The fine setting of a watch with a mechanical oscillation system. There are different procedures and qualities:

In normal adjustment, the daily rate of the wristwatch is measured with "face up" and »crown up« and is set to a time error of no more than 30 seconds.

Adjustment can be carried out in 2, 5 or 6 positions, such as

  • horizontal: »face up« (FU), »face down« (FD) and
  • vertical: »crown up« (CU), »crown left« (CL), »crown right« (CR), »crown down« (CD).

In the case of temperature compensation adjustment, the daily rate is measured and adjusted for 24 hours each at 4°, 20° and 36° C.


The setting or regulation of a watch.


Small, toothed cylindrical housing in which a rolled-up - and thus energy-storing - spring is located.


The holes for the pegs of the train. In fine wrist- and pocket watches, but also in clocks, the holes are equipped with bearing jewels especially for the quickly rotating wheels and pinions.


Decorative edge breaking on the bridges, cocks or steel parts of very fine mechanisms. Edges of a ground surface, sloped to 45 degrees while precisely maintaining the width, and then polished.


The upper part of the housing. The bezel has a seam into which the watch glass and seal are pressed.


The controlled oxidation of steel screws and other steel parts (such as watch hands) is called bluing. Bluing requires a great deal of dexterity and experience. The surface takes on the desired color at nearly 300° C.


A brass or German silver plate lying on two or more points on the basic plate and fastened there using adjusting pins and screws. The pins and wheels turn between the bridge and the plate.


Mechanism with several bridges to support the nest of gearwheels.

Contrôle Officiel Suisse des Chronomètres

Contrôle Officiel Suisse des Chronomètres (Swiss Chronometer Control Office). A Swiss national authority headquartered in La Chaux-de-Fonds, with offices in Biel, Geneva and Le Locle; all of these carry out official chronometer examinations and issue the corresponding certifcates regarding the daily time error. The C.O.S.C. exists since 1973.


The dimension and form of a mechanism and its parts. The specification of the caliber on the mechanism permits precise identification. So-called manufactory calibers are to be differentiated from the factory-made movement blanks of ébauche suppliers. The former are mechanisms that manufactories produce for their own use.

Casing ring

A ring made of metal (or plastic in the case of low-quality watches) that fills the space between the housing and the mechanism and which braces the mechanism and protects it from mild jolts.


A circular, drilled piece of metal to incorporate a bearing jewel.


A watch with additional functions that make it possible to start and stop a second hand, as well as to bring it back to its initial position, regardless of the mechanism itself.


A precision timepiece whose accuracy has been proven within the framework of a 15-day test at an official timepiece inspection office (e.g. the COSC in Switzerland). The mean daily time error may be no more than 4 seconds less and 6 seconds more than the actual time for the five positions  »crown left, crown up, crown down, face up, face down«.

Circular graining

A special cloudy ornamentation on plates, bridges and cocks.


A mechanical watch does a great deal of work. Therefore, it should undergo qualified servicing after no more than four years. If maintenance is not carried out, the sensitive cones of the train can be damaged.


A cock is a part of the frame; it lies on one side on top of the basic plate and is fastened there by a screw. It is used to incorporate bearing pads for movable parts, such as the pallet fork and the balance.


Additional mechanism for mechanical watches. The most important complications include a large date display, a power reserve indication, a perpetual calendar, a tourbillion, a striking mechanism, etc.


A grooved wheel located on the side of the housing, used to set the time and date and/or to tighten the main spring. A screwed-on crown, a simple O-ring crown as well as a bi-O-ring crown are most common among waterproof watches.

Daily rate

The daily rate is the difference between two watch readings taken 1 day apart.

Date display

The date is displayed either in analog form with a hand or digitally with a printed disc. The hand and the disc turn once around their axis within 31 days.  Everyday around midnight, the hand fitting moves them one position further.


Wristwatches with a digital date display have a date disc that is attached to the front of the mechanism. The numbers can be seen through a cutout in the face. There is a fundamental difference between gradual and jumping date displays. The former are advanced bit by bit by the mechanism. Jumping displays successively remove energy from the mechanism during the course of the day and store it in a spring. The energy is released precisely at midnight for the switching operation.


Almost all date displays in mechanical watches share the fact that they need to be corrected manually in months with less than 31 days.



The cutting of e.g. watch hand facets using rotating diamonds. Diamond-working results in surfaces polished to a glossy shine that reflect incident light especially well.


Movement blank with no escapement and mainspring.


French term for escapement.


Escape wheel

First element of the escapement and and simultaneously the last wheel of a train.


The mechanism with which the energy of the main spring is passed on in little jolts to the oscillating system of the watch; it prevents the mechanism from running down uncontrollably. At a frequency of 28,800 alternations/hour, it allows the train to move forwards 691,200 times per day. Over the course of four years, this results in more than one billion impulses.

