Sprocket Bore Diameter 3/4 in For Chain Pitch 1/2 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 3/4 in Number of Teeth 15 Outside Diameter 2.65 in Pitch Diameter 2.405 in Bore Type Fixed Chain Number 40 Finish Black Oxide Hub Diameter 1 13/16 in Hub Projection 0.591 in Includes Set Screws Keyway Yes Keyway Depth 3/32 in Keyway Width 3/16 in Length through Bore 7/8 in Number of Set Screws 2