Starting in 1771 the Neyrand brothers had become owners of several coal mines and ironworks in the valley of the
Gier river. The community became a center of a region of coal and iron production in the 19th and 20th centuries, stimulating its industrialization and growth. In 1837 H. Pétin and J. M. Gaudet, mechanics and forgers, set up shops at Saint-Chamond and
Rive-de-Gier. In 1841 Pétin et Gaudet introduced one of the first
steam hammers at their works. Later they introduced innovations such as a