Geometric Dimensioning and Tolerancing

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Geometric dimensioning and tolerancing is a symbolic language used on engineering drawings and computer generated three-dimensional solid models for explicitly describing nominal geometry and its allowable variation. Geometric dimensioning and tolerancing is used to define the nominal geometry of parts and assemblies, to define the allowable variation in form and possibly size of individual features, and to define the allowable variation between features. There are several standards available worldwide that describe the symbols and define the rules used in GD&T. One such standard is American Society of Mechanical Engineers Y14.5M-1994. This article is based on that standard, but other standards, such as those from the International Organization for Standardization, may vary slightly.