PURPOSE: To provide a joint section excellent in mechanical strength by a slid-phase electromagnetic joining of metal pipe bars of different or the same kind after one joining end thereof is fitted into the other through a metal-coated layer with a given thickness.

CONSTITUTION: Either the inner surface of an end 1a of a pipe bar 1 made of A1 or the like or the outer surface of an end 2a of a pipe bar 2 with a smaller diameter than this made of copper or the like is coated with lead, tin, Ni, Cr, or Co or an alloy of these substances at a thickness ranging 2 to 20 μ by plating or the like. Then, the pipe bar 1 is fitted into the pipe bar 2 through the intermediate layer 11 thus formed. The section thus put together is arranged within a working coil 3 and subjected to an induction heating under a pressure to join the two pipe bars together. With such an arrangement, the mechanical nature of the metal compound formed between the joining surfaces of the pipe bars can be improved depending upon the thickness of the intermediate layer 11, thus achieving a solid-phase joining with an excellent strength.