Erhardt developed a significant industrial branch, encompassing investments in engineering firms, workshops, and factories. This area was led by Alberto Erhardt, who, in 1971, by agreement between the two brothers, became the sole shareholder of the companies within the Industrial Area.
The flagship company was Mecánica de La Peña, dedicated to the design and manufacture of industrial equipment and turnkey plants. This third generation of the Erhardt brothers, together with the Sendagorta brothers, participated in the creation of the engineering firm SENER, now a global leader in aerospace. Other companies within the Engineering and Industry branch included ERPO, Talleres Moreda, Talleres Serantes, TAMESE, MECANER, EINSA, INDESA, SACES, SINOR, among others.