Pin gauge is a measuring tool in the form of a precision-sized pin. The main function of pin gauge is for inspection or checking the inner diameter of a workpiece.

Pin gauges are commonly sold in sets or individually. A set of pin gauges is available in various sizes with very small differences. Product variations of pin gauges include: master pin gauge, ET series, EP series, ECP series, EX series, EH series, EM+ series, EM- series, EG series, and many more.