Grain oriented electrical steels are iron-silicon magnetic alloys. These alloys are used to construct the cores of highly-efficient electric transformers due to their unique magnetic properties. Available in grades M-2, M-3, M-4, M-5 and M-6, with superior magnetic properties in the rolling direction, oriented steels are used in transformer cores. They are used in large generators and other apparatus when the design permits the directional magnetic characteristics to be used efficiently.