PURPOSE: To connect efficiently bar-like bodies in a short time, by moving a tubular convering member for connection provided with bulge to the butt parts of the two bar-like bodies which are heated to the melting point from the one bar-like body and pressing both bar-like bodies in the longitudinal direction thereof thereby filling the butt end parts in said bulge.

CONSTITUTION: Bar-like bodies or reinforcing bars 8, 9 are butted to each other and a covering member 10 which has an inside diameter larger than the diameter of said bars and is formed with a bulged part 10' internally at the center is passed onto the one reinforcing bar and is held thereon. The parts 8', 9' to be connected of the bars 8, 9 are butted to each other and the butt parts are heated by an oxy-acetylene flame or the like. When the end parts 8', 9' attain the m. p., the member 10 is moved and is stopped in the position where the outside in the butt parts of the bars 8, is enclosed by the part 10'. In succession, both bars 8, 9 are pressed in the direction of the parts 8', 9' from both sides in the longitudinal direction to expand the outside circumferential parts in the parts 8', 9' and to fill the same in the part 10', whereby both bars 8, 9 are connected.