importance of insulating coatings on non-oriented electrical steels even though some of these analyses did not evaluate directly the motor performance [1]-[3]. Small induction motor manufacturers due to cost restrictions largely consume the semi-processed electrical steel. In this case, laminates are usually heat-treated (decarburized) after the punching process, in order to reduce the carbon content and to increase the grain size as shown in Figure 1, both intended to reduce hysteretic losses. The elimination of burrs also takes place during the decarburizing process. Another important step at decarburizing furnace is the production of a thin, but usually good quality, Fe3O4 oxide layer to provide electrical insulation between laminates. The decarburizing process described above is worthwhile for stator laminates, which carry flux at line frequency, leading to significant iron losses in the stator cores. However, this process can be hardly justified for rotor laminates, due to cost-benefit reasons, since flux variations in most of rotor cores are of low frequency.