Form Tolerances

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.

Roundness or Circularity

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
Straightness is a form tolerance in GD&T that controls how much a feature or an element of a surface can deviate from a perfectly straight line. Unlike flatness, which applies to a surface, straightness applies to either individual line elements on a surface or to the axis of a cylindrical feature. Straightness applies in one...

Flatness

Flatness
Flatness is a form tolerance in GD&T that controls how much a surface can deviate from being perfectly flat. It ensures that the surface does not have excessive waviness, warping, or unevenness, which is critical in applications where a component must mate properly with another part. Symbol for Flatness Flatness Symbol: ▱ (parallelogram) Flatness Tolerance...
Roundness or Circularity

Roundness or Circularity

Circularity is used to control how circular a feature, like a hole or a cylindrical surface, must be....
Straightness

Straightness

Straightness is a form tolerance in GD&T that controls how much a feature or an element of a surface...
Flatness

Flatness

Flatness is a form tolerance in GD&T that controls how much a surface can deviate from being perfectly...