Aperture Small opening. The dials of some watches have apertures in which certain indications are given (the date, the hour, etc ).
Applique Applique or applied chapters are numerals or symbols cut out of a sheet metal and stuck or riveted to a dial.
Assembling Process of fitting together the components of a movement. This was formerly done entirely by hand, but the operations have now been largely automated. Nevertheless, the human element is primordial, especially for inspection and testing.
Automatic watch A watch whose mainspring is wound by the movements or accelerations of the wearer’s arm. On the basis of the principle of terrestrial attraction, a rotor turns and transmits its energy to the spring by means of an appropriate mechanism. The system was invented in Switzerland by Abraham-Louis Perrelet in the 18th Century.
Balance Moving part, usually circular, oscillating about its axis of rotation. The hairspring coupled to it makes it swing to and from, dividing time into exactly equal parts. Each of the to and from movements of the balance (“Tick-tack”) is called an “oscillation”. One oscillation is composed of two vibrations.
Bar, lug In wristwatch-cases, a thin metal rod fixed between the horns, for attaching the wristlet.
Barrel Thin cylindrical box containing the mainspring of a watch. The toothed rim of the barrel drives the train.
Bezel The bezel is either snapped or screwed into the case and often holds the crystal in place. Bezels can be functional for diving and timing or purely aesthetic, such as a diamond bezel.
Bracelet Usually made of a metal or in combination with another material such as leather or ceramic that keeps your timepiece securely attached to the wrist.
Bridge Complementary part fiexed to the main plate to form the frame of a watch movement. The other parts are mounted inside the frame.
Calibre Originally used to mean the size of a watch movement, this term now denotes a type of movement (men’s calibre, automatic calibre, etc). When a calibre number is accompanied by the manufacturer’s mark, it serves as an indication of orgin.
Case Container that protects the watch-movement from dust, damp and shocks. It can be made from different metals and in different shapes depending on fashion trends.
Chronograph Watch or other apparatus with two independent time systems: one indicates the time of day, and the other measures brief intervals of time. Counters registering seconds, minutes and even hours can be started and stopped as desired. It is therefore possible to measure the exact duration of a phenomenon. Not to be confused with the timer, the stopwatch and the chronometer. The most desired chronograph in the world is the Rolex Daytona.
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 unfavorable temperature conditions (for mechanical watches) and positions that are oridinarily encountered.
COSC Acronym for Controle Officiel Suisse des Chronometres, the COSC is the preeminent Swiss institution that tests the precision and functioning of chronometer movements. Testing each movement in different positions, temperatures, and hypothetical situations, these experts issue a chronometer certificate and a functioning bulletin for each watch, allowing a maximum gag of plus-four or minu-four seconds per day.
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 the calendar indications.
Crystal Thin plate of glass or transparent synthetic material, for protecting the dials of watches.
Date Ordinal number referring to a day of the month: the 15th October. Date-watch: watch indicating the date, the month and sometimes the year and the phases of the moon. Also called a calendar-watch or calendar. Perpetual calendar: watch indicating leap years as well as the date.
Deployant Buckle A deployant, or fold-over clasp, is an elegant conveinance that allows for perfect strap closures through interlocking metal pieces, eliminating the need for strap holes. It is considered safer to wear because if the buckles releases, the watch is still attached to the wrist.
Dial Indicating “face” or plate of metal or other material, bearing various markings to show, in ordinary watches, the hours, minutes and seconds. Dials vary much in shape, decoration, material, etc. The indications are given by means of numerals, divisions or symbols of various types.
Display Indication of time or other data, either by means of hands moving over a dial (analog display) or by means of numerals appearing in one or more windows (digital or numerical display): these numerals may be completed by alphabetical indications or by signs of any other kind. Such displays can be obtained by electronic means.
Fly-back Hand In a chronograph with analog display, an additional centre second hand which can remain superposed on the other one as it moves, can be stopped independently and then made to “fly back” so as to catch up with the other hand, can be stopped and reset to zero together with the other hand. In chronographs with numerical display, a “function” having the same effect.
Hand Indicator, usually made of a thin, light piece of metal, very variable in form, which moves over a graduated dial or scale. Watches usally have three hands showing the hours, minutes and seconds.
Jewel Bearing, endstone or pallet used for reducing friction. Generally made of synthetic material, except for the precious or semi-precious stones (ruby, sapphire, garnet) which are sometimes used in luxury watches.
Mainspring The driving spring of a watch, contained in the barrel.
Movement Assembly consisting of the principal elements and mechanisms of a watch: the winding and setting mechanism, the mainspring, the train, the escapement, the regulating elements.
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.
Shock absorber Resilient bearing which, in a watch, is intended to take up the shocks received by the balance staff and thus protects it delicate pivots from damage.
Skeleton A watch in which the case and various parts of the movement are of transparent material, enabling the main parts of the watch to be seen.
Stopwatch 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.
Tachometer Instrument for measuring speed. In watchmaking, a timer or chronograph with a graduated dial on which speed can be read off in kilometers per hour or some other unit.
Timer Instrument used for registering intervals of time (durations, brief times), without any indication of the time of day.
Tourbillon Device invented to eliminate errors of rate in the vertical positions. It consists of a mobile carriage or cage carrying 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.
Water Resistant Made to prevent water from entering. Water-resistant case, watch-case whose joints are made to prevent moisture from entering.
Winding 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 wearer’s arm).
