Abstract: A corner angle assembly for a structure, such as a duct work, has first and second angle pieces inserted through the respective openings in triangularly-shaped connecting flanges spot-welded to the respective walls of the structure. A first piece is inserted into its respective flange and has a contact portion extending beyond the opening in the flange. This contact portion has a groove for slidably receiving the second angle piece. The second angle piece has an upwardly-extending edge engaging the first piece for limiting the degree of insertion of the second piece. The first piece has a protruding portion bent over a beveled edge on the second piece for precluding the withdrawal of the second piece. Cooperating aligned holes in the extending portions of the respective pieces facilitate the passage of bolts or other suitable securing means.

Abstract: In order to produce butt joints between two thin-walled sheet-metal tube sections (22), a one-piece flanged ring (10) is used, which substantially comprises only a securing flange (12) protruding approximately radially outward, an arm (14) projecting from the inner end of the securing flange and a ring land (18) bent obliquely outward toward the securing flange (12) by the arm (14). The outer diameter of the ring land (18) is selected such that when it is driven into the end of the tube, it comes under pre-stressing and thus produces a stable joint between the flanged ring (10) and the tube (22). The invention also encompasses a simple method for producing the flanged ring (10), in which an elongated, flat sheet-metal strip is first folded and then is bent into annular form, and further encompasses a butt joint, having two flanged rings (10) according to the invention, between two thin-walled sheet-metal tube sections (22).