Roller Chain Sprocket Bore Diameter 1 15/16 in For Chain Pitch 1 1/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 15/16 in Number of Teeth 20 Outside Diameter 8.64 in Pitch Diameter 7.99 in Bore Type Fixed Chain Number 100 Finish Black Oxide Hub Diameter 4 1/2 in Hub Projection 1.371 in Includes Set Screws Keyway Yes Keyway Width 1/2 in Length through Bore 2 in Number of Set Screws 2