Ring gages are used to evaluate the outside diameter of cylindrical workpieces. Ring gages are often used in pairs as go-no go gages. Rings with various forms, such as threads or splines are available.
Ring gages can be made with unilateral or bilateral tolerances. See Plug, Pin and Ring Gages.
Ring gages may be called setting rings or setting ring gage when a master ring gage is used to calibrate instruments designed to measure bore diameters.
“What Is the Point of a Setting Ring Gage? – Higher Precision.” Higher Precision, https://www.higherprecision.com/blog/what-is-the-point-of-a-setting-ring-gage. Accessed 26 Feb. 2021.