Non-oriented silicon steel has no magnetic anisotropy, mainly used as the iron core of the motor class. The thinner the thickness of the silicon sheet, the smaller the eddy current loss, but too thin and increase the hysteresis loss. Generally oriented silicon steel sheet thickness is 0.25~0.35mm, non-oriented silicon steel sheet for 0.35~0.5mm. The surface is smooth and the flatness of the shape has a great influence on the magnetism. Therefore, the quality of silicon steel is closely related to rolling process.