Diametral pitch Meaning, Definition & Usage

Definitions
  1. (Gearing), the distance which bears the same relation to the pitch proper, or circular pitch, that the diameter of a circle bears to its circumference; it is sometimes described by the number expressing the quotient obtained by dividing the number of teeth in a wheel by the diameter of its pitch circle in inches; as, 4 pitch, 8 pitch, etc.

Webster 1913