PLAIN PLUG AND RING GAUGES (CLASS Z, Y, X, XX)
How to Determine and Select the Proper Tolerance for Your Gauging Application
The normal rule of practice requires 10 % of product tolerance to divided between the ‘GO and NOGO” gauges. For plug gauges, a plus tolerance is applied to the GO member and a minus tolerance to NOGO member. Ring gauges receive reverse tolerance direction so that the GO member is a minus and the NOGO is plus tolerance. Applying this result practice results in gauge tolerance always being included in the part tolerance by up to 10%. This results in the possibility that 10% of good product could fail inspection that no bad product would ever pass.
Cylindrical Plain Plug/Ring Tolerance Classes (ASME/ANSI B89.1.6 & B89.1.5)
Proper Care Usage of Gauges
- Parts Dimensions to be gauged should be free of burrs to prevent gauging interference.
- Gauges should be turned or pushed slowly and gently. Forcing gauges will result in faulty gauging and possibility of damaging both the gauge and the part.