Method of manufacturing hollow body elements, section for use in the method, hollow body element, component assembly and die

Method for the manufacture of hollow body elements (11;

• 211;
• 411) such as nut elements for attachment to components (13;
• 213;
• 413) normally consisting of sheet metal, in particular for the manufacture of hollow body elements having an at least substantially square or rectangular outline by cutting individual elements to length from a section (10;
• 210;
• 410) present in the form of a profiled bar or a coil after prior stamping of respective holes (98;
• 298;
• 498) into the section and optionally with subsequent formation of a thread cylinder (110;
• 310;
• 510), wherein, prior to the punching of holes in the section, an upsetting process is carried out in order to produce by material flow a cylindrical projection (36;
• 236;
• 436) concentric to the intended punched hole at the side (12;
• 212;
• 412) of the section confronting the component in use,
• characterised in that
• the upsetting process, in which a cylindrical recess is formed by an upsetting stamp in one side of the section and a cylindrical projection at the other side of the section, is directly followed by the hole punching operation in which the section is holed in the region of the cylindrical recess by means of a hole punch and in that the diameter of the upsetting punch is so selected in the region of its end which carries out the upsetting so that it corresponds at least substantially to the diameter of the hole punch.