IDC Select® offers a wide range of high quality roller chain sprockets produced in ISO certified facilities to ANSI standards. Plain bore, finished bore, taper and QD® bushing designs are available. All IDC Select® sprockets come with hardened teeth and black oxide finish for long lasting service life. The finished bore design comes complete with a keyway on the centerline of the sprocket tooth and two setscrews, one over the keyway and one at 90 deg. IDC Select® Single Strand Roller Chain Sprocket, Finished Bore Type B, 1-1/8 in Bore Dia, 3.49 in Outside Dia, 60 Chain, 13 Teeth, 3/4 in Pitch, 3.134 in, 5/16 in Screw, 1/4 in W x 1/8 in D Keyway, 1-1/4 in Length Through Bore, C1045 Steel, Black Oxide