsof time.

balance cock

An internal bridge that supports the balance assembly in position.

balancespring

An internal part of a watch which controls the balance wheeloscillations. Due to its size, it is sometimes referred to as ahairspring.

balance staff

The axle or shaft of the balance wheel.

balancewheel

A component of the balance assembly comprised of the balancewheel, hairspring, balance weights, rollers, roller jewels and staff.This assembly controls or governs the escapement and oscillation or timerate of the movement.

barrel

A cylindrical drum-shaped machine part holding the mainspring that powers the watch.

beat

The sound of a watch ticking, usually about 1/5 of a second. The escape wheel striking the pallets produces the sound.

bezel

A frame or ring which holds the crystal of a watch.

bracelet

A type of metal attachment designed for securing a watch to the wrist.

Braillewatch

A watch designed especially for sight-impaired individuals.There is no crystal over the dial. It is fitted with protrusions inplace of normal numerals so the characters and hands may be touched byhand.

bridge

An internal part of the watch movement that has two supports. Thesehelp make up the frame of the movement that holds parts together.

bubbleback

A slang term given to the first style of automatic winding watchmade by the Rolex Watch Co. due to its larger than normal bowed out or bubble style case back.

buttons

External pieces mounted on the outside edge of a watch case used toactivate various functions of a watch, such as the chronograph and alarmfeatures.

cabochon

A gem that is highly polished, yet uncut.

calibre

The physical size design or layout style of the internal movement ofthe watch. Many watch companies have numbered these designs foridentification purposes.

carillon

A style of repeater watch that strikes on three chime rods (instead of two) which are tuned to octaves.

case

The primary housing for the internal watch movement.

chronograph

A watch with a complicated feature allowing measurement of fractionsof a second and elapsed time, independent of the watch displaying normaltime.

chronometer

A watch which has been measured for accuracy and tested for precision by an official testing institute.

chronometerescapement

A high-grade escapement invented in the late 1700s for usein larger style mechanisms (marine or box chronometers) on ships todetermine longitude. The most famous type of chronometer escapement is the detent style.

CivilDay

The accepted ordinary way of keeping time in most parts of theworld. The day is divided into two parts, each from 1-12 hours. One partfor day, and one part for night. Also known as the Mean Solar Day.

coin watch

A watch in which a coin is used as the case.

complication

A term used to describe an added feature to a watch, making it morethan a simple timepiece. Examples: chronograph, split-chronograph, day,date, month, repeater, etc.

CoordinatedUniversal Time (U.T.C.)

The official measurement of time throughoutthe world, completely independent of all time zones.

crown

A knob on the outside of the watch case used for winding the mainspring, setting the time and calendar functions.

crystal

The transparent part over the dial used to protect the dial and handsof the watch. Pocket watch crystals were originally made of glass.Wrist watch crystals are normally made of synthetic materials, such assynthetic mineral crystal or acrylic.

cyclops

A slang term for the small lens on the crystal used to magnify the date.

damaskeen(damascene)

Ornamental engraving on the plates and bridges of awatch. This includes etched designs and geometric patterns.

date

Displayed on a watch dial, the numbers 1-31 represent the days of acalendar month, or the named day of the week and the number of thecalendar month. Watches that display perpetual calendar functions willalso display the named calendar month and sometimes the leap year cycle(1-4).

demi-huntercase

A style of watch case that has a closed lid or cover over thedial, but a small opening in the center of the lid to read the timewithout having to open the lid to view the complete dial.

deployantclasp

A hinged fold-over style metal clasp that opens and closeseasily, allowing the watch to be placed on the wrist or removed withoutthe use of a traditional buckle.

detent

An internal movement part which locks on part of a mechanism. In thesetting mechanism of a watch, a detent could lock into the settingposition, winding position and possibly a quickset date position.

dial

The part of a timepiece which allows you to read the time or observeother functions the timepiece may perform. Also known as the face.

digital watch

A watch that displays time directly using Arabic numerals instead of the use of a dial and hands.

displayback

The case style of a pocket or wrist watch with a crystal mountedas the case back so the movement may be easily viewed.

