Stainless steel and Ti metal fibers having a diameter of 3 µm were produced from wires by multiple extrusions. The suitable sheath coating for stainless steel to extrude the core wires to fibers was the Cu coating having ~30 µm thickness. Zinc was not a suitable sheath coating, because Zn of the low melting point had diffused into the stainless steel wires during extrusion. The oxidation of stainless steel fibers produced using the Cu sheath coating oxidized rapidly above 750°C due to the high surface area of fibers. The utilization of the Cu coating as a sheath material to extrude the core Ti wires to fibers was not possible, because the highly reactive Ti wires resisted deforming to fibers.