Roller Chain Sprocket Bore Diameter 3/4 in For Chain Pitch 3/4 in For Number of Strands Single Hub Type No Hub Material Steel Maximum Bore Diameter 1 3/8 in Number of Teeth 12 Outside Diameter 3.25 in Pitch Diameter 2.898 in Bore Type Plain Chain Number 60 Finish Black Oxide Hub Diameter Not Applicable Hub Projection Not Applicable Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 7/16 in Number of Set Screws 0