Tooling/Vise Held Mainspring Winder

This tool is used to wind the mainspring of a watch so that it can be safely inserted into the barrel.

A mainspring winder, with crank, that is meant to be held in a vise

This style of mainspring winder is no longer widely available for purchase. The example above features three interchangeable drums to accommodate barrels of various diameters. The arbor is not interchangeable.

[edit] How to Use the Mainspring Winder

A close-up of the interchangeable drums in which the mainspring can be wound

To use the mainspring winder, the base of tool must first be clamped tightly in a vise. Affix the inner coil of the mainspring to be wound onto the hooked arbor of the tool. Wind the crank until the mainspring has been wound entirely into the drum. Place the drum, with wound mainspring, as deeply into the barrel as it will go. Pull the drum backwards, allowing the bottom of the drum (which is mobile) to push the mainspring into the barrel.