PIN VICE (or hand-chuck)
WHAT ARE PIN VICES USED FOR?
In watchmaking, pin vices (also called hand-operated chucks) designate a family of hand-held work-holding tools intended to grip a small cylindrical component in order to present it to the cutting or finishing tool. Unlike a lathe chuck or a drill chuck, which is fastened to a machine and driven by a motor, the pin vice is held directly by the operator; it provides a precise, repeatable grip for operations conducted manually at the workbench.
In its most common form, the pin vice consists of a cylindrical body of steel or brass, extended on one side by a knurled handle that facilitates grip and rotation, and provided at the opposite end with a clamping system. Clamping is generally achieved by a split collet, compressed around the component by tightening a threaded ring. To adapt to the wide range of diameters encountered in the watch movement — from the finest wires to stems and screw bodies — a single pin vice can accept a set of interchangeable collets, each calibrated to a specific diameter.
The watchmaker uses pin vices in a wide variety of operations. Filing, polishing, burnishing and smoothing of cylindrical components benefit from a firm, strictly axial support: the component, held in the collet, is set in rotation by the simple movement of the operator’s fingers, while the other hand guides the burnisher, the cabron (buff stick) or an abrasive paper. This combination of regular manual rotation and controlled tool contact is particularly well suited to the finishing of arbors, stems and screws, where cylindricity and surface finish directly govern the quality of the running. The pin vice is also used for marking, visual inspection or simply holding a component during an examination under a loupe.
Several variants complete the watchmaker’s workbench: short pin vices known as “pocket” types for quick interventions, or multi-collet pin vices that allow several components to be mounted in parallel. In these capacities, pin vices rank among the most versatile work-holding tools on the watchmaker’s bench: modest in appearance, they in fact contribute to the vast majority of finishing and fitting (ajustage) operations on rotating components.