This sector represents the historical core business as LEF was born dedicating its activity to the construction of electromechanical transformers and stabilizers for the industrial sector, specializing in the supply of custom products. An important milestone was achieved with the achievement of the UNI 9001: 2008 company certification first, and, subsequently, UNI ISO 9001: 2015, ISO 14001: 2015 and BS OHSAS18001: 2007 up to the recent ISO 27001: 2013 certification.
Furthermore, in 2004 it was possible to affix the prestigious ENEC quality mark, recognized by 22 European countries, to the transformers of the TS and TI series.

In the industrial sector, LEF Group has increasingly consolidated its credibility, placing itself among the main suppliers of public and private entities, thanks to a qualified internal technical-commercial staff constantly engaged in the research and study of new products that are always "current" and in in line with the demands of the reference market sectors, both in the private industry and in the distribution of electrical equipment.