To simply tighten a groove part by performing the tightening making use of the stress generated in binding metals due to the stress generated by the press-fitting and work hardening generated by the deformation of projected and recessed bars to tighten plates using a simple lower hole.

Plates 1, 2, 3 are made of ductile, non-ferrous metal, e.g. copper and aluminum. A rivet 2 tightens the plate 1 with the plate 2 without overlapping them, and a rivet 3 tightens the plate 2 with the plate 3 in an overlapping manner. Recessed and projected bar parts 2c, 2d, 3c, 3d which are corresponding to each other are provided on the joining surface of the metallic plates 2, 3 to be joined. The projected bar parts 2c, 2d, and/or the recessed bar parts 3c, 3d are provided with a part with the prescribed angle. Metals are bonded with each other by the stress generated by the press-fitting in press fitting the projected bar parts 2c, 3c into the corresponding recessed bar parts 2d, 3d, and by working hardening caused by the plastic deformation generated by the deformation of both parts at a corner part. Bonding is performed making use of work hardening thereby to produce rivets at a low cost.