P = Pitch is the distance between the axes of two adjacent teeth in spite of whether these teeth are on the pulley or the belt provided and measurement is taken on the circumference of pitch line
Z = teeth Number
Dp = P . Z
π
The pitch diameter is obtained from fomula
De = External diameter of pulley De= Dp-Hf
Dm = Hub diameter
d = Bore diameter
F = Tooth width
L = Total length including hubs

Example of Mark

Type of Basic Structure of Timing Pulleys

Design Hose Power (Hose Power Service Factor)

Check acailabe sizes