... , B50A470, B35A550, B35A440 b) Tai steel: 50TW800, 50TW600, 50TW1000, 50TW470 c) Wu steel: 50WW1300, 50WW800, 50WW600, 50WW470, 350WW360, 350WW310 d) An ... steel.4. Applicable to all kinds of iron cores for power transformers and ballasts. EI lamination (silicon steel product)