Roller Chain Sprocket Bore Diameter 3/4 in For Chain Pitch 1/2 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 3/4 in Number of Teeth 13 Outside Diameter 2.33 in Pitch Diameter 2.089 in Bore Type Fixed Chain Number 41 Finish Black Oxide Hub Diameter 1 9/16 in Hub Projection 0.648 in Includes Set Screws Keyway Yes Keyway Width 3/16 in Length through Bore 7/8 in Number of Set Screws 2