A machine for manufacturing metal cords includes a supporting structure, a rotor engaged with respect to the supporting structure, a cradle fastened to the supporting structure, feeding devices operatively fitted on the cradle to feed a plurality of elementary wires from respective feeding spools, and at least one preforming device operatively engaged with the cradle and operating on at least one of the elementary wires in a section upstream with respect to a first end section of the stranding path. The elementary wires are driven onto the rotor according to a stranding path. The stranding path has end sections coinciding with the rotation axis of the rotor and a central section distanced from the rotation axis of the rotor. The at least one preforming device provides the at least one of the elementary wires a substantially sinusoidal deformation lying in a plane.