Timing Belt Pulleys Bore Diameter 3/4 in For Belt Series H For Belt Width 2 in For Use With 2 in Wide Belts Material Steel Maximum Bore Diameter Not Applicable Number of Teeth 18 Outside Diameter 3.1 in Pitch 0.5 in Pitch Diameter 2.865 in Bore Type Plain Face Width 2.344 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Black Oxide For Belt Trade Size H Hub Diameter 2 1/4 in Hub Projection 11/16 in