GDT Symbols

For each geometric characteristic, sketch its associated ASME Y14.5 symbol and label the type of tolerance.

Hint
Recall any symbols you may have seen in a feature control frame on a drawing.
Hint 2
There are five types of tolerances: form, orientation, location, runout, and location of derived median points.
There are 14 geometric tolerancing characteristics, with relatively straightforward symbols based on their description. The characteristic symbols are placed in the first compartment of a feature control frame and define the type of tolerance that is applied to the feature.
There are five types of tolerances. Form tolerances control the features’ “shape” and are commonly used as a refinement of size. Orientation tolerances control the features’ “tilt” and are always associated with basic angle dimensions. Location tolerances control location (center points, axes, median planes, surfaces, etc.) and are always associated with basic linear dimensions. Runout tolerances control surface co-axiality. Finally, location of derived median points tolerances locate the derived median points of a feature. Keep in mind that position, profile, runout, and median points are a subset of location tolerance types.