Roller Chain Sprocket Bore Diameter 30 mm For Chain Pitch 5/8 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 30 mm Number of Teeth 13 Outside Diameter 3 in Pitch Diameter 66.33 mm Bore Type Fixed Chain Number 10B Finish Black Oxide Hub Diameter 48 mm Hub Projection 0.623 in Includes Set Screws Keyway Yes Keyway Width 8 mm Length through Bore 25 mm Number of Set Screws 2