Fine adjustment

A mechanism for setting the regulator in small amounts. A variety of different designs is used, such as gooseneck fine adjustment or the system with an eccentric screw. Fine adjustment does not necessarily result in higher precision. This is also accomplished with normal regulator pointers and dexterity.


Final machining of a watch.


The oscillations per unit of time, measured in Hertz (Hz). To increase precision, the number of alternations has been raised to 21,600 A/h (3 Hz), 28,800 A/h (4 Hz) or even 36,000 A/h (5 Hz). However, greater energy consumption is also a result of a higher frequency.

Geneva seal hallmark

A quality award of the city of Geneva originating in 1886. In 1957 and 1994, the regulations were revised; they now primarily cover twelve specifications for the precise machining and adjustment of mechanism parts, but without an accuracy test. Only watches that have been assembled and set in the canton of Geneva are eligible.

Genevese stripes (Cotes de Genève)

Oft-used rib-like decoration on the bridges and cocks of fine-caliber mechanisms.

German silver

Corrosion-resistant alloy of copper, nickel and zinc, with a very high rigidity. It is used to produce plates and bridges in high-quality mechanisms. As opposed to brass, subsequent galvanic processing of the material is not required. However, since errors in machining cannot be concealed using this method, high precision is required in the production of the mechanisms.

Glucydur balance

Modern balance which replaced the bimetallic compensation balance after the invention of the autocompensating balance spiral. Glucydur balances consist of a copper alloy containing approx. three percent beryllium; this can be seen by its gold-colored appearance. On the other hand, more simple nickel balances have a silver tint. Glucydur balances have a hardness of 380 Vickers (nickel balances = 220, brass balances = 180). As a result, they are excellent for riveting, balancing and fine regulation.


Greenwich Mean Time - The time (UTC, Universal Time Coordinated) at the zero meridian in Greenwich. Greenwich Mean Time is used today as the standard in navigation and international radio communications.

Grande Complication

Highly complicated pocket watch or wristwatch that has at least the following functions: a chronograph, a perpetual calendar and minute repetition.


The engraving of a regular, sinuous or linear pattern onto metal with the help of templates and a graver. The guillochee machine was invented in the 15th century by an unknown master. In the 19th century, guillocheeing was a trade of its own. Guillocheeing is a combination of machine and manual engraving.

Hand fitting

A train located between the plate and the face that transfers the turnings of the minute gear shaft to the hour hand.

Together with the hand adjustment system, it permits the hour and minute hands to be set using the pulled-out crown.

Hand-wound watch

A timepiece whose main spring is wound by hand..


One of the most common and widely used shock absorbers for mechanical watches. »Incabloc« is viewed as the most successful shock absorber in the history of portable timepieces.


In a mechanism, this is used to reduce friction and wear. These functional stones were made from real rubies and diamonds in the past. Synthetic rubies are used today.


Synthetic rubies that reduce wear and friction on the wheels.


International designation for the bearings in a mechanism.


A unit of weight. One kt = 200 milligrams (mg).


The Paris ligne is an old length of measure that was used as a reference unit throughout Europe in the 17th and 18th centuries. One Paris ligne corresponds to 144 French feet. Based on the final definition of the meter of 1799, the Paris ligne equals 9,000,000 ÷ 27,706 ÷ 144  ?  2.255829 millimeters. This reference measure was used by scientists such as Newton, by watchmakers, by typesetters and in historic metrology.

Main spring

Spring for storing the winding energy.


In the original sense, a manufacture is an operation that is somewhere between a workshop and a factory. In the timepiece industry, the term manufacture is used for manufacturers who produce a majority of the most important individual parts of watches - primarily parts of the mechanism - themselves.


Another term for mechanism.


An alloy of iron, nickel, chrome, titanium and beryllium that is used to make balance spirals that are distinguished by their good antimagnetic and temperature-compensating properties.

Number of alternations

The number of alternations is the number of beats of a rate-regulating organ (e.g. a pendulum or balance). Two alternations result in a full oscillation.

Oscillating weight

An oscillating weight that turns without limits in watches with automatic winding. Depending on the design of the self-winding mechanism, the main spring is tensioned in one or both rotor turning direction(s). Differentiation is made between central and micro rotors. The former turn around the entire mechanism, while the latter are integrated in the level of the mechanism.

Pallet fork

Part of the escapement that prevents the train from running uncontrollably. This causes the characteristic ticking of a mechanical watch..

Perpetual calendar

In addition to the normal time (hours, minutes and seconds), the date, weekday, month and year are also displayed, taking into account leap years, month lengths and phases of the moon.

Perpetual calendar

This automatically takes the varying lengths of the months until 2100 into account.


A gear for transferring energy, with more than 6 but less than 20 teeth.


