Scratch-resistant material, having a hardness of 9 on the Mohs scale, used for watch glass. Only diamond is harder than sapphire.

A matt, silky, fine polish given to metal surfaces.

Calibrations of a production counter help determine the production capacity of identical parts in a mass-produced item. The chronograph is started at the beginning of the process leading to the production of a mass-produced part in a series, then stopped again at the end of the process. The hand on the dial shows how many pieces were produced per hour. This assumes, however, that no more than 60 seconds are required to produce each part.

The duration of a” diminutive secunda pars“, that is, a” diminished second part " of an hour, has been redefined several times throughout history. These redefinitions were due in part to the enormous advances made in the science of time measurement. A committee composed of French scientists suggested in 1820 that a second should be defined as an 86,400 th of an average solar day. The irregularity of the Earth rotation determined empirically, together with advances in modern quartz timekeeping technology, has made this definition obsolete. A new definition was proposed in 1956, when the unit of time known as the "second" was redefined as 31,556,925.9747 th of the time it took the Earth to complete an annual orbit of the sun. Noon on January 1st of 900, was chosen as the time to begin counting these annual orbits. This minutely defined unit, however, did not survive very long because it was too inaccurate. A five-second detour would accumulate over a single millennium. Quartz timekeepers ceased to play a role in the shattering world of highly precise time measurement because they were replaced by atomic clocks in the late 50s, so scientists set themselves the task of finding a new definition. Since 1957, the second has been defined as the time it takes for the electronic hull of a cesium atom to complete 9,192,631,770 vibrations.

First introduced by Jost Bürgi in 1579, seconds were originally only displayed on very accurate watches. Today, a seconds hand is practically useless on watches and alarm clocks of all kinds.

A clock that correctly indicates the varying lengths of the months during a leap year cycle. The 29 February is unknown to it because it is missing a wheel that turns around its axis once every four years.

Circular piece of moulded metal with a slot to hold a jewel. To secure the setting to its bar (bridge), it is pressed or screwed into the bar. The original purpose of the setting was mainly aesthetic. Made of gold or a gold-like metal, settings were used to enhance the lustre and effect of beautiful jewellery. It was only later that watchmakers discovered the pragmatic purpose of settings. The jewel within a factory setting can easily be replaced if the stone breaks. In the wake of the automated production of watch movements, settings became increasingly common. Stamps could precisely drill holes in the bridge to accept settings. Settings became pointless after jewellery manufacturers became able to supply their products with absolutely impeccable quality and exactly identical dimensions. This jewellery could be pressed directly into holes drilled in bridges, rods and plates. Today, screwed settings are used because of their attractive appearance. They are most often found in movements made by watch manufacturers in Glashütte.

A watch movement that is not circular. A wide range of movements of various shapes (e.g., tonneau-shaped, baguette-shaped, rectangular) have been developed, especially for use in wristwatches. Shaped movements have become quite rare nowadays.

A watch that measures and supports the immediate reading of the duration of short intervals. By definition, such devices include chronometers and chronographs.

A watch movement whose plate, bridges, taps, barrel, and sometimes even rotor are pierced so that the only material remaining is that which is absolutely essential to the function of the skeletonized component. The elaborate piercing allows one's gaze to penetrate deep into (and sometimes through) the movement. Skeleton work is done manually and requires a highly skilled watchmaker. The quality of craftsmanship is most easily recognized in skeleton work at the points where the faceted edges meet. Three different types of angles can be differentiated: 1. The inserted corner. Two facets meet to form a recessed corner. The joint should be a perfectly straight line connecting the intersection points of the two edge lines. This type of corner, which can only be created by hand, shows that the skeleton work is of the highest quality. 2. The protruding corner. The joining of two facets forms a protruding corner. This corner should have a sharp edge and should be neither beveled nor rounded. 3. The rounded corner. Unlike the previous two shapes, the facet here does not have a sharp edge. Rounded corners are less artistic and less valuable than the other two types of corners because machines can also be used to create them. Wristwatches with skeletonized movements debuted in the mid-1930s. Rounded corners are less artistic and less valuable than the other two types of corners because machines can also be used to create them. Wristwatches with skeletonized movements debuted in the mid-1930s. Rounded corners are less artistic and less valuable than the other two types of corners because machines can also be used to create them. Wristwatches with skeletonized movements debuted in the mid-1930s.

