These finished bore sprockets are shaft ready and come complete with keyways and setscrews. The keyways are on center line of the tooth. Bored to size sprockets with 1/2 in bores and smaller are stocked with (2) setscrews only. Martin Roller Chain Sprocket, Type B Bored-to-Size Single Strand Welded, 1-3/4 in Bore, 12.03 in OD, #80 Chain, 36 Teeth, 1 in Pitch, 11.4737 in Pitch Diameter, 4-3/4 in Diameter Hub, 3/8-16 x 3/8 in Screw, 3/8 x 3/16 in Keyway, 2 in Length Through Bore, Steel