Sprocket Bore Diameter 1 1/4 in For Chain Pitch 1 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 1/4 in Number of Teeth 11 Outside Diameter 4.01 in Pitch Diameter 3.55 in Bore Type Fixed Chain Number 80 Finish Black Oxide Hub Diameter 2 13/16 in Hub Projection 1.05 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