Sprocket Bore Diameter 1/2 in For Chain Pitch 3/8 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 1 3/8 in Number of Teeth 25 Outside Diameter 3.19 in Pitch Diameter 2.992 in Bore Type Plain Chain Number 35 Finish Black Oxide For Pitch Type Single Pitch Hub Diameter 2 in Hub Projection 0.707 in Includes Set Screws Keyway Yes Keyway Depth 1/16 in Keyway Width 1/8 in Length through Bore 7/8 in Material Grade 1045