Roller Chain Sprocket Bore Diameter 5/8 in For Chain Pitch 3/8 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 5/8 in Number of Teeth 40 Outside Diameter 4.99 in Pitch Diameter 4.78 in Bore Type Fixed Chain Number 35 Finish Black Oxide Hub Diameter 2 1/4 in Hub Projection 0.832 in Includes Set Screws Keyway Yes Keyway Width 3/16 in Length through Bore 1 in Number of Set Screws 2