TOTW 29

There are a number of stainless steel alloys for watchmaking use. To machine the exterior components, in particular the middle, horns and the bezel, Girard-Perregaux has selected 316L steel. Its properties must withstand the conditions of use the changing demands of the environment: temperature variations, saline or acidic environment. It must also have characteristics such as corrosion resistance, hardness and impact absorption capacity, and also be able to undergo the desired finish level, such as polishing. Its hardness on the Vickers scale is 180 HV. By comparison, conventional steel has hardness of 160 Vickers. Furthermore, 316L steel is hypoallergenic.