Sprocket, Bore Diameter 1 in, For Chain Pitch 1/2 in, For Number of Strands Single, Hub Type One Side, Material Steel, Maximum Bore Diameter 1 in, Number of Teeth 12, Outside Diameter 2.17 in, Pitch Diameter 1.932 in, Bore Type Fixed, Chain Number 40, Finish Black Oxide, Hub Diameter 1 9/16 in, Hub Projection 0.591 in, Includes Set Screws, Keyway Yes, Keyway Depth 1/8 in, Keyway Width 1/4 in, Length through Bore 7/8 in, Number of Set Screws 2