A cylindrical body includes a cylindrical member, made by forming a metal plate into a cylindrical shape such that the two end faces of the metal plate face each other, and a nonmetallic adhesive member bonding the two end faces together. The two end faces each include an adhesive part, and the adhesive member is disposed between the adhesive parts of the end faces. The adhesive part of one end face is not parallel to the adhesive part of the other end face. Each end face also includes a contact part which is in contact with the contact part of the other end face.

A metal plate includes: a recessed portion provided at one end surface by cutting out the metal plate in a planar direction of the metal plate, the recessed portion having an engaging portion inside the recessed portion; and a protruding portion provided at a position on another end surface, the position corresponding to that of the recessed portion, the protruding portion protruding in the planar direction, the protruding portion being engaged with the engaging portion by applying a bending process such that the engaging portion is hooked by the protruding portion, wherein a length from a proximal end portion to a distal end portion of the protruding portion before the bending process is applied is equal to or less than a depth of the recessed portion at a position of the recessed portion, the position facing an end surface of the proximal end portion of the protruding portion.

A system for automatically forming sheet metal tubes from blanks cut to size. The system having a mechanism for positioning a blank for processing. A lifting arrangement having a wrap strap and pressure pad to raise the blank to a forming station having a mandrel is positioned so that the wrap strap extends on either side of said mandrel and underneath the blank before a side wiper on each side of said mandrel forces the overlap of opposite edges of the blank along a length of the mandrel. The mandrel includes a clinching die bar along its length. A sealing mechanism with a vertically movable row of clinching prongs is lowered to attach the overlapping edges of the blank by clinching at multiple positions to form a tube around the mandrel before being removed by a gag bar and a stripper plate.

A metal plate includes: a recessed portion provided at one end surface by cutting out the metal plate in a planar direction of the metal plate, the recessed portion having an engaging portion inside the recessed portion; and a protruding portion provided at a position on another end surface, the position corresponding to that of the recessed portion, the protruding portion protruding in the planar direction, the protruding portion being engaged with the engaging portion by applying a bending process such that the engaging portion is hooked by the protruding portion, wherein a length from a proximal end portion to a distal end portion of the protruding portion before the bending process is applied is equal to or less than a depth of the recessed portion at a position of the recessed portion, the position facing an end surface of the proximal end portion of the protruding portion.

A system for automatically forming sheet metal tubes from blanks cut to size. The system having a mechanism for positioning a blank for processing. A lifting arrangement having a wrap strap and pressure pad to raise the blank to a forming station having a mandrel is positioned so that the wrap strap extends on either side of said mandrel and underneath the blank before a side wiper on each side of said mandrel forces the overlap of opposite edges of the blank along a length of the mandrel. The mandrel includes a clinching die bar along its length. A sealing mechanism with a vertically movable row of clinching prongs is lowered to attach the overlapping edges of the blank by clinching at multiple positions to form a tube around the mandrel before being removed by a gag bar and a stripper plate.