Sprocket Bore Diameter 1 3/16 in For Chain Pitch 1/2 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 3/16 in Number of Teeth 30 Outside Diameter 5.06 in Pitch Diameter 4.783 in Bore Type Fixed Chain Number 40 Finish Black Oxide Hub Diameter 3 3/4 in Hub Projection 0.716 in Includes Set Screws Keyway Yes Keyway Depth 1/8 in Keyway Width 1/4 in Length through Bore 1 in Number of Set Screws 2