Form tolerances limit the amount of deviation from a perfect geometric form, such as a line, circle, plane or cylinder. They control only features themselves, and not in relation to any other feature.
Form Tolerances
Roundness or Circularity
Circularity is used to control how circular a feature, like a hole or a cylindrical surface, must be. It limits deviations from a perfect circle. Circularity is inspected only as individual circle elements within a single plane at a time. It does not limit the location or orientation of the circular element relative to any...
Straightness
Straightness applies in one direction only. I applies in the direction where the controlled area is represented as a straight line. Straightness can be applied to surface elements or a derived median line. In the example below, the part is straight along its length, except for the portion with the discontinuity. Straightness is in one...
Roundness or Circularity
Circularity is used to control how circular a feature, like a hole or a cylindrical surface, must be....
Straightness
Straightness applies in one direction only. I applies in the direction where the controlled area is...