Metal plate and method of producing tubular body

A method of manufacturing a tubular body formed from a metal plate, the tubular body having

• a recessed portion provided at one end surface of the metal plate by cutting out the metal plate in a planar direction of the metal plate;
• and
• a pair of protruding portions provided at a position on another end surface of the metal plate, the position corresponding to that of the recessed portion, the pair of protruding portions protruding in the planar direction,
• wherein a length from a proximal end portion to a distal end portion of the pair of protruding portions is less than a depth of the recessed portion located at the position corresponding to that of the protruding portion,
• wherein the method comprising:
• a first step of bending the metal plate to face the one end surface to the another end surface and entering the pair of protruding portions into the recessed portion, and
• a second step of inserting a pressing member between the pair of protruding portions along a plate thickness direction, the pressing member being configured to press the pair of protruding portions such that the pair of protruding portions move apart from each other by deforming the pair of protruding portions to be abutted with a wall of the recessed portion and bent by a taper portion of the pressing member, the taper portion being inclined with respect to an entering direction of the pressing member and such that an engaging portion provided in the recessed portion is hooked by the pair of protruding portions.