Roller Chain Sprocket Bore Diameter 1 3/8 in For Chain Pitch 1 1/4 in For Number of Strands Single Hub Type No Hub Material Steel Maximum Bore Diameter 3 5/16 in Number of Teeth 28 Outside Diameter 11.84 in Pitch Diameter 11.164 in Bore Type Plain Chain Number 100 Finish Black Oxide Hub Diameter Not Applicable Hub Projection Not Applicable Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 11/16 in Number of Set Screws 0