Sprocket Bore Diameter 1 in For Chain Pitch 1 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 2 3/4 in Number of Teeth 25 Outside Diameter 8.52 in Pitch Diameter 7.979 in Bore Type Plain Chain Number 80 Finish Black Oxide For Pitch Type Single Pitch Hub Diameter 4 1/4 in Hub Projection 1.175 in Includes Set Screws Keyway Yes Keyway Depth 1/8 in Keyway Width 1/4 in Length through Bore 1 7/8 in Material Grade 1045