Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describe nominal geometry and its allowable variation. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part. GD&T is used to define the nominal (theoretically perfect) geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features.
Types of Tolerance:
Three basic tolerances that occur most often on working drawings are: limit dimensions, unilateral, and bilateral tolerances. Three basic tolerances that occur most often on working drawings are: limit dimensions, unilateral, and bilateral tolerances.
At Canter Cadd we cover the below mentioned topics under GD & T
● Introduction to Geometric Dimensioning and Tolerance
● Dimensions and drawings
● Tolerance dimensioning
● Ways of expressing tolerance
● IT Grades
● Introduction to ASME Y 14.5-1994
● GD & T Rules
● Maximum Material condition of a feature of size
● Least Material condition of a feature of size