What is a critical factor to consider when evaluating tolerance stack-up?

When evaluating tolerance stack-up, considering the number of parts being assembled is critical because it directly impacts how variations in individual component tolerances accumulate and affect the overall assembly. Each part in an assembly has its own tolerances, and when several parts are combined, the cumulative effect of these variations can lead to misalignment or deviations in the final product. If multiple parts are involved, the risk of significant stack-up increases because each added component contributes its own tolerance range to the overall assembly.

Understanding this relationship allows engineers and toolmakers to design assemblies that account for potential variations from each individual part, ensuring that the final product functions as intended without issues arising from inaccuracies in fit or alignment. Therefore, managing the number of parts effectively helps to achieve desired precision and functionality in the finished assembly.