Device for attaching together parts of a household electric appliance, one of which parts is a metal assembling part in the form of a sheet or plate having opposed first and second major faces, the device being composed of an assembling and retaining element having a base and a projecting portion which projects beyond the first major face of the assembling part, the assembling and retaining element being integral with, and formed from, said assembling part, wherein the base of the assembling and retaining element is constituted by a portion of the assembling part and extends to a plane containing the second major face of the assembling part, the projecting portion is formed by displacement of material of the assembling part to effect a local reduction of the thickness of the assembling part around the assembling and retaining element, and the projecting portion has a volume corresponding substantially to the volume of the material which is displaced to form the projecting portion. A heating appliance having parts secured together by the device.