... Taiwan with high quality silicon steel sheet, the main material for the 0.35 thick H18, H14, H12, Z11's high ... the transformer design to achieve the best performance. (Conventional material for Taiwan's strong piece of steel H18 0.35 thick ... F-level (155 °C), H-level (180 °C), HC-level (200 °C), C-level (220 °C). (Class B rating for general temperature 135 °C) 3) insulating material ...