Sprocket Bore Diameter 1 1/4 in For Chain Pitch 1 1/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 1/4 in Number of Teeth 13 Outside Diameter 5.82 in Pitch Diameter 5.82 in Bore Type Fixed Chain Number 100 Finish Black Oxide Hub Diameter 3 7/8 in Hub Projection 0.933 in Includes Set Screws Keyway Yes Keyway Depth 1/8 in Keyway Width 1/4 in Length through Bore 1 5/8 in Number of Set Screws 2