Ring gauge

A ring gauge, or ring gage, is a cylindrical ring of a thermally stable material, often steel, whose inside diameter is finished to gauge tolerance and is used for checking the external diameter of a cylindrical object.

Individual ring gauges or ring gauge sets are made to variety of tolerance grades in metric and English dimensions for master, setting, or working applications.

No-go or not-go gauges provide a precision tool for production comparative gauging based on a fixed limit.

Similar to gage blocks, ring gauges are sold under different accuracy grades.

The higher the grade, the lower the allowable variance from the nominal diameter.

"Go" spline ring gage