1 month ago
Finer than a human hair, the blue Parachrom hairspring is a key component of Calibre 3131, powering the Milgauss and contributing to its magnetic resistance. Manufacturing begins with the fusion of niobium and zirconium under vacuum at approximately 2,400° C. The resulting alloy rod is transformed during a series of operations to obtain a 3km-long wire with a diameter of 0.1mm. This wire is then flattened into an even finer ribbon, approximately 50 microns thick, before being cut into 20cm-long segments, each of which is coiled. The hairspring’s shape is fixed using a high-temperature thermal vacuum treatment. The hairspring is then given a Rolex overcoil, which ensures its regularity in any position.