A method of joining a plurality of hot materials to be rolled to each other, in which a trailing end of a preceding one of said hot materials and a leading end of an adjacent succeeding one of said hot materials are joined to each other on a line of a continuous hot rolling system, wherein the method comprises:
- (a) a first step of preparing at least one melt-cut torch for forming an injected flow of cutting gas;
- (b) a second step of setting said melt-cut torch in a predetermined positional relationship with respect to the trailing end of said preceding hot material and the leading end of said succeeding hot material;
- (c) a third step of blowing the injected flow of said cutting gas against a portion of at least one of the trailing end of said preceding hot material and the leading end of said succeeding hot material to melt-cut said portion, said portion extending from an end surface of the one end over a predetermined width in a longitudinal direction of said hot materials;
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- (d) a fourth step of forcing the trailing end of said preceding hot material and the leading end of said succeeding hot material, at least one of which has said melt-cut portion, against each other to butt-join said trailing and leading ends to each other.