The grain oriented electrical steel is supplied with a thin inorganic coating on the glass film layer, which forms during annealing. A coating thickness of 2 to 5 μm provides good electrical resistance and a high stacking factor.
The coating, which is annealing resistant up to 840 °C, enables wound cores punched laminations to be stress relief annealed. The coating is chemically resistant to any fluid it may be exposed to during the production process. It is unaffected by, and likewise does not affect, the different types of transformer oils.
