Pin Punch Set

Specification

Technical parameters

Overview

A pin punch has a flat, parallel tip of a specific diameter, unlike a centre punch which has a point. In horology they are used to drive out the pins that hold bracelet links, case springs and some band attachments, and to free arbors and pins that have corroded in place.

The diameter is the specification that matters — a punch slightly narrower than the pin is correct, because a wider punch will burr the end of the pin and jam it harder. Sets are sized in tenths of a millimetre for that reason.

Support is the other half of the technique. Whatever you punch must be backed by a bench block with a hole, so the pin has somewhere to go. Punching against a soft or unsupported surface just bends the part.

What matters about it

• Parallel flat tip drives pins without burring them
• Sized in fine increments to match pin diameters
• Used with a bench block so pins have somewhere to go
• Handles bracelet work as well as movement work
• Tips can be re-squared rather than replaced

Practical notes

• Measure the pin, then choose the largest punch that is still slightly narrower.
• Support the work on a block with a relief hole directly under the pin.
• A pin that will not move usually needs penetrating fluid and time, not a bigger hammer.
• Dress a mushroomed punch tip before the next use.

Compatible with