Circularity (roundness)

Limits how far a cross-section may deviate from a perfect circle.

In the shop

In turning, out-of-round comes from clamping pressure on thin walls, spindle play and tool deflection. Soft jaws spread the load; finish with a sharp insert and a light cut.

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

Related form tolerances

Cylindricity · Flatness · 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.