Roller Chain Sprocket Bore Diameter 16 mm For Chain Pitch 5/8 in For Number of Strands Single Hub Type No Hub Material Steel Maximum Bore Diameter 51 mm Number of Teeth 20 Outside Diameter 4.4 in Pitch Diameter 101.48 mm Bore Type Plain Chain Number 10B Finish Black Oxide Hub Diameter Not Applicable Hub Projection Not Applicable Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 3/8 in Number of Set Screws 0 Set Screw Location Not Applicable