Pitch diameter - in metric units (gears)


Is a predefined diametral position on the gear, where the circular tooth thickness, pressure angle and helix angles are defined. The standard pitch diameter is a basic dimension and cannot be measured, but is a location where other measurements are made. Its value is based on the number of teeth, the normal module (or normal diametral pitch), and the helix angle.

Related formulas


dPitch diameter (in metric units) (cm)
NNumber of teeth (dimensionless)
mnNormal module (or normal diametral pitch) (cm)
ψHelix angle (dimensionless)