Total Runout

Controls variation of an entire surface as the part rotates 360 degrees about a datum axis.

⌰

0.05

Total runout controls the complete surface variation of a rotating feature relative to a datum axis.

It combines effects from circularity, cylindricity, straightness, taper, and coaxial relationship into one functional rotating-surface requirement.

Use it for shafts, bearing journals, gears, spindles, and other rotating surfaces where full-length wobble or taper would damage function.

It is stricter than circular runout because the entire surface must remain acceptable as the indicator sweeps along the axis.

Full Shaft Surface Swept During Rotation

Total runout extends the runout check along the whole surface rather than checking one cross-section at a time.

\u2197

0.03

A 3D zone around the full controlled surface while the datum axis is held fixed during rotation.

Constrain the datum axis in centers, V-blocks, or a spindle, rotate the part, and sweep an indicator along the controlled surface.

The total indicator variation across the complete surface must stay within the stated tolerance.

A shaft journal has total runout 0.05 mm to datum A. The swept indicator ranges from -0.018 mm to +0.024 mm.

Indicator spread

0.024 - (-0.018) = 0.042 mm

Use the worst reading from the full sweep while the part rotates.

Compare

0.042 <= 0.05

The full surface stays inside the total runout limit.

Coverage

Full length

Unlike circular runout, this includes axial surface variation.

The journal passes total runout relative to datum A.

Control	Coverage	Datum	Common Use
Circular runout	One cross-section	Axis	Local wobble
Total runout	Full surface	Axis	Full rotating surface
Cylindricity	Full cylinder	No	Form only

Total runout is always relative to a datum axis and does not use MMC or LMC bonus tolerance.

Circular runout checks sections; total runout checks the whole controlled surface.