Sprocket Bore Diameter 1/4 in For Chain Pitch 1/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 7/8 in Number of Teeth 20 Outside Diameter 1.729 in Pitch Diameter 1.598 in Bore Type Plain Chain Number 25 Finish Black Oxide For Pitch Type Single Pitch Hub Diameter 1 1/4 in Hub Projection 0.515 in Includes Set Screws Keyway Yes Length through Bore 5/8 in Material Grade 1045 Resistance Properties Corrosion Resistant