The absolute advantage of a DC demagnetizer lies in its exceptionally deep magnetic field penetration. Unlike AC demagnetization, which is limited to the workpiece surface by the skin effect, a DC magnetic field can uniformly penetrate the entire cross-section, achieving complete demagnetization of large, thick components. By progressively reversing the current and reducing it to zero, it generates a continuously shrinking hysteresis loop that thoroughly randomizes the internal magnetic domains, resulting in near-zero residual magnetism. This capability is irreplaceable for high-coercivity alloys, large castings and forgings, bearings, and molds, making it a truly reliable method for complete demagnetization both inside and out.