Form Tolerance and Location Tolerance (Profile Tolerance of Line / Profile Tolerance of Plane)

The profile tolerances of lines and planes are also used in specifying location tolerance. Specifications are indicated in the feature control frame the same way for form tolerance and location tolerance.

Profile tolerance of line

Profile tolerance of line

The profile of the line requirement indicates whether the curvature of a designed part is made to its design. The value indicates any distortion in the profile line (line element that appears on the cross-section of a surface). The cross-section line cutting across the specified curvature must be within the tolerance zone.

Sample indication
Profile tolerance of line
Explanation of drawings
The target profile on any cross-section parallel to the projection plane must be between the two envelopes created by a circle with a diameter of 0.03 mm and a center on the line having a theoretically exact profile.

Profile tolerance of plane

Profile tolerance of plane

The profile of the plane requirement indicates whether the curvature (surface) of a designed part is made to its design.
Unlike the profile tolerance of a line, the profile tolerance of the plane involves the entire specified curvature.

Sample indication
Profile tolerance of plane
Explanation of drawings
The target plane must be between two envelope planes created by a sphere with a diameter of 0.1 mm and a center on the plane having a theoretically exact profile.

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