Steering device for a chronograph. A mobile cam, the shape of which varies depending on the particularities of the caliber, provides the “programmed” information for the start, stop and return to zero functions of the chronograph. Sliding or cam chronographs are technically less complex, but no less reliable than column-wheel chronographs.

A seconds hand whose axis is not in the center of the dial. Most small seconds dials are located above the "6" on so-called "hunter" or "savonnette" watches, in which a 90° angle is formed by the crown, the center of the watch, and the axis of the seconds hand. Some movements are built in the so-called "Lépine" style: in these, the crown, the center of the dial and the axis of the small seconds hand (at "9 o'clock") all lie along the same line. Open pocket watches (i.e., Lépines with their crown at "12") have the small seconds at "6".

A phrase printed in lowercase on the dial of non- Swiss wristwatches enclosing a movement that was made in Switzerland. The phrase "SMv"it is found, for example, on plagiarized copies. Usually printed in lowercase letters, the phrase can mislead an unwary buyer into misinterpreting and mistakenly assuming that the second word of the phrase is "done".

Springs of various types are used in watch movements. In addition to the balance spring and mainspring, other common types of springs include bridge springs and friction springs.

Christian Huygens invented the flat balanced balance spring in 1675. The points of attachment of the spring to the balance staff (collet) and the balance spigot (pivot) are both in the same plane as the spring itself. Unlike Breguet overcoil balance springs, flat balance springs have the disadvantage that they do not develop absolutely concentrically as they expand and contract. This can have a negative effect on rate results. Modern mechanical movements usually have flat balance springs that have been given special deformation to counteract the above defects.

A thin cylinder used to fasten a ”closed”" bracelet to the horns. The conical pin on each end of the spring bar is pressed outward by a cylindrical spring inside the spring bar. To attach a bracelet to a watch case, a spring bar is first inserted through each end of the strap, then the spring ends of each spring bar are pressed inward, and the spring bar is inserted between the "horns" on the case. When the pressure is released, the sprung ends snap into place inside the holes that have been drilled in the horns to fit them.

This popular alloy is a combination of steel, nickel and chromium, with a mixture of molybdenum or tungsten. Stainless steel does not rust, is very resistant and non-magnetic, but is relatively difficult to work with. Wristwatches with stainless steel cases have become increasingly popular in recent years. This also applies to luxury wristwatches with stainless steel cases.

A device that stops the progress of the movement and / or second hand so that the movements can be set with an accuracy per second. To do this, the user pulls the crown outward at the instant when the second hand reaches "12". When he or she hears a time signal, the crown is pushed inward and the second hand (along with the other hands of the clock) resumes its movement.

An additional feature in a watch that allows the watch to audibly announce the time with greater or lesser precision. A distinction should be made between watches that always automatically strike the time and those that only repeat (ring) when activated by pressing a button or moving the position of a slide.

An escapement for small timepieces in which the teeth of the escape wheel widens as the distance from the center of the wheel increases. The enlarged teeth distribute the lift given to the escape wheel and the pallets with its two pallet jewels (rubies). In addition to the Swiss anchor escapement, there are also English and Glashütte anchor escapements.

Phrase, printed on the dial and / or imprinted in the movement, to identify the origin of a "Swiss wristwatch". According to the” Swiss Made Ordinance " of 27 May 1992, this phrase can only be used when the movement is Swiss and the assembly, coating and final quality checks have all been carried out in Switzerland. If a watch is to earn the right to carry the phrase " Swiss made” on the dial or movement, then at least 50% of the value of its components, excluding assembly costs, must derive from components that were manufactured in Switzerland. Non-Swiss manufacturers cannot use the phrase " Swiss made", but the assembly that has been carried out of Switzerland.