Iran Transfo Corporation was established in 1966 under license of Siemens-Germany as a manufacturer of oil -immersed distribution, Medium and Large power transformers with the primary objective of designing, calculating and manufacturing of all type of transformers according to the international Standards of IEC76 & VDE 0532. Construction of the transformer plant was started in Zanjan for design and manufacturing of oil-immersed Distribution, Medium and Large Power transformers in 1976. Iran Trnsfo has been became Group of manufactures Including three factories and is set 13 companies.