Roller Chain Sprocket Bore Diameter 38 mm For Chain Pitch 3/4 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 38 mm Number of Teeth 24 Outside Diameter 6.2 in Pitch Diameter 145.95 mm Bore Type Fixed Chain Number 12B Finish Black Oxide Hub Diameter 100 mm Hub Projection 1.137 in Includes Set Screws Keyway Yes Keyway Width 10 mm Length through Bore 40 mm Number of Set Screws 2