Abstract: The invention relates to a method of preparation of an outer cover of a fusion roller for a xerographic machine, this cover being constituted by a homogeneous layer covering a hollow metal core receiving heating means.According to the invention, this method comprises the steps of (a) cold kneading a mixture having, for 100 parts of fluorine-containing rubber, 55 to 60 parts of carbon black, 2 to 6 parts of magnesium oxide, 4 to 8 parts of calcium hydroxyde and 0 to 2 parts of polyethylene wax; (b) forming the covering material by extrusion or calendering of this mixture; (c) application of this material in a homogeneous layer to the surface of the metallic core of the roller; (d) vulvanization at elevated temperature and under pressure of the material thus applied to the core; (e) dressing of the cover to a constant thickness.