A strand of section of no more than 0.35 mm2 is provided having one or more electrical conductor wires, where each electrical conductor wire is constituted by an alloy of copper and tin. The tin content is not less than 1500 ppm and not more than 2500 ppm the oxygen content is not more than 400 ppm the inevitable impurities content is not more than 100 ppm and the balance of the content of the alloy is copper with the electrical conductor wire(s) being exempt from heat treatment during fabrication of the strand.