Single Strand Sprocket Bore Diameter 3/4 in For Chain Pitch 1/2 in For Number of Strands Single Hub Type One Side Material Steel Maximum Bore Diameter 3/4 in Number of Teeth 12 Outside Diameter 2.17 in Pitch Diameter 1.932 in Bore Type Fixed Chain Number 41 Finish Black Oxide For Pitch Type Single Pitch Hub Diameter 1 9/16 in Hub Projection 0.648 in Includes Set Screws Keyway Yes Keyway Depth 3/32 in Keyway Width 3/16 in Length through Bore 7/8 in Material Grade 1045