SHEET METAL STRUCTURAL MEMBER AND FRAMES INCORPORATING SAME

摘要

A sheet metal, elongate structural member is cold roll-formed from a strip of sheet metal no thicker than 1.2 mm, preferably 0.6 mm, comprising a central zone and two edge zones flanking the central zone and each having a free edge margin. The member comprises a substantially planar web (9), a first hollow flange (10) extending along one edge of the web (9) and projecting laterally to both sides of the web, and a second hollow flange (11) extending along the other edge of the web (9) and projecting laterally to one side only of the web. The web (9) comprises the central zone and the margins (17, 23) of the original strip secured flatly together by clinches (18, 29), and the hollow flanges are formed from the edge zones of the original strip excluding the margins thereof. The spacing of the clinches is selected so that the shear point of the member's section substantially coincides with the plane of the web.