On interpreting statistical tolerancing

Abstract

The new ASME Y14.5M standard will provide, for the first time, a symbol to identify in a drawing those dimensional tolerances that should be interpreted statistically. It will stipulate further that the features so identified shall be produced with statistical process controls. As it stands, the explanation is incomplete. In this paper, the authors describe three interpretations defined by the first two moments, the process capability indices, or bounding cumulative distribution functions.