ABSTRACT
Gages that check envelopes or boundaries are all designed on similar principles whether inspecting maximum material condition (MMC) size violations or virtual condition. Functional gages inspect for violations of the virtual condition boundary created by use of the MMC concept. Functional gages are made to the virtual condition of the features they check. These functional gages, as with the Go Gages that verify MMC, require tolerance that accepts no bad parts. The gaging policy in the United States states that, when designing gages, all of the tolerance goes against the part being gaged. The amount of tolerance has often been suggested as 5%-10% (5% of the tolerance on the part plus an additional optional 5% for wear allowance per American National Standards Institute (ANSI) B4.4, The Inspection of Workpieces Standard) of the part tolerance. The ultimate goal of any US gage is, most often, to accept as many good parts as possible, while never accepting a bad one.
