PIVOT

A pivot is the part located at both ends of, for example, a gear axle. For pivot diameters greater than 0.15 mm, we refer to a cylindrical pivot, with a straight bearing surface. For diameters of less than 0.15 mm, we refer to a conical pivot, with a conical bearing surface, which reinforces the small size of the pivot. In watchmaking, pivot bearings are generally in ruby. Cylindrical pivots have one jewel on each side, so two per axis, and conical pivots have two jewels on each side, so four per axis. The conical pivots of balance wheels are very often fitted with antichocs devices. A winding stem, for example, also has a pivot at its end. It is a cylindrical pivot that often pivots directly into the mainplate’s brass or german silver.