Disclosed is a method for producing hollow elements (200), such as nut elements, which are to be mounted on parts generally made of sheet metal, particularly for producing hollow elements having an at least substantially square or rectangular outer contour (202). According to said method, individual elements are cut to size from a profiled member that is provided in the form of a profiled bar or a reel after punching holes into said profiled member, optionally followed by embodying a threaded cylinder (206) using a follow-on composite tool (10) with several workstations (A, B, C, D). The inventive method is characterized in that a penetrating process, a punching process, and a flattening process are carried out in the workstations (A, B, C, D). Also disclosed are hollow elements (200), assembly pieces, and a follow-on composite tool (10).