Abstract: A welding wire constituted by a core of welding powder enclosed by a mantle of metal is produced by forming an upwardly open metal channel composed of an outer channel and an inner channel abutting against the inner surface of the outer channel and having lateral flanks of a height which is about half the height of the lateral flanks of the outer channel, filling the inner channel with the powder, introducing a profiled metal band into the open channel which overlaps the powder in the inner channel and which engages the flanks of the latter at inner faces thereof so that the powder is enclosed by the inner channel and the profiled metal band, and bending upper longitudinal edges of the outer channel into abutment with each other. The longitudinal edges of the outer channel may be subsequently welded to each other, especially if the cross-section of the thus-produced wire is subsequently considerably reduced by passing it through drawing dies or the nip of pressure rolls.