Roller Chain Sprocket Bore Diameter 7/8 in For Chain Pitch 1/2 in For Number of Strands Double Hub Type One Side Material Steel Maximum Bore Diameter 7/8 in Number of Teeth 17 Outside Diameter 2.97 in Pitch Diameter 2.721 in Bore Type Fixed Chain Number 40-2 Finish Black Oxide Hub Diameter 2 1/8 in Hub Projection 0.659 in Includes Set Screws Keyway Yes Keyway Width 3/16 in Length through Bore 1 1/2 in