Roller Chain Sprocket Bore Diameter 1/4 in For Chain Pitch 1/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1/4 in Number of Teeth 10 Outside Diameter 0.919 in Pitch Diameter 0.809 in Bore Type Fixed Chain Number 25 Finish Black Oxide Hub Diameter 1/2 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