Tolerance Stack-up Analysis By James D. Meadows May 2026

Before you send a design for prototyping, review this checklist derived from the book:

Draw a loop starting from one side of the gap, traveling through each part’s relevant dimensions, and returning to the starting point. Label each vector with its nominal length and tolerance. Critical: Include geometric tolerances (flatness, perpendicularity, position) as equivalent linear tolerances. Meadows provides conversion tables for this. tolerance stack-up analysis by james d. meadows

In mechanical design, specifying individual part tolerances is insufficient to guarantee a working assembly. Parts that are 100% within their specified tolerances can still fail to assemble or function correctly due to the cumulative effect of variations. This cumulative effect is known as tolerance stack-up. Before you send a design for prototyping, review

James D. Meadows is a leading authority in the field of GD&T and tolerance analysis. Unlike simplistic "worst-case" arithmetic methods, Meadows advocates for a systematic, geometry-based approach that respects the rules of ASME Y14.5M-1994 (and later revisions). His methodology focuses on converting drawing tolerances into consistent boundary conditions (Inner and Outer Boundaries) to perform accurate 1D stack-up analyses. Draw a loop starting from one side of

To understand Meadows’ analysis techniques, you must first understand his three core tenets.