is the condition of a surface of revolution in which all points
on the surface are equidistant from the axis. It differs from
roundness in that it simultaneously controls the roundness
of circlar line elements and the straightness and parallelisum
of the straight line elements of the surface.
The Cylindricity symbol is used to describe an object
conforms to a cylinder axis. a cylindrical feature to ensure
that it is round enough and straight enough along its axis.