LEAST-COST TOLERANCES—I

Abstract

This paper presents a method of assigning tolerances to components so that (a) assemblies composed of the components meet specified functional requirements and (b) the cost of manufacturing all the components to their respective tolerance is minimised. Methods of obtaining tolerance equations from functional equations are briefly reviewed; the “method of extremes” is explained in detail. A relationship between cost and tolerance is derived, based upon published data. A method of assigning least-cost tolerances to a single tolerance equation is then developed.