Gearbelt Pulley Bore Diameter 1/2 in For Belt Series SilentSync For Belt Width 64 mm For Use With SilentSync Purple Belts Material Ductile Iron Number of Teeth 72 Outside Diameter 181.98 mm Pitch 8 mm Pitch Diameter 183.35 mm Bore Type Plain Face Width 65 mm Features Self-Tracking Design For Belt Trade Size P-72S Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 65 mm Material Fabrication Machined Maximum Operating Temperature 200 Degrees F