Glucydur is the trade name of a metal

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductilit ...

with a low

coefficient of thermal expansion Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions. Temperature is a monotonic function of the average molecular kineti ...

, used for making

balance wheel A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a ...

s and other parts of

mechanical watch A mechanical watch is a watch that uses a clockwork mechanism to measure the passage of time, as opposed to quartz watches which function using the vibration modes of a piezoelectric quartz tuning fork, or radio watches, which are quartz wat ...

es. Glucydur is a beryllium bronze; an alloy of

beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form m ...

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

and

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

. In addition to its low coefficient of thermal expansion, its hardness (400 Brinell), nonmagnetizability, and resistance to deformation and damage make it suited for making precision parts that must have high dimensional stability. Glucydur is also resistant to

corrosion Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engi ...

; it is rather inert chemically. Glucydur was developed about the same time as another non-magnetic material,

Nivarox Nivarox, also known as Nivarox - FAR SA is a Swiss company formed by a merger in 1984 between Nivarox SA and Fabriques d' Assortiments Réunis (FAR). It is currently owned by the Swatch Group. Nivarox is also the trade name of the metallic alloy fro ...

References

* . Technical article on construction of watch balance wheels, on watch repair website. Copper alloys Ferrous alloys Beryllium alloys Timekeeping components Low thermal expansion materials {{alloy-stub