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 15 Outside Diameter 5.3 in Pitch Diameter 4.81 in Bore Type Fixed Chain Number 80 Finish Black Oxide Hub Diameter 3 13/16 in Hub Projection 0.925 in Includes Set Screws Keyway Yes Keyway Depth 1/8 in Keyway Width 1/4 in Length through Bore 1 1/2 in Number of Set Screws 2