gage pins

PRECISION plug gage measuring

Plug Gage Measuring is the art of using pre-sized precision metal plugs to determine the acceptability of diameters of drilled or machined holes. The difference between any class of gage is not the wear or life span of the gage, it’s the tolerance which is allowed in the manufacturing process of the gage.

GO/NOGO Measurement is a popular method to measure diameters. A GO gage is used to check the lower limit of a hole. A NOGO gage is used to check the upper limit of a hole. If the GO gage enters the hole and the NOGO gage is unable to enter, the design specifications of the hole have been met.

Gages are Carbon Chrome Alloy Steel (grade 52100 bearing quality steel) and heat treated to a 60-62 Rockwell C hardness.

At we offer several different manufacturers, classes (tolerances), and black oxide or polished finishes of Gage Pins. Gage Pins are perfect for precision GO/NOGO measuring of hole sizes and depths, checking hole location and distance, and setting micrometers. 

All gages are uniformly 2″ long with ground ends, allowing you to use both ends for increased gage life. 


some of our most popular gage pin sets...