Last Updated on Wednesday, 06 May 2009 21:41 Written by GoldSmithWatchWorks Monday, 11 August 2008 04:19

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, etc).

Applique Applique
applied characters are numerals or symbols cut out of sheet metal and stuck or riveted to a dial.

Automatic Watch
The watch mainspring is wound by movements or acceleration of the wearer's arm. A rotor turns and gears connected wind the spring. Invented in Switzerland by Abraham-Louis Perrelet in the 18th century.

Balance
Moving Wheel Part circular, that oscillates on an axis of rotation. A hairspring is coupled to it make it swing to and fro, thereby dividing time into exact equal parts. Each of the to-and-fro movements of the balance ("tick-tack") is called an "oscillation" with one oscillation composed of two vibrations.

Bar, lug
The metal BARS or RODS that extend from the wristwatch case for attaching the band.

Barrel
Thin cylindrical box housing the mainspring of a watch with a toothed rim that drives the "train".. [GEARS] .

Bridge Complementary
A part fixed to the main plate to form the frame of a watch movement. Parts are then mounted inside the frame (part of the "ébauche").

Calibre
Used to mean the size of a watch movement,
Denotes a type of movement (men's calibre, automatic calibre, etc).
Calibre number accompanied by a manufacturer's mark serves to indicate the watches origin.

Watch Case
The container that protects the watch-movement from dust, water and shock.
Provides the main appearance and denotes the fashion and type of watch.

Casing Up
Inserting and fixing a watch movement into its case.

Chablon French
term for a watch movement of which all or part of the components are not assembled.

Chronograph Watch
 Apparatus with two independent time systems indicating time of day and measuring brief intervals of time.
Counters registering seconds, minutes and hours and can be started and stopped as desired.
The term chronograph is different than chronometer.
Chronographs generally have a start/stop pusher and reset pusher. One touch of the start/stop pusher activates the separate chronograph hand. A second touch of the start/stop pusher stops the chronograph. Chronographs can measure durations of 12 hours, 29 minutes and 59 seconds.

Chronometer Watch which has undergone a series of precision tests in an official institute. The requirements are very severe: a few seconds per day in the most unfavourable temperature conditions (for mechanical watches) and positions that are ordinarily encountered. If the watch passes these tests, it is awarded with an official certificate verifying its ability to maintain accurate time in various positions. Once awarded a COSC certification, each watch manufacturer produces its own branded certificate.

Crown Knurled
knob located on the outside of a watch case and used for winding the mainspring. It is also used for setting the hands to the right time and for correcting calendar indications.

Date Ordinal
number referring to a day of the month.

Date-watch:
watch indicating the date, the month

Complicated date Watch
the above and the year, phases of the moon etc.

Names:
calendar-watch or calendar.
Perpetual calendar: watch indicating leap years as well as the date.

 Deployment  / Deployant

A clasp mechanism derived from the French adjective Deployant - which means to unfold, unfurl or spread out.
Commonly called Deployment, a clasp is an expanding metal clasp that permits both metal and fabric bracelets to close invisibly around the wrist.

Dial Indicating "
face or plate of metal or other material bearing various markings to show hours, minutes and seconds.

Direct-drive Refers to a seconds-hand that moves forwards in little jerks. Trotteuse, French term for a direct-drive seconds-hand, especially a centre seconds-hand.

Display 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 by mechanicalor electronic means.

Ebauche French
A movement blank 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 are not parts of the "ébauche".

The escape wheel and anchor.
Escapement Set of parts (escape wheel, lever, roller) which converts the rotary motion of the train into to-and-fro motion (the balance).

Etablissage French
term for the method of manufacturing watches and/or movements by assembling their various components: receipt, inspection and stocking of the "ébauche", the regulating elements and the other parts of the movement and assembling springing and timing; fitting the dial and hands; casing; and final inspection.

Etablisseur French term for a watch factory which  assembles watches without producing the components.

Factory,
In the Swiss Terms: watches are manufactured almost completely,

Fly-back Hand In a flyback chronograph where the center second hand may be stopped, reset to zero, and restarted with a single push of one of the chronograph pushers. Unlike traditional chronographs, the fly-back maintains timekeeping accuracy with no time is lost while the seconds hand returns to the zero position. The chronograph maintains the elapsed time during the reset.

Glass, Crystal Thin plate of glass or transparent synthetic material for protecting the dials of watche

Guilloché Guilloché is an ornamental dial pattern that repeats itself.

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.

The incabloc mechanism showing the gold-colored Incabloc spring

Incabloc Incabloc is a  shock-absorbing mechanism of the same name used in mechanical wristwatches to prevent damage to sensitive parts during a flat or lateral fall. It protects the pivots and balance-jewels by keeping the distance between the jewels constant.

Jewel Bearing, endstone or pallet used for reducing friction. Generally made of synthetic materia.

Main Plate Base plate on which all the other parts of a watch movement are mounted

mainspring
The mainspring stores winding energy to operate the watch between windings. It is a long strip of hardened blued or alloyed steel. The mainspring is coiled inside the barrel and enables mechanical watches to run for 24 to 45 hours. 

Manufacture d'horlogerie French term for a watch factory which itself produces the components needed for the manufacture of its product.

Marine Chronometer Highly accurate mechanical or electronic timekeeper enclosed in a box , 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.

Middle
  Miiddle part of the case where the movement is fitted.

Movement Assembly
the winding and setting mechanism, the mainspring, the train, the escapement, the regulating elements. The movement consists of the "ébauche", the regulating elements and the other components.

Regulating Elements Set of parts comprising the regulating system (sprung balance) and the escapement (escape wheel, lever and roller).

The repeater runs parallel to the outer circumference of the case. It looks like a metal railing.

Repeater Watch that strikes the hours by means of a mechanism operated by a push-piece or bolt.

Rotor 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.

Setting
Process of bringing the hands of a watch or clock to the position corresponding to exact time.

Shock Absorber Resilient
bearing  intended to take up the shocks received by the balance staff and thus protects its pivots from damage.

Skeleton
Skeleton watch: watch case that show various parts of the movement, enabling the main parts of the watch to be seen.

Stopwatch
Timekeeping instrument which can be used for measuring intervals of time.

Striking-work,
Striking-Mechanism In a watch or clock, automatic or hand-operated mechanism that strikes the hours, etc, or rings an alarm-bell).

Tachometer
Instrument for measuring speed. In watchmaking, a timer or chronograph with a graduated dial on which speed can be read off in kilometres per hour or some other unit.

Terminage
French term denoting the process of assembling watch parts for the account of a producer.

Termineur French term for an independent watchmaker (or workshop) engaged in assembling watches, either wholly or in part, for the account of an "établisseur" or a "manufacture", who supply the necessary loose parts.

Timer Instrument used for registering intervals of time (durations, brief times), without any indication of the time of day.

Breguet Tourbillon escapement

Tourbillon
Device invented to eliminate errors of rate in the vertical positions. A mobile carriage or cage carries all the parts of the escapement with the balance in the center. The escape pinion turns about the fixed fourth wheel. The case makes one revolution per minute, thus annulling errors of rate in the vertical positions.

Vibration Movement
  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).

Watch Material
Loose parts, components either for producing watches or for repairing them.

Water Resistant
Made to prevent water/moisture from entering watch-case.

Winding Operation
tightening the mainspring of a watch by means of the crown) by hand or automatically by means of a rotor .