7. Analysis of manufacturing dimensions and tolerances

First, let's look at the case of unidirectional dimensions. The dimensions shown on the definition drawings are not necessarily executed directly in manufacturing. The functional dimensions required by the drawing, and which must absolutely be respected, are transferred into resultant dimensions which are affected by the tolerances of all the component dimensions of a manufacturing dimension chain. Since the resulting tolerances are the sum of the component tolerances, it is clear that compliance with functional tolerances requires a reduction in the component tolerances, which are generally the result of manufacturing operations with given tolerances. To illustrate this principle of tolerance transfer on a simple example, figure 17...