2. General concepts and principles of tolerancing

2.1 Fundamental principles

The precision of GPS language makes it possible to highlight the effects of imperfections in the manufactured part in the definition of the characteristics observed on the product through ISO GPS specifications. The nominal model of a part may have a cylindrical surface with a diameter, but with manufacturing imperfections, how can "this" diameter be characterized? There are multiple ways to define it, which will not have the same functional consequence on the final assembly! The intention is to use a GPS specification to define a single characteristic in order to limit customer-supplier disputes.

The dimensional, geometric, surface condition, and transition specifications are indicated on a technical document and form part of the...