Sprocket, Bore Diameter 1 1/4 in, For Chain Pitch 5/8 in, For Number of Strands Single, Hub Type One Side, Material Steel, Maximum Bore Diameter 1 1/4 in, Number of Teeth 40, Outside Diameter 8.32 in, Pitch Diameter 7.966 in, Bore Type Fixed, Chain Number 50, Finish Black Oxide, Hub Diameter 3 1/4 in, Hub Projection 0.907 in, Includes Set Screws, Keyway Yes, Keyway Depth 1/8 in, Keyway Width 1/4 in, Length through Bore 1 1/4 in, Number of Set Screws 2