The present invention provides a pipe body of which the edge sections
contact with each other stably and which can be formed only by means of
only a press processing without performing a welding mass-producing,
wherein separation-prevented engagement due to deformation of at least one
of the engagement sections absorbs the spring back in the press
processing. Also, the present invention provides a pipe body, a metal
plate for the pipe body and a forming method of the pipe body using the
sheet metal for the pipe body. The pipe body includes a pair of edge
sections 1e, 1f forming closed end surface by means of contact with each
other, wherein surroundings of each edge sections 1e, 1f form a plane 1a
jointly when each edge sections 1e, 1f are in contact with each other, and
at the same time, engagement sections consisting of female engagement
section 1g and male engagement section 1h engaged with each other are
formed in the edge sections 1e, 1f, and the edge sections 1e, 1f get in
contact with each other closely by means of separation-prevented
engagement due to deformation of at least one of the female and male
engagement sections 1g, 1h.