double-quick

A setting position from the watch winding stem assembly allowing aperson to change the day and date without having to advance the handsthrough a 24 hour period.

dual-time

A watch that displays the time from two separate time zones.Normally, these watches are made with two separate movements.

ebauche

A commercial term in the watchmaking industry for an unfinishedmovement. Some companies specialize in the manufacture of rough finishedmovements, while other companies specialize in the finishing andassembly of these movements.

electricwatch

A timepiece which uses the energy from a battery to runelectro-mechanical components as well as wheels, gears and pinions thatare common to traditional mechanical watches. Electric watches useanalog display and were first marketed in 1957 by the Hamilton WatchCompany, USA.

electronicwatch

A battery powered watch which uses electrical energy to cause asynthetic quarter crystal to vibrate at the very high rate of 100kilocycles per second. Electronic quartz watches are some of the mostaccurate watches produced.

Elinvar

Derived from the words elasticity and invariable, this hairspringis composed of a special alloy which does not vary (expand or contract)with temperature change.

Ephemerous Time

The time calculated for the Earth to orbit once around the Sun.

equationof time

The difference between solar time as displayed on a sun dialand Mean Time. With the use of an Equation of Time table, it is possibleto calculate Mean Time with the results of a sun dial and conversiontables.

escape wheel

Escaping one pulse at a time, it is the last wheel in a train, and works with the fork or lever.

escapement

A series of internal parts which allow the release of mainspringpower through the rotary motion of the watch train of wheels into theback and forth motion of the balance assembly oscillation into equaltime intervals.

expositionback

A case style of a pocket or wrist watch where the crystal ismounted as the case back so the movement may be viewed easily.

five-minute repeater

A complicated watch that strikes (chimes) the hours and five-minute intervals.

fly-backhand

A feature of a watch which allows you to measure fractions of asecond and elapsed time by two separate recording hands, independentlyof the watch displaying normal time.

fob

A small, decorative object that is attached to a pocket watch chainand worn outside the pocket or vest for viewing. Objects such as lodgeand commercial company logos were very popular, as well as miniatureobjects like trains and horses.

GMT

Greenwich Mean Time is the standard for timekeeping and wasintroduced in England in 1880. It is the Mean Time of a Solar Day.

gold-filled

A thin sheet of gold (normally at least 20 microns thick) which is bonded to one or both sides of a base metal.

gold-plated

A coating of a gold alloy over a base metal by eitherelectro-depositing and/or a chemical process. Recommended minimumthickness should be 10 microns thick.

GreenwichMean Time

Greenwich Mean Time (GMT) is the standard for timekeepingintroduced in England in 1880. It is the mean time of a solar day.

guilloche

A pattern or style of pattern on a case or dial known as "engine-turned."

hackmovement

A style of movement normally fitted with a sweep centerseconds hand, where the balance assembly is stopped when the watch isplaced in the setting position. This allows the time to be set moreaccurately.

hairspring

An internal part of a watch which helps control the balance wheel'soscillations. Sometimes referred to as the balance spring.

half-quarter hour repeater

A complicated watch that strikes (chimes) the hours and nearest half-quarter hour.

hand

An indicator mounted over a dial or scale to indicate the time orother functions of a watch. It is normally made of metal in many stylesand designs.

horologist

A person who practices the art and science of horology.

horology

The scientific and artistic study of the working of mechanismsdesigned to indicate the time of day and the measurement of the passageof time.

huntingcase

A style of case that has a closed lid or cover over the dialwhich can be opened and closed by a spring-release button. Both pocketand wrist watches use this style of case design.

