DESIGN AND ENGINEERING


Pitch	Pitch is the distance between groove centers and is measured on the pulley pitch circle. On the belt, pitch is the distance between tooth centers and is measured on the pitch line of the belt.
Belt Diameter	Pulleys are designed to accept belts of a certain diameter. There is often a range of operational belt sizes for a given pulley; any overlap in the specified range and the pulley range will produce a match
Pitch Diameter	Pitch or datum diameter for a pulley is the diameter of the line of action. Typically it is at or near the center of the circular pulley groove.
Outside Diameter	Full diameter to outside of flanges.
Bore Diameter	Diameter of center hole for shaft mounting
Shaft Mounting Style	Set Screw / Keyway / Weld or Press-On / QD Hub / Taper Bushing / Clamp Hub

The pitch you choose will depend on the application’s load and speed. Timing belts must be run with timing pulleys of the same pitch. When running sets of pulleys the smaller pulley of the set is usually flanged. If three or more pulleys are in a drive, every other should be flanged. A pulley’s pitch diameter will always be greater than its outside diameter. Timing pulleys have evenly spaced axial grooves in order to make correct positive engagement with the mating teeth of the belt.