Ring gages are used for go/no-go assessment compared to the specified dimensional tolerances or attributes of pins, shafts, or threaded studs. Ring gages are used for comparative gaging as well as for the checking, calibrating, or setting of gages or other standards. Individual ring gages, or ring gage sets, are made for a variety of tolerance grades in metric and English dimensions for master, setting, or working applications. Rings are available in plain (smooth, unthreaded), threaded, cylindrical, and tapered forms to go, no-go, or nominal tolerances. 

Types of Ring Gages

There are three main types of ring gages:

• go ring gages
• no-go ring gages
• master or setting ring gages

Go ring gages provide a precision tool for production comparative gaging based on a fixed limit. Go gages consist of a fixed limit gage with a gaging limit based on the plus or minus tolerances of the inspected part. A go ring gage's dimensions are based on the maximum OD tolerance of the round bar or part being gaged. A go plug gage's dimensions are based on the minimum ID tolerance of the hole or part being gaged. The go plug (ID) gage should be specified to a plus gagemakers' tolerance from the minimum part tolerance. The go ring (OD) gage should be specified to a minus gagemakers' tolerance from the maximum part tolerance.

No-go, or not-go, gages provide a precision tool for production comparative gaging based on a fixed limit. No-go gages consist of a fixed limit gage with a gaging limit based on the minimum or maximum tolerances of the inspected part. A no-go ring gage's dimensions are based on the minimum OD tolerance of the round bar or part being gaged. The no-go ring (OD) gage should be specified to a plus gagemakers' tolerance from the minimum part tolerance.

Master and setting ring gages include gage blocks, master or setting discs, and setting rings. They are types of master gages used to calibrate or set micrometers, comparators, or other gaging systems. Working gages are used in the shop for dimensional inspection and periodically checked against a master gage.

Related Information

CR4 Community—Material Suitable for Ring Gages

Image credit:

Wiseman Threading Tools Ltd.