The strand comprises a group of twisted metal wires, a plastic sheath and a pliant filling compound which fills internal interstices between the twisted wires of the group and a peripheral interstice lying between the periphery of the group and the inner face of the sheath. This peripheral interstice has, in a cross section of the strand, an area of between P×emin and 0.6×S2, where P is the external perimeter of the group of wires, emin=0.05 mm and S2 is the cumulative area of the gaps lying between the periphery of the group and the smallest circle within which the group is inscribed.