Sprocket, Bore Diameter 3/8 in, For Chain Pitch 1/4 in, For Number of Strands Single, Hub Type One Side, Material Steel, Maximum Bore Diameter 1 3/8 in, Number of Teeth 40, Outside Diameter 3.327 in, Pitch Diameter 3.187 in, Bore Type Plain, Chain Number 25, Finish Black Oxide, For Pitch Type Single Pitch, Hub Diameter 2 in, Hub Projection 0.64 in, Includes Set Screws, Keyway Yes, Keyway Depth 1/16 in, Keyway Width 1/8 in, Length through Bore 3/4 in, Material Grade 1045