The single shear described herein for cutting and simultaneously conveying one or more pairs of rolling wires or bars (1, 2), comprises the following parts: a mobile diverter (5) consisting of at least two channels (6, 7) in each of which a wire or bar (1, 2) slides; at least two pairs of counter-knives (3, 4) each of which acts on a wire or bar (1, 2); a conveying device (9) for conveying the cut segments of wires or bars (1, 2), comprising - at least one pair of mobile elements (20, 20') configured to be independent of each other and synchronized with each other and with the mobile diverter (5), for the separate management of each of said cut sections of wires or bars (1, 2), and - at least two pairs of output channels (A1, A2, B1, B2) for conveying the cut segments of wires or bars (1, 2).