Determine if lead nuts, screw collars, and other parts with internal Acme threads are within tolerance. These gauges are attached to a handle to help you quickly thread or unthread them. All are precisely manufactured to tight tolerances. Instead of replacing the whole tool when a gauge wears down, you can insert a new gauge (not included) into the handle.

A part is within tolerance if it’s easy to thread the go gauge into the part but difficult to thread the no-go gauge more than two turns.

Go gauges check the minimum internal thread size. No-go gauges check the maximum internal thread size.

Thread fit designates the tightness or looseness of mating threads. 2G is standard for Acme threads.

For technical drawings and 3-D models, click on a part number.