The practical application of low energy loss steels and an optimal magnetic core design are important, to minimize the energy losses in electrical machines. It is of great importance to reduce the deterioration of magnetic properties, during the magnetic core fabrication process. The influence of the cutting area on the energy losses was studied and it can be concluded, that the energy losses are strongly influenced by cutting technologies. There were tested sheet samples of M400-65A industrial steel grade (thickness of 0.65 mm), cut through mechanical and electrical discharge technologies. All samples have the length equal to 300 mm and the width of 30, 15, 10, 7.5 and 5 mm. The magnetic characterization was performed using a Brockhaus magnetic measurement unit, which can make measurements on samples with an area of 300 × 30 mm2. In order to have the standard width of 30 mm, there were put together side by side 2, 3, 4 and 6 pieces with different widths. The magnetic properties were analyzed at 250 mT, 500 mT, 1000 mT and 1500 mT in the frequency range 10 ÷ 200 Hz.

Keywords: Non-oriented electrical steels, Cutting area, Electrical discharge technology, Mechanical cutting, Energy losses