Roller Chain Sprocket Bore Diameter 1 1/4 in For Chain Pitch 5/8 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 1/4 in Number of Teeth 45 Outside Diameter 9.31 in Pitch Diameter 8.96 in Bore Type Fixed Chain Number 50 Finish Black Oxide Hub Diameter 3 3/4 in Hub Projection 0.907 in Includes Set Screws Keyway Yes Keyway Width 1/4 in Length through Bore 1 1/4 in Number of Set Screws 2