Sprocket, Bore Diameter 1 1/2 in, For Chain Pitch 5/8 in, For Number of Strands Single, Hub Type One Side, Material Steel, Maximum Bore Diameter 1 1/2 in, Number of Teeth 21, Outside Diameter 4.52 in, Pitch Diameter 4.194 in, Bore Type Fixed, Chain Number 50, Finish Black Oxide, Hub Diameter 3 in, Hub Projection 0.657 in, Includes Set Screws, Keyway Yes, Keyway Depth 3/16 in, Keyway Width 3/8 in, Length through Bore 1 in, Number of Set Screws 2