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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.

Origin of pitch surface

First recorded in 1885–90
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for pitch surface

Historical Examples of pitch surface