Geometric Dimensioning and Tolerancing
Geometric Dimensioning and Tolerancing (GD&T) is a symbolic language used on engineering drawings and computer-generated three-dimensional solid models to explicitly describe nominal geometry and its allowable variation. It defines the allowable deviation in form, orientation, location, and runout of features on a part, ensuring that parts function properly when assembled. GD&T is a critical standard in manufacturing and mechanical engineering for communicating design intent and quality requirements.
Developers in mechanical engineering, CAD/CAM, robotics, or manufacturing software should learn GD&T to create precise 3D models, automate quality control, or develop simulation tools. It is essential for ensuring interoperability in complex assemblies, reducing manufacturing costs by allowing functional tolerances, and complying with industry standards like ASME Y14.5 or ISO 1101. Use cases include designing automotive components, aerospace parts, or medical devices where tight tolerances are critical.