A thread gage is used to measure the pitch of a screw thread. This can be done for male and female thread gages and allows for the user to identify the profile of a thread and categorize the thread by pitch and shape.

For male threads, measure the outside diameter. For female threads, measure the inside. Thread pitches can differ between metric threads and standard thread sizes.

Thread gages can be checked by using an adjustable thread ring and measuring the thread gage at the required pitch diameter. This works for both metric and standard gages.

Thread plug gages check tolerances of threaded parts according to pre-determined specifications. These gages check mating parts and provide a level of quality control for metric and standard gages. Generally thread plug gages have Go & No GO tolerance indicators.

A thread gage helps identify the pitch diameter of a threaded object. Thread gages can be custom made to check the thread pitch for metric threads or standard sizes.