Abstract: An electrode roll for an electric resistance seam welding machine comprises a stator substantially made of copper or a copper alloy, a rotor mounted on the periphery of the stator, and substantially or in part made of copper or a copper alloy and rotatably a gap portion formed by the stator and the rotor. A conductive liquid metal, which is a fusible alloy composed mainly of gallium, is inserted in the gap portion through a filling hole and is sealed in the gap portion. At least the portion of the filling hole that may come in contact with the conductive liquid metal is fabricated of a metal or metal alloy which is hard to be corroded by the fusible alloy. The remaining surfaces of both rotor and stator facing the gap portion are covered with a layer or layers of a metal or metal alloy that is hard to be corroded by the fusible alloy. In at least one embodiment, such layer or layers are further covered with another thin layer of metal which has an excellent wettability by the fusible alloy.

Abstract: An electrode roll for electric resistance welding which contains a stator member at least partly made of Cu or Cu alloy, a rotor member at least partly made of Cu or Cu alloy and rotatably mounted on the stator member, and a fusible alloy mainly composed of gallium and filling as a conductive medium an annular gap between the stator and rotor members, and portions of those two members facing the gap and being made of Cu or Cu alloy are covered by an alloy layer containing Co and W in weight proportions of 90:10 to 30:70.