Roller Chain Sprocket Bore Diameter 1 1/4 in For Chain Pitch 1 1/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 1/4 in Number of Teeth 19 Outside Diameter 8.24 in Pitch Diameter 7.595 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 1/4 in Length through Bore 2 in Number of Set Screws 2