Metallic bottom plate that supports the bridges, cocks and other components of a mechanism.


The surfaces or edges of watch components are ground and polished with the help of a lapidary (polishing machine). This improves the visual appearance and value of a mechanism.

Power reserve
Energy potential over 24 hours

The energy potential that extends over the normal winding interval of a wristwatch (24 hours). The power reserve is usually approximately 10-16 hours.

Power reserve indication

An indication of the remaining running time for mechanical timepieces.

Due to the technical effort, power reserve indications could and still can be found only in wristwatches of upmarket classes.

Ratchet wheel

A part of a watch's winding system.


A complete (subsequent) test of a finished watch before it leaves its place of manufacture. This also includes a check of the daily rate.


An oscillating weight that turns without limits in watches with automatic winding. Depending on the design of the self-winding mechanism, the main spring is tensioned in one or both rotor turning direction(s). Differentiation is made between central and micro rotors. The former turn around the entire mechanism, while the latter are integrated in the level of the mechanism.


In a mechanism, rubies are used to reduce friction and wear. These functional stones were made from real rubies and diamonds in the past. Synthetic rubies are used today.

Running time

The total running time of a mechanical mechanism between its being wound completely and it stopping because the main spring has run down.

Sapphire crystal

Scratchproof watch glass with a hardness of 9 (Mohs). Only diamonds have a greater hardness.

Satin finishing

A fine, satiny and matte finish on metal surfaces.

Screwed case back

A threaded case back that is screwed into the watch housing.


A term for automatic winding in mechanical watches.


A rotating oscillating weight (rotor) that is put into motion by the movements of the watch on the wearer's wrist, causing the mechanism to wind itself.

Small second

A display of seconds that is decentral, i.e. not in the middle of the face.

Spring bar

Thin tube for attaching a strap between the strap abutments. A spring within the tube presses the two conical ends outwards so that they can lock into the corresponding holes in the «horns» on the housing.

Stop second

When the crown is pulled up, the balance - and thus the motion of the second hand - is stopped. In this way, the time can be set to the second..


A small piece of metal in which the outer end of the balance spiral is pinned or – in modern mechanisms – glued. The stud itself is attached to the balance cock or the plate.


A new fluorescent compound that has found recent use as a replacement for tritium for marking hands and indices.

Sweep second

A second hand located in the center of the face.

Swiss escapement

A free escapement for small watches where the teeth of the escape wheel extend outwards like pistons. As a result, the load is distributed over the escape wheel and the pallet fork, with its two (ruby) pallets. In addition to the Swiss escapement, there are also English and Glashütte escapements.

Swiss Made

The indication of the country of origin on the face and/or the mechanism of a »Swiss wristwatch«. According to the »Swiss Made« ordinance of May 27, 1992 this indication of the country of origin may be used if the mechanism is Swiss and if assembly, sheathing and the final inspection take place in Switzerland. Swiss watches are those whose components from Swiss manufacturers make up at least 50 percent of the watch's value, not taking assembly costs into account. Non-Swiss manufacturers may not use »Swiss Made« if assembly is not carried out in Switzerland, even if all components come from Switzerland.

Three-quarter plate

As opposed to the bridgework, nearly the entire train (exceptions: pallet fork, escape wheel and balance) is located below the plate, resulting in high stability.


A design - invented by Abraham-Louis Breguet in 1795 and patented in 1801 - to compensate for the center-of-gravity displacement in the oscillation system (balance and balance spiral) in mechanical timepieces. In the tourbillion (»whirlwind«), the entire oscillation and escapement system is housed in a cage that is as light as possible. This rotates once around its axis within a prescribed time span (usually one minute). In this manner, the effects of gravity are compensated when a watch has a vertical orientation; the accuracy is also improved. In the horizontal orientation, however, tourbillion has no influence on precision.


All the wheels and pinions that transfer the momentum from the barrel to the escapement wheel.

This includes: 

  • center wheel
  • third wheel
  • fourth wheel
  • escapement wheel



Water-resistant wristwatches

The term »water-resistant« is specified in DIN standard 8310. Accordingly, a watch is said to be water-resistant if it passes the pressure test according to DIN 8310 when it is new:

30 minutes with a 1 m water column (~ approx. 1 bar), then 90 seconds with a 20 m water column (~ approx. 2 bar)

Furthermore, DIN 8310 stipulates: »The manufacturer and distributor of water-resistant wristwatches must provide instructions for use with each wristwatch...«

The designation »water resistant« applies to watches that are resistant to sweat, spraying water and rain. In addition, no moisture can penetrate the watch for at least 30 minutes at a depth of one meter.

The supplement 50 m, 5 bar or 5 atm is not regulated; however, it indicates that these watches were subjected to a corresponding test pressure. Nevertheless, it is not a good idea to go swimming, not to mention diving, with such watches.