Dials found in various watches have apertures (small windows) in which certain indications are given (e.g. date, hour, etc.).
Assembling is the process of piecing together the components of a movement. Historically assembling has been done entirely by hand, though the process has largely automated in recent years.
The French term for the parts used for making an escapement.
Invented in Switzerland by Abraham-Louis Perrelet in the18th century, this type of watch is wound kinetically by movements of the wearer’s arm. It employs the principle of terrestrial attraction: a rotor turns and transmits its energy to the spring by means of an appropriate mechanism. Moving parts consist of a circular balance that oscillates around its axis of rotation. . The balance is joined to a hairspring that allows it swing to and fro, dividing time into exactly equal parts. Each of the to-and-fro movements of the balance (“tick-tack”) is called an “oscillation”. One oscillation is composed of two vibrations.
The thin metal rod fixed between the horns, for attaching the wristlet found in wristwatch-cases.
The thin cylindrical box that contains a watch’s mainspring. The toothed rim of the barrel drives the train.
This is an endstone or pallet employed for reducing friction. Usually, bearings are made of synthetic material. Precious or semi-precious stones – rubies and sapphires – are often used as bearings in high-end watches.
The bridge is a complementary part fixed to the main plate that forms the frame of a watch movement. The other parts are mounted inside the frame (this is part of the “e’bauche”).
This term indicates a type of movement (men’s calibre, automatic calibre, etc). When a calibre number is accompanied by the manufacturer’s mark, it denotes its origin. Originally caliber defined the size of a watch movement.
The container that protects the watch-movement from dust, damp and shocks. It also offers a watch’s aesthetic.
The process of inserting and fixing a watch movement into its case.
A French term for a watch movement in which all or some of the components are not fully assembled. (Not including the hands and dial.)
This is a timepiece or some other piece of apparatus containing two independent time systems: one that indicates the time of day, and the other measures intervals of time. Counters registering seconds, minutes and hours have the ability to be started and stopped, thereby making it possible to measure an exact duration of time. A Chronograph should not to be confused with a stopwatch.
A chronometer is a watch that has undergone a series of precision tests in an official institute.
The crown is the knob located on the outside of a watchcase. It’s used for winding the mainspring and for setting the hands to the right time, as well as for correcting the calendar indications.
A date-watch that indicates the date, and sometimes, the month, the year and the phases of the moon. Also referred to as “calendar-watch” or “calendar.”
The face or “plate” (usually made of metal), bears markings to show the hours, minutes and seconds.
This refers to a second-hand that moves forward in small increments.
A display is an indication of time or other data, either through analogue display, digital or numerical display.
Ebauche is a French term for a movement blank that is sold as a set of loose parts. Typically, it is comprised of the main plate, the train, the bridges, the winding and setting mechanism and the regulator.
The escapement is a set of parts comprised of the escape wheel, and the lever and roller — which converts the rotary motion of the train into back-and-forth motion, known as the balance.
This is a French term that describes the method of manufacturing watches and/or movements.
A French term for a watch factory that doesn’t actually manufacture the components, but only assembles them.
In the Swiss watch industry, the term manufacture is used for factories in which watches are manufactured almost completely
A thin plate of glass or plastic material used for protecting the dials of watches and clocks.
The hand is an indicator made of a thin piece of metal, which moves over a graduated dial. Most often three hands (showing the hours, minutes and seconds) are employed.
This is the base plate on which all the other parts of a watch movement are mounted. It is considered part of the “e’bauche.
The source of energy that powers a mechanical watch. The driving spring is found in the barrel of a watch or clock.
A French term for a watch factory that produces the components (in particular, the “e’bauche”) needed for the manufacture of watches and clocks.
This term refers to a highly accurate mechanical or electronic timepiece, enclosed in a box, and used for determining the longitude on board ships.
Middle (of watch-case)
Refers to the middle part of the case, in which the movement is fitted.
An assembly consisting of the principal elements of a watch or clock: chiefly, the winding and setting mechanism, the mainspring, the train, the escapement, and the regulating elements. “Anatomically”, the movement consists of the “e’bauche”, and the regulating elements.
A watch that strikes the hours by means of a mechanism operated by a bolt or push-piece. An example being a quarter-repeater: This timepiece sounds a low tone for the hours and a “ding-dong” for each of the quarters.
The half-disc of heavy metal, which is made to rotate inside the case of an automatic watch by the energy produced by the wearer’s movements. Its weight usually brings the rotor back to the vertical position. Its rotations continually wind the mainspring of the watch.
A basic unit of time, corresponding to one 86,000th part of the mean solar day.
Setting (to time)
The positioning of the hands of a watch or clock to the corresponding time desired.
A resilient bearing in a watch that is intended to take up the shocks received by the balance staff, thereby protecting its delicate pivots from damage.
A watch in which the case and various parts of the movement are made of transparent material, enabling the main parts of the watch to be visible.
A timekeeping instrument often used for measuring intervals of time.
The mechanism that strikes the hours, etc, or rings an alarm-bell in a watch or clock.
An instrument used for measuring speed. In watch making, this is a timer or chronograph with a graduated dial on which speed can be read off in miles or kilometers per hour (or some other unit).
French term indicating the process of assembling watch parts for the account of a producer.
French term for an independent watchmaker (or workshop) who assembles watches, either wholly or in part, for the account of an “e’tablisseur” or a “manufacture”, who supplies the requisite loose pieces.
An instrument for registering intervals of time without an indication of the time of day.
A device invented to eliminate errors of rate in the vertical positions.
The movement of an oscillating element (often a pendulum) that’s limited by two consecutive extreme positions. The balance of a mechanical watch usually makes five or six vibrations per second, but that of a high frequency watch may make up to ten vibrations per second.
Loose watch components for producing or repairing watches.
A watch designed to prevent water from entering.
Tightening the mainspring of a watch, either by hand or automatically.