Sprocket Bore Diameter 1/2 in For Chain Pitch 1/2 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 in Number of Teeth 12 Outside Diameter 2.17 in Pitch Diameter 1.932 in Bore Type Plain Chain Number 40 Finish Black Oxide Hub Diameter 1 9/16 in Hub Projection 0.591 in Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 7/8 in Number of Set Screws 0 Set Screw Location Not Applicable