Incabloc

A type of shock-resisting system where the jewels have springs tohold them in place. This allows the balance to have some 'give' if thewatch receives a shock.

jewel

The internal part of a watch used to reduce friction, such as abearing. Normally made of synthetic material. However, some high gradewatches use both precious and semi-precious stones.

jumpinghour

A watch with apertures on a solid case front with small dialsbehind the apertures displaying one hour indications at a time.Normally, minutes are displayed in a semi-circular aperture whichdisplays more than one minute indications on a circular dial.

karat

Standard by which the fineness or purity of gold is defined. 24 karatfine is pure gold (1000/1000 parts). 18 karat is 75% pure gold(750/1000 parts). 14 karat is 56% pure gold (560/1000 parts).

karruesel

Self-compensating device designed to overcome various verticalposition timing errors. The entire escapement and balance assembly ismounted on a carriage and revolves like a tourbillon, only more slowly.

key-set

Method of setting the hands of a keywind/keyset pocket watch by usinga small key. The key is placed on the setting arbor and turned to setthe hands.

key-wind

Refers to winding an antique watch with the use of a key and winding arbor on the movement.

L.E.D.

(Liquid Electronic Display). A semi-conductor diode which transformsapplied voltage and converts it into light. LED is used in digitaldisplays on electronic quartz watches.

LeapYear

One extra day (February 29) is added to the calendar every fouryears to compensate for the quarter-day difference in an ordinary year(Mean Solar Year) and the astronomical year (Sidereal Year).

leverset

Method of setting the hands on a pocket watch by using a leverlocated under the bezel. The lever is pulled to the "out" position, thenthe winding crown is turned to set the hands.

LiquidElectronic Display

(LED) A semi-conductor diode which transformsapplied voltage and converts it into light. LED is used in digitaldisplays on electronic quartz watches.

lugs

Two pairs of case extensions at opposite ends of the case which allowattachment of the band or bracelet to the watch case.

mainspring

The principal or power spring of a watch.

mainspring barrel

A geared barrel that houses the watch mainspring.

marinechronometer

A high-grade, larger mechanism invented in the late 1700sfor use on ships to determine their longitude. Mechanical chronometersare placed in wooden boxes and mounted on gimbals so they willconstantly remain in the horizontal position for greater accuracy.

Mean Solar Day

The average of all of the solar days in one year.

mechanicalautomatic wind

A watch which has mechanical moving parts and windsits mainspring automatically using an internal rotor system.

mechanical manual wind

A watch which has mechanical moving parts and requires its mainspring to be manually wound.

minute repeater

A complicated watch that strikes (chimes) the hours, quarter hours and minutes past the previous quarter-hour.

moonphase

The function or complication of a watch which displays the phases of the earth's moon cycle.

movement

The internal mechanism of a watch. Assembly of parts and maincomponents such as the mainspring, balance assembly, escapement, trainof wheels, setting and winding .

musicalwatch

A watch made with a mechanism like a music box that plays amelody on each hour automatically, or on demand with a slide or button.

offsetseconds

A style of dial where the sub-seconds of a watch is locatedto one side of the conventional 6:00 location of a sub-seconds dial.

open face

A style of case where the dial is open to view and is not covered by a lid or cover, as in a hunting style case.

Oyster Perpetual

A term given by Rolex to the movement of it's self-winding waterproof watches

Oyster watch

The name given by Rolex Watch Company to their waterproof watches.

pallet

Shaped like a ship's anchor, this is part of the lever escapement.

patina

Discoloration or oxidation of any surface due to age.

pave

A style of setting stones so close together that no metal is allowed to show.

pendant

The part of a pocket watch where the bow and winding crown are attached.

pendant set

Method of setting the hands on a pocket watch by using the stem and winding crown.

perpetualcalendar

A function or complication of a watch which displayscorrectly, without adjustment, the day, date and month, and alsoaccounts for leap year cycles.

pivot

The end of an arbor which has been reduced or turned down. Threecommon styles of pivots are conical, cone and square shoulder.

plate

This part of the movement supports the other plates and bridges.

platinum

A hard, white metallic element used in the manufacture of watch cases and bracelets.

pocket chronometer

A pocket watch fitted with a chronometer-type escapement.

pocket watch

A watch designed to be worn in a pocket.

power reserve indicator

An indicator hand on a dial which displays how much the mainspring is wound up or down.

pulsimeter

Type of chronograph with a dial scale indicating the average heartbeat rate over a certain period of time.

