Single Strand Sprocket Bore Diameter 1/4 in For Chain Pitch 1/4 in For Number of Strands Single Hub Type One Side Material Stainless Steel Maximum Bore Diameter 3/4 in Number of Teeth 18 Outside Diameter 1.568 in Pitch Diameter 1.44 in Bore Type Plain Chain Number 25 For Pitch Type Single Pitch Hub Diameter 1 1/8 in Hub Projection 0.39 in Includes Set Screws Keyway Yes Length through Bore 1/2 in Material Grade 304 Set Screw Location 90 Degrees from Keyway Set Screw Size -