Definition: The condition in which the axis of the unrelated actual mating envelope (AME) or axis of the unrelated minimum material envelope, as applicable, of one or more surfaces of revolution is coincident with a datum axis or another feature axis.

Citation: ASME Y14.5 : Dimensioning and Tolerancing

See Also:

Actual Mating Envelope, Actual Minimum Material Envelope, Datum Axis, Feature Axis