Tolerance Stack-Up
The cumulative effect of individual tolerances across a dimension chain in an assembly.
What it means on the floor
Tolerance stack-up analysis adds the tolerances along a chain of dimensions to predict the worst-case or statistical variation of a final gap or fit. Worst-case sums the extremes; the statistical (RSS) method root-sum-squares them for a more realistic spread.
Stack-up analysis catches assembly interference and fit problems on paper before tooling is cut.
Category: GD&T
Applying the term
Interpret Tolerance Stack-Up in the context of the drawing, governing standard, and customer requirement in front of you — the same word can carry different limits in design, quality, and production documents. Check whether a stated value is nominal, minimum, maximum, or reference-only, and whether it applies before forming, after forming, or after heat treatment.