====== Glucydur ======
**Glucydur** is an alloy of copper and 2-3% beryllium. This alloy has particularly good mechanical properties. It is non-magnetic and non-oxidizing and at normal temperatures has only a very small expansion. Therefore, it is preferred for monometallic [[balance wheel]]s used in watch [[movement]]s.

The word is a combination of the French words //glucinium// and //dur// (French = hard).


{{tag>Terms Watch_materials}}