... iron cores for power transformers and ballasts CertificateIS09001 ISO14001 silicon steel sheet1) Specifications: EI-28, EI-30, ... to international standards3) Materials (cold rolled grain non oriented silicon steel coils):BAOSTEEL: B50A1000, B50A800, B50A600, B50A470, B35A550 ... silicon steel coils, such as Chinese steel.4) Applicable to all kinds of iron cores for power transformers, rectifiers, ...