These finished bore sprockets are hardened, 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 Single Pitch Roller Chain Sprocket, Bored-to-Size Type BS, 1/2 in Bore Dia, 1.746 in Outside Dia, #35 Chain, 13 Teeth, 3/8 in Pitch, 1.567 in, 1-1/4 in Hub Dia, 1/4-20 x 1/4 in Screw, 1/8 x 1/16 in Keyway, 3/4 in Length Through Bore, Steel