ASME Y14.5 : Dimensioning and Tolerancing

A similar perfect feature(s) counterpart of smallest size that can be contracted about an external feature(s) or of largest size that can be expanded within an internal feature(s) so that it coincides with the surface(s) at the highest points. This envelope is on or outside the material. There are two types of AMEs, as described below. (a) related AME: a similar perfect feature(s) counterpart expanded within an internal feature(s) or contracted about an external feature(s) while constrained in orientation, in location, or in both orientation and location to the applicable datum(s). (b) unrelated AME: a similar perfectfeature(s) counterpart expanded within an internal feature(s) or contracted about an external feature(s), and not constrained to any datum(s).

See Also:

Feature, Datum