Roller Chain Sprocket Bore Diameter 1 3/16 in For Chain Pitch 1/2 in For Number of Strands Double Hub Type One Side Material Steel Maximum Bore Diameter 1 3/16 in Number of Teeth 45 Outside Diameter 7.45 in Pitch Diameter 7.168 in Bore Type Fixed Chain Number 40-2 Finish Black Oxide Hub Diameter 3 1/2 in Hub Projection 0.909 in Includes Set Screws Keyway Yes Keyway Width 1/4 in Length through Bore 1 3/4 in