Geometric Dimensioning and Tolerancing (GD&T)
Geometric Dimensioning and Tolerancing (GD&T) is a symbolic language used in engineering and manufacturing to define the allowable variation in form, orientation, location, and size of features on a part. It provides a precise and standardized way to communicate design intent and functional requirements, replacing traditional plus/minus tolerancing with more comprehensive geometric controls. This system ensures parts fit and function correctly in assemblies, improving quality and reducing manufacturing costs.
Developers in mechanical engineering, CAD/CAM, or manufacturing software should learn GD&T when designing or analyzing parts that require precise fit, interchangeability, or functional performance, such as in automotive, aerospace, or medical device industries. It is used to specify tolerances for features like holes, surfaces, and axes, enabling better communication between design and production teams and reducing ambiguity compared to plus/minus tolerancing.