Slope control is the method of cushioning power during the resistance welding or fusing operation, when working with a machine that is designed to operate using the direct ac welding or fusing method. Fusing is a method of joining low resistance metals with a type of resistance welding machine, but without appreciable distortion of the parts being joined. Magnet wire is normally fused to terminals or commutators, without prior removal of the wire's film insulation. This insulation is removed by flash vaporization during the fusing process.