Geometric Dimensioning and Tolerancing (GD&T) Practice Exam

The Datum System is essential in Geometric Dimensioning and Tolerancing because it establishes a reference framework for measurements and inspections. When a datum is defined on a part, it allows an inspector to understand precisely how features should be located relative to one another during inspection. This systematic approach means that the inspector can accurately assess whether the part meets design specifications by knowing the exact reference points from which all measurements should be taken.

By specifying datums, designers convey critical information about the intended relationships between features, ensuring consistency and accuracy in the measurement process. This clarity in defining how dimensions are to be inspected is crucial for maintaining quality and ensuring that parts fit and function as intended.