Roller Chain Sprocket Bore Diameter 1 1/8 in For Chain Pitch 1/2 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 1/8 in Number of Teeth 54 Outside Diameter 8.88 in Pitch Diameter 8.599 in Bore Type Fixed Chain Number 40 Finish Black Oxide Hub Diameter 3 1/2 in Hub Projection 0.841 in Includes Set Screws Keyway Yes Keyway Width 1/4 in Length through Bore 1 1/8 in Number of Set Screws 2