Stress-relief annealing is not always necessary. Whether or not it is required depends upon thickness, size and type of lamination or core, and the required magnetic properties. Stress-relief annealing always incurs the possibility of impairing lamination flatness unless special precautions are taken to preserve or improve flatness during annealing. However, if the full magnetic properties of a grade are required, stress- relief annealing is necessary, particularly when the lamination width is less than one inch. The user must decide, based upon his specific requirements