... for power transformers and ballast CertificateIS09001, ISO14001 silicon steel sheet:1) Specifications: EI-24, EI-28, ... international standards3) Materials (cold rolled grain non oriented silicon steel coils):a) Baosteel: B50A1000, B50A800, B50A600, B50A470, ... 50WW470, 350WW360, 350WW310d) An steel: 50AW1300, 50AW1000, 50AW800, 50AW600, 50AW470e) Imported silicon steel coils, such as Chinese steel4) ...