Vtg Cannon Pinion Tightener Movements watchmaker Clock Repair Machinist Tool

watchmaker's cannon pinion tightener, specifically similar to vintage models used for repairing watch movements.Function: It is designed to tighten the cannon pinion in a watch movement, which often becomes loose over time.Mechanism: The tool typically utilizes a tapered screw to press two jaws together, applying pressure to the pinion to shrink its opening.Usage: A support pin or needle is usually inserted into the pinion before tightening to prevent it from being crushed during the process..  got these from an old watchmaker clock repair shop... have a bunch of specialty tools were listing...