Abstract: The invention relates to an elongate retaining element for building sheets, having, as seen in cross section perpendicular to its direction of elongation, a heard part (1) for engaging at least one said building sheets, a base part (3) for mounting the elongate retaining element on a support structure, and a connecting flange (2) extending upwardly from said base part (3) and joining said head part (1) to said base part (3). The elongate retaining element is made from a plastic material, such as PA, and has a reinforcement sheet (4), such as a metal sheet, extending from the connecting flange (2) into at least the head part (1). As seen in cross section, in the head part one free end (5) of the reinforcement sheet is bent into a section with an acute angle of less than 90°.

Abstract: The invention relates to an elongate retaining element for building sheets, having, as seen in cross section perpendicular to its direction of elongation, a heard part (1) for engaging at least one said building sheets, a base part (3) for mounting the elongate retaining element on a support structure, and a connecting flange (2) extending upwardly from said base part (3) and joining said head part (1) to said base part (3), and wherein said elongate retaining element is made from a plastic material, such as PA, and has a reinforcement sheet (4), such as a metal sheet, extending from the connecting flange (2) into at least the head part (1), and wherein, as seen in cross section, in the head part one free end (5) of the reinforcement sheet is bent into a section with an acute angle of less than 90°.

Abstract: Disclosed is an elongate retaining element for building sheets, having in plane perpendicular to its direction of elongation, a head part which is substantially triangular in cross section. The head part including one or more movable rotationally symmetrical elements. The movable rotationally symmetrical elements are positioned at one or more vertices of the triangle. The head part includes one or more mountings in which the elements for engaging the building sheet are mounted. The mountings are attached to the head part by fixing elements.

Abstract: The invention relates to a metal sheet for building purposes, comprising a panel and two standing flanges lengthwise at opposite sides of the panel. According to the invention one or both flanges have a non-rectilinear form in the plane of the panel. The invention also relates to a method and an apparatus for forming such metal sheets.

Abstract: A method for applying a zinc layer onto an aluminum or aluminum alloy sheet, comprising pretreating the surface and applying the layer by electrolytic galvanizing, the pretreating comprises electrochemical graining of the surface, for example in a solution having a pH less than 3 with an alternating current applied between the sheet and an electrode. In an alternative method, the pretreating includes applying a preliminary zinc layer by immersing the surface in a zinc-containing alkaline solution, applying a potential to the sheet and reversing the polarity of said potential at least once. The sheets are useful for building cladding sheets and automotive panels.