Abstract: A method of fabricating composite metal wires such as aluminium clad steel wires is disclosed which comprises providing a core of hard metal with a cladding of soft metal by extrusion. In fabricating a composite metal wire by extrusion, a core is generally aligned, polished, cleaned or otherwise pretreated before entering an extruder so that a high and variable tension is imparted to the core. By avoiding such tension variation and maintaining the core under a constant low tension and by electrically heating the core before the core enters the extruder, a composite metal wire of improved quality is fabricated in a stable manner.