The invention relates to a rotary cutting head with wires for a brush cutter, grass trimmer, edge trimmer, hedge trimmer or the like, said head comprising a housing (1) containing a supporting body (2) comprising a system (3, 3′, 4, 4′, 12) for blocking at least two cutting or shearing wires, and a peripheral wall (6) allowing the or each wire to be wound around said wall in said head. Said blocking system comprises at least two movable blocking elements (3, 3′) that are independent from each other and each associated with a clamping surface (4, 4′) built into the supporting body (2) and comprising a clamping face (10, 10′) and a supporting face (11, 11′), and a single elastic body (12) that can exert stress on each clamping face (11, 11′) for clamping and blocking each wire.