Abstract: A metal wire having the following features:(a) it is formed, at least in part, by a steel having a carbon content of at least 0.1% and at most 0.6% and a boron content of less than 8 ppm;(b) the steel of the wire has a strain-hardened lower bainite type structure (7);(c) the diameter of the wire varies from 0.10 to 0.40 mm;(d) the resistance to rupture of the wire is at least equal to 2800 MPa;(e) the elongation upon rupture of the wire is at least equal to 0.4%.The method according to the invention for producing this wire consists in strain hardening a machine wire having 28% to 90% proeutectoid ferrite and 72% to 10% perlite, thereupon carrying out a heat treatment to obtain a structure of lower bainite type, then effecting a strain hardening on the wire, the temperature of the wire upon the strain hardening being less than 0.3 T.sub.F, T.sub.F being the melting point of the steel expressed in Kelvin.