pitch cylinder

noun Machinery.

1. See under pitch surface.

noun

1. (in a gear or rack) an imaginary surface forming a plane (pitch plane), a cylinder (pitch cylinder), or a cone or frustrum (pitch cone) that moves tangentially to a similar surface in a meshing gear so that both surfaces travel at the same speed.

noun

1. an imaginary cylinder passing through, and coaxial with, the threads of a screw so that its intersection with opposite flanks of any groove is equal to half the thread pitch