Abstract: A process for producing a catalyst by providing a monolith with a polygonal cross section, tightly enclosing the monolith with a single part jacket made of metal sheet or plate, placing a layer of expanded matting between the jacket and the monolith, bending the jacket with at least one of a bending and a clamping device into a proper final shape so that edges of the jacket which extend at least essentially in a longitudinal direction of the monolith at least contact each other, and undetachably joining the edges to each other.

Abstract: The invention relates to a jacket-shaped middle part (1) of a catalytic converter housing, in particular for exhaust systems for internal combustion motors in motor vehicles. The jacket-shaped middle part (1) comprises a sheet metal plate, which incorporating an intermediate layer (4) made of an equalising material, is wrapped around a monolith made of ceramic material and encloses said monolith under initial radial tension, wherein the marginal regions (5, 6) of the jacket-shaped middle part (1) mutually overlap and are welded together. The sheet metal thickness in the overlapping marginal regions is reduced to such an extent, and in that the marginal regions are mutually and vertically offset in relation to the outside of the sheet metal plate, that the sheet metal thickness of the jacket-shaped middle part remains the same around the entire circumference, also in the overlapping region (2).

Abstract: A process for producing a catalyst by providing a monolith with a polygonal cross section, tightly enclosing the monolith with a single part jacket made of metal sheet or plate, placing a layer of expanded matting between the jacket and the monolith, bending the jacket with at least one of a bending and a clamping device into a proper final shape so that edges of the jacket which extend at least essentially in a longitudinal direction of the monolith at least contact each other, and undetachably joining the edges to each other.