Serial Lookup

Choose a manufacturer, enter the serial number, or search by trade name and private label.

Sign In Notifications
Pocket Watch Mainsprings

Pocket Watch Mainspring Part Numbers, Sizes, & Types

The mainspring provides power to the mechanics of the watch. When a mainspring breaks or no longer offers enough energy for precise timekeeping, a replacement will be required. Measure the dimensions of the old mainspring using a micrometer, and use the chart below to find proper replacement for any American movement. Note: Using proper tools for mainspring installation is highly advised.

Professional Installation Strongly Recommended

Mainspring replacement requires specialized tools and expertise. Improper installation can damage your watch or cause injury. Consider having a professional watchmaker perform this repair.

 Show All Mainsprings

No mainspring data is available for this selection.