The Company commenced operations in 1942 in a small plant in the Montréal suburb of Longueuil where it manufactured machined parts for a variety of military purposes. Over the years, the Company availed itself of various government programs to develop its business. It began to specialize in the aeronautical industry in the 50's. During the 1960's, the Company designed, developed and manufactured servomechanisms and the landing gear for the CL-215 water bomber built by Canadair Limited and for the DHC-6 Twin Otter built by De Havilland (both now divisions of Bombardier Inc.). During this period, the Company was awarded the contract to manufacture the landing gear for the Apollo Lunar Module designed by the National Aeronautics and Space Administration (NASA).

In June 1985, all of the Company's outstanding shares held since 1973 by Bombardier Inc., were acquired by Mr. Sarto Richer and Mr. Gilles Labbé, both senior executives of the Company.

In December 1986, the Company made its initial public offering of common shares to finance among other things the modernization of its facilities. As a result, the Company became a public entity whose common shares were listed on the Montréal Exchange.

The Company recognized a need to reduce its reliance on the military market. It therefore established the objective of diversifying its operations to include the commercial and industrial sectors and sought to establish U.S. operations. In November 1987, Héroux expanded into the United States through the acquisition of McSwain Manufacturing Corporation in order to diversify its operations and to be closer to its main American customers. McSwain Manufacturing Corporation, with facilities located in Cincinnati, Ohio, specializes in the manufacture and sale of high-precision machined parts for the power generation, heavy machinery and aerospace industries.

On June 3, 1999, the Company acquired Métro Machining Corporation and Les Industries C.A.T. inc., specializing in aircraft structural components. These two acquisitions became the foundation of the Aerostructure Division.

In June 2000, Héroux announced the successful completion of its take-over bid for all of the shares of Devtek Corporation. In September of that year, Héroux Inc. changed its name to Héroux-Devtek Inc.

On April 1, 2004 the Company announced the closing of the acquisition of Progressive Inc., a Texas-based manufacturer of large components to military aircraft OEM. The acquisition strengthened Héroux-Devtek's Aerostructure Division by providing access to the important military aerospace sector and its aircraft platform.