Roller Chain Sprocket, Bore Diameter 1 1/4 in, For Chain Pitch 1 in, For Number of Strands Single, Hub Type One Side, Material Steel, Maximum Bore Diameter 1 1/4 in, Number of Teeth 17, Outside Diameter 5.95 in, Pitch Diameter 5.442 in, Bore Type Fixed, Chain Number 80, Finish Black Oxide, Hub Diameter 4 in, Hub Projection 0.925 in, Includes Set Screws, Keyway Yes, Keyway Width 1/4 in, Length through Bore 1 1/2 in, Number of Set Screws 2