Glossary
Aperture Small opening. The dials of some watches have apertures in which certain indications are given (the date, the hour, etc ).
Applique Applique or applied chapters are numerals or symbols cut out of a sheet metal and stuck or riveted to a dial.
Assembling Process of fitting together the components of a movement. This was formerly done entirely by hand, but the operations have now been largely automated. Nevertheless, the human element is primordial, especially for inspection and testing.
Automatic watch A watch whose mainspring is wound by the movements or accelerations of the wearer’s arm. On the basis of the principle of terrestrial attraction, a rotor turns and transmits its energy to the spring by means of an appropriate mechanism. The system was invented in Switzerland by Abraham-Louis Perrelet in the 18th Century.
Balance Moving part, usually circular, oscillating about its axis of rotation. The hairspring coupled to it makes it swing to and from, dividing time into exactly equal parts. Each of the to and from movements of the balance (“Tick-tack”) is called an “oscillation”. One oscillation is composed of two vibrations.
Bar, lug In wristwatch-cases, a thin metal rod fixed between the horns, for attaching the wristlet.
Barrel Thin cylindrical box containing the mainspring of a watch. The toothed rim of the barrel drives the train.
Bezel The bezel is either snapped or screwed into the case and often holds the crystal in place. Bezels can be functional for diving and timing or purely aesthetic, such as a diamond bezel.
Bracelet Usually made of a metal or in combination with another material such as leather or ceramic that keeps your timepiece securely attached to the wrist.
Bridge Complementary part fiexed to the main plate to form the frame of a watch movement. The other parts are mounted inside the frame.
Calibre Originally used to mean the size of a watch movement, this term now denotes a type of movement (men’s calibre, automatic calibre, etc). When a calibre number is accompanied by the manufacturer’s mark, it serves as an indication of orgin.
Case Container that protects the watch-movement from dust, damp and shocks. It can be made from different metals and in different shapes depending on fashion trends.
Chronograph Watch or other apparatus with two independent time systems: one indicates the time of day, and the other measures brief intervals of time. Counters registering seconds, minutes and even hours can be started and stopped as desired. It is therefore possible to measure the exact duration of a phenomenon. Not to be confused with the timer, the stopwatch and the chronometer. The most desired chronograph in the world is the Rolex Daytona.
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 unfavorable temperature conditions (for mechanical watches) and positions that are oridinarily encountered.
COSC Acronym for Controle Officiel Suisse des Chronometres, the COSC is the preeminent Swiss institution that tests the precision and functioning of chronometer movements. Testing each movement in different positions, temperatures, and hypothetical situations, these experts issue a chronometer certificate and a functioning bulletin for each watch, allowing a maximum gag of plus-four or minu-four seconds per day.
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 the calendar indications.
Crystal Thin plate of glass or transparent synthetic material, for protecting the dials of watches.
Date Ordinal number referring to a day of the month: the 15th October. Date-watch: watch indicating the date, the month and sometimes the year and the phases of the moon. Also called a calendar-watch or calendar. Perpetual calendar: watch indicating leap years as well as the date.
Deployant Buckle A deployant, or fold-over clasp, is an elegant conveinance that allows for perfect strap closures through interlocking metal pieces, eliminating the need for strap holes. It is considered safer to wear because if the buckles releases, the watch is still attached to the wrist.
Dial Indicating “face” or plate of metal or other material, bearing various markings to show, in ordinary watches, the hours, minutes and seconds. Dials vary much in shape, decoration, material, etc. The indications are given by means of numerals, divisions or symbols of various types.
Display Indication of time or other data, either by means of hands moving over a dial (analog display) or by means of numerals appearing in one or more windows (digital or numerical display): these numerals may be completed by alphabetical indications or by signs of any other kind. Such displays can be obtained by electronic means.
Fly-back Hand In a chronograph with analog display, an additional centre second hand which can remain superposed on the other one as it moves, can be stopped independently and then made to “fly back” so as to catch up with the other hand, can be stopped and reset to zero together with the other hand. In chronographs with numerical display, a “function” having the same effect.
Hand Indicator, usually made of a thin, light piece of metal, very variable in form, which moves over a graduated dial or scale. Watches usally have three hands showing the hours, minutes and seconds.
Jewel Bearing, endstone or pallet used for reducing friction. Generally made of synthetic material, except for the precious or semi-precious stones (ruby, sapphire, garnet) which are sometimes used in luxury watches.
Mainspring The driving spring of a watch, contained in the barrel.
Movement Assembly consisting of the principal elements and mechanisms of a watch: the winding and setting mechanism, the mainspring, the train, the escapement, the regulating elements.
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.
Shock absorber Resilient bearing which, in a watch, is intended to take up the shocks received by the balance staff and thus protects it delicate pivots from damage.
Skeleton A watch in which the case and various parts of the movement are of transparent material, enabling the main parts of the watch to be seen.
Stopwatch 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.
Tachometer Instrument for measuring speed. In watchmaking, a timer or chronograph with a graduated dial on which speed can be read off in kilometers per hour or some other unit.
Timer Instrument used for registering intervals of time (durations, brief times), without any indication of the time of day.
Tourbillon Device invented to eliminate errors of rate in the vertical positions. It consists of a mobile carriage or cage carrying 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.
Water Resistant Made to prevent water from entering. Water-resistant case, watch-case whose joints are made to prevent moisture from entering.
Winding 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 wearer’s arm).