is the condition where the axis of all cross-sectional elements
of a surface of revolution are common to the axis of a datum
feature. A concentricity tolerance specifies a cylindrical
tolerance zone centered about the datum axis within which
the axis of the controlled feature can be specified only on
the RFS basic. Concentricity can also control variations in
the parallel orientation of
the controlled axis relative to the datum axis and the straightness
of the controlled axis.
as the concentricity deviation is equal to or less than the
specified concentricity tolerance, the part conforms to the
specification at the measured cross-section. The part,of course,
would have to be checked at all cross-sections in addition
to being rotated about the datum axis to determine if it acceptable.