Sprocket Bore Diameter 5/8 in For Chain Pitch 5/8 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 5/16 in Number of Teeth 13 Outside Diameter 2.91 in Pitch Diameter 2.612 in Bore Type Plain Chain Number 50 Finish Black Oxide For Pitch Type Single Pitch Hub Diameter 1 7/8 in Hub Projection 0.657 in Includes Set Screws Keyway Yes Keyway Depth 3/32 in Keyway Width 3/16 in Length through Bore 1 in Material Grade 1045