Form tolerance · ISO 1101

Flatness

Limits the gap between the highest and lowest points of a surface, with no datum involved.

In the shop

Distortion from clamping and residual stress usually matters more than the tool. Rough, relieve the clamping, then finish with a light pass on a sharp edge.

General shop guidance in our own words. The drawing and the standard it cites decide; verify on a sample part.

Related form tolerances

Circularity · Cylindricity · Straightness

Ask about your drawing

Tell the advisor the feature, the tolerance on the drawing and the material. It answers with machining choices, brand-neutral.

Sources

Definition written in our own words and checked against keyence.com. Symbol and term names follow ISO 1101; we do not reproduce standard text. See the full index.