Roller Chain Sprocket Bore Diameter 1 3/8 in For Chain Pitch 3/4 in For Number of Strands Double Hub Type One Side Material Steel Maximum Bore Diameter 1 3/8 in Number of Teeth 15 Outside Diameter 3.98 in Pitch Diameter 3.608 in Bore Type Fixed Chain Number 60-2 Finish Black Oxide Hub Diameter 2 3/4 in Hub Projection 0.784 in Includes Set Screws Keyway Yes Keyway Width 5/16 in Length through Bore 2 1/8 in