GLUCYDUR

Glucydur is a Alloy special — mainly composed of Beryllium, Copper and iron — widely used in watchmaking for the manufacture of balances and certain components of the Movement. It is particularly valued for its high dimensional stability, its Hardness high, its low sensitivity to variations in Temperature and its non-magnetic character. A Balance in Glucydur therefore retains its diameter and its Inertia despite thermal changes, which directly contributes to timekeeping accuracy; its Hardness also makes it resistant to wear and easy to poise with precision. Combined with a Hairspring (balance spring) self-compensating (in Nivarox or in Silicon), it forms an oscillator that is little sensitive to Temperature and magnetism, a standard of quality mechanical horology since the mid-20th century. Glucydur illustrates the contribution of modern metallurgy to chronometry: the choice of alloys with controlled properties made it possible to move away from old bimetallic Balances and to durably improve the stability of watches.

Glucydur was developed in the early 20th century, at the same time as Nivarox, as part of research conducted by the Swiss watchmaking industry to move away from bimetallic Balances (Steel-Brass), which were more sensitive to shocks and position variations. Its high Hardness (about 400 HB on the Brinell scale) allows precise machining of the Balance arms and Felloe (rim base) as well as fine Poising by drilling or Screw, without deformation or creep over Time. Chemically inert, it also resists corrosion and oxidation. The term Glucydur, now part of everyday watchmaking vocabulary, remains a precise commercial name, to be distinguished from other competing Non-magnetic Alloys developed later for the same purpose.