Abstract: A grinding foil comprising an abrasive medium on a flexible strip steel foil with a thickness of 0.05 to 0.25 mm and due to the properties of the strip steel foil has good thermal conductivity, thermal stability, tensile strength and selfadhesive properties on a permanently magnetic adhesive backing of a support member allowing fast-release attachment. Due to its ductility, fixing elements are produced in the foil at right angles to its surface and having the shape of inner flanges which engage in matching recesses in the support member, which further improves cooling and enables spot-accurate joining.

Abstract: A device for mixing flowable materials, especially relatively viscous liquids and flowable solids, comprises a pipe or tube section, preferably of circular cross section, provided internally with at least one mixing element helically twisted in a uniform manner about the axis of the pipe and formed with only two groups of surface regions which are folded relative to one another and which alternate along the mixing element. Each of these surface regions is of flat triangular outline with a base of the triangle formed along one of the helically twisted longitudinal edges of the mixing element and converging toward the other. The flat surface regions may be truncated, i.e. of generally trapezoidal outline with their narrow triangle side lying along the opposite edge of the mixing element from that occupied by the base, or of a pointed configuration where the triangle apex lies along this opposite side of the mixing element.