pushbutton

External button on outside edge of case. Used to start or stopspecific functions or complications of the watch, such as chronographsand alarms.

pushers

External pieces mounted on the outside edge of a case used toactivate various functions of a watch, such as the chronograph and alarmfeatures.

quarter-hour repeater

A complicated watch that strikes (chimes) the hours and quarter-hours.

quartzwatch

A watch whose battery-powered mechanism uses electrical energyto cause vibrations in a synthetic quartz crystal at the very high rateof 100 kilocycles per second. Electronic quartz watches are some of themost accurate watches produced.

quick-date

A setting position from the watch winding stem assembly allowing aperson to change the date without having to advance the hands through a24 hour period.

quick-set

A setting position from the watch winding stem assembly allowing aperson to change the day or date without having to advance the handsthrough a 24 hour period.

regulator

Part of the watch movement used to speed up or slow down the beats, bringing the watch to more exact timing.

repeater

A function or complication of a watch which strikes (chimes) thehours by an internal mechanism operated by an external lever or button.Various types of repeater designs have been made. A minute repeaterstrikes the hours, quarter hour and minutes past the previous quarterhour. A quarter-hour repeater strikes the hours and quarter hour. Ahalf-quarter-hour repeater strikes the hours and nearest half quarterhours. A five-minute repeater strikes the hours and five minuteintervals past the hour.

reverso

A style of rectangular wrist watch case that can be turned over orreversed within the main frame of the case. One side shows the view ofthe normal dial, and one side either has the back of the case or anotherdial type, such as one for displaying dual-time.

rhodium

A hard, white, metallic element that is of the platinum elementgroup. Often used to alloy with platinum. Often used in the manufactureof watch cases and bracelets.

rolledgold plate

A thin sheet of gold (normally at least 20 microns thick)which is bonded to one or both sides of a base metal.

Roman numerals

Style of numerals commonly used on watch dials (I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII).

rotatingbezel

Style of bezel which rotates to measure elapsed time, dual timeand mathematical functions. These style bezels are normally designedfor and used on aviation and scuba diving watches.

rotor

Half round shaped weight which rotates inside a mechanical automaticwinding watch and winds the mainspring when the watch is worn. Rotorsare normally made of non-precious metals. However, some high gradewatches use precious metals like gold and platinum.

round

Style of watch case that is circular.

sapphire crystal

Synthetic watch crystal that is extremely hard and very scratch resistant.

self-winding

The watch mainspring is wound automatically by a device inside thewatch which rotates during normal wrist motion when the watch is worn.

setting

Procedure of rotating the winding and setting crown to bring the hands of a watch to the position of correct time.

shockresistant

A watch movement in which the balance staff end stonejewels are sprung so that when the watch is subjected to a shock, therewill be some 'give.'

SiderealDay

Actual time the earth takes to rotate once a day with the use of afixed star as a reference point. The measurement interval of time istaken between two successive transits of the same star over the samemeridian. A Sidereal Day is 3 hours and 56 seconds longer than the meantime of a solar day.

SiderealTime

Primarily used in observatories for the study of astronomy. Itis the time measured between two consecutive meridian transits of afixed star.

skeleton

A mechanical watch movement that has had as much material cut awayfrom the plates and dial as possible during the manufacturing process torender the greatest view possible of the watch wheels and escapement.It is normally cased in a watch case where the crystal is mounted onboth the front and back to create a very decorative watch.

SolarDay

The actual time the earth takes to rotate once a day with the useof the sun as a fixed point of reference. The measurement interval oftime is taken between two successive transits of the sun over the samemeridian.

