Abstract: A method welds together two components of an internal combustion engine exhaust system, by resistance welding, to provide greater positioning freedom of two components welded together. A first component is provided with a welding area including an insertion opening edge surrounding an insertion opening. A second component is provided with a welding area including an insertion area to be inserted into the insertion opening. The insertion area is inserted into the insertion opening such that the insertion area is in contact with the first the entire insertion opening edge. An electrical voltage is applied to resistance weld the first component to the second component. The surface (28) of the insertion area is curved about two axes that are not parallel or is curved about an axis that is parallel to the surface of the insertion area, or/and an insertion surface of the insertion opening edge is located in one plane.

Abstract: A method welds together two components of an internal combustion engine exhaust system, by resistance welding, to provide greater positioning freedom of two components welded together. A first component is provided with a welding area including an insertion opening edge surrounding an insertion opening. A second component is provided with a welding area including an insertion area to be inserted into the insertion opening. The insertion area is inserted into the insertion opening such that the insertion area is in contact with the first the entire insertion opening edge. An electrical voltage is applied to resistance weld the first component to the second component. The surface (28) of the insertion area is curved about two axes that are not parallel or is curved about an axis that is parallel to the surface of the insertion area, or/and an insertion surface of the insertion opening edge is located in one plane.

Abstract: A method for manufacturing an exhaust gas converter and a tool for the method are provided. The method includes providing a cylindrical metal pipe and a cylindrical substrate surrounded in a circumferential direction by a mat mount. The substrate is deposited with the mat mount surrounding it inside the metal pipe. A compression force is exerted on the metal pipe, directed in a radial direction, for reducing the cross-section of the metal pipe to a desired size. Regions to which a compression force is applied alternate along the circumferential direction of the metal pipe with regions to which no compression force is applied. A number of regions where no compression force is applied to the metal pipe exceeds the number of tools used for applying the compression force. The tool (4), for a ring press, includes a tool body including a mounting section and a work section with recesses (45).