Timing Belt Pulleys Bore Diameter 3/16 in For Belt Series XL For Belt Width 3/8 in For Use With 3/8 in Wide Belts Material Aluminum Maximum Bore Diameter Not Applicable Number of Teeth 10 Outside Diameter 0.875 in Pitch 0.2 in Pitch Diameter 0.637 in Bore Type Fixed Face Width 0.563 in Features Built for High-Torque Low-Speed Applications Outperforms Industry Standards Superb Flexibility Finish Anodized For Belt Trade Size XL Hub Diameter 7/16 in Hub Projection 1/4 in