Solar Time

The time of day determined by the sun. Example: the use of a sun dial to measure solar time.

split-secondchronograph

The feature or complication of a watch which allows youto measure fractions of a second and elapsed time by two separaterecording hands, independently of the watch displaying normal time.

spring bar

A spring-loaded metal bar which mounts between the case lugs for attaching the strap or bracelet to the case.

square

Style of watch case in which each of the four sides are equal size.

stem

The winding shaft that connects into the movement's winding andsetting mechanism. The winding crown is fitted to the opposite end ofthis shaft.

stemwind

Refers to the winding of a manual wind mechanical watch with theuse of a winding crown and stem attachment to the movement.

stopwatch

A timekeeping instrument used for the measurement of timeintervals in fractions of a second, such as those used at sportingevents.

strap

A piece of leather or synthetic material used for securing a watch to the wrist.

sub-dial

A smaller dial on the main dial of a watch displaying a feature ofthe watch. Example: constant second hand, minute and hour counters,days, dates, months, leap years, etc.

sub-seconds hand

A smaller sub-dial on the main dial displaying constant seconds.

sweep seconds hand

A seconds hand mounted in the center of the dial displaying constant seconds.

tachometer

Watch or stop watch used for the measurement of speed. Normally atimer or chronograph with a graduated dial or bezel allowing the speedof a vehicle to be figured in miles per hour or kilometers per hour.

tantalum

An extremely hard, metallic element which is gray in color and highlyresistant to corrosion. Used in the manufacture of watch cases andbracelets.

telemeter

A watch or stop watch used for the measurement of the distance anobject travels over a period of time. It is normally a timer orchronograph with a graduated dial or bezel, allowing the speed of anobject to be computed in kilometers or miles per hour wi

Time

Units of measurement of the rotation of the earth on its axis.

time zone

A portion of the earth's surface where the same time is agreed upon.

timepiece

A watch or clock which displays only the time of day.

timer

A timekeeping instrument used for the measurement of time intervalsin fractions of seconds, such as those used at sporting events.

titanium

A strong, lightweight metallic element, gray in color, which ishighly resistant to corrosion. It is used in the manufacture of watchcases and bracelets.

tonneau

Style of a rectangular or square wrist watch case that is wider(bowed outward) on the sides of the case in the center and tapers towardboth ends.

tourbillon

Self-compensating device designed to overcome various verticalposition timing errors. The entire escapement and balance assembly isfitted into a cage, and the complete assembly rotates every 60 seconds.

train

The series of wheels and pinions in a watch or clock comprised of theCenter Wheel, Third Wheel, Fourth Wheel and Escape Wheel. Themainspring band and balance assembly are not considered part of thetrain.

triple calendar

A complicated watch movement with a dial which displays the day, date and month.

tritium

A substance applied to hands and hour markers to make them luminous so they will glow in the dark.

U.T.C.

(Coordinated Universal Time)- The official measurement of timethroughout the world, completely independent of all time zones.

upand down indicator

A smaller sub-dial on a watch dial or a separateindicator which displays how much the mainspring is wound up or down.Normally, the dial or indicators read "up and down." 'Down' is the zerowound position. 'Up' is maximum wound position.

watch case

asymmetrical - A style of watch case that is irregular in shape.

watch case

coin - A watch case in which a coin is used as the case.

watch case

cushion - A style of square wrist watch that is wider (bowed outward) in the center of all four sides of the case.

watch case

round - A style of case that is circular.

watch case

square - A style of watch case in which each of the four sides are equal size.

watch case

tank - A style of rectangular wrist watch case design.

watchcase

tonneau - A style of a rectangular or square wrist watch casethat is wider (bowed outward) on the sides of the case in the center andtapers toward both ends.

waterproof

A design feature of a watch case made to withstand completesubmerging. Some waterproof watches are also designed to withstandextreme water pressures, as needed in watches used for scuba diving.

water resistant

A watch designed to withstand rain and splashes of water, but not designed to withstand submerging.

white gold

Yellow gold that is alloyed with palladium.

winding

Procedure to wind a watch mainspring. This can be done by rotatingthe winding crown on a manual wind watch or automatically by wearing awatch with a rotor winding system in an automatic winding watch.

windingcrown

A knob located on the outside of the watch case used forwinding the mainspring and setting the time and calendar functions.

World Time Watch

A type of watch which gives the time in different cities in the world by way of a moveable dial.

wrist watch

A watch designed to be worn on the wrist and held on by a strap band or bracelet.

Yacht-Timer

Style of watch used to count down a boat race.