Roller Chain Sprocket Bore Diameter 1 1/2 in For Chain Pitch 1 in For Number of Strands Double Hub Type One Side Material Steel Maximum Bore Diameter 1 1/2 in Number of Teeth 18 Outside Diameter 6.27 in Pitch Diameter 5.759 in Bore Type Fixed Chain Number 80-2 Finish Black Oxide Hub Diameter 4 5/8 in Hub Projection 1.04 in Includes Set Screws Keyway Yes Keyway Width 3/8 in Length through Bore 2 3/4 in