Roller Chain Sprocket Bore Diameter 3/8 in For Chain Pitch 1/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 3/8 in Number of Teeth 13 Outside Diameter 1.167 in Pitch Diameter 1.044 in Bore Type Fixed Chain Number 25 Finish Black Oxide Hub Diameter 3/4 in Hub Projection 0.39 in Includes Set Screws Keyway No Keyway Depth Not Applicable Keyway Width Not Applicable Length through Bore 1/2 in Number of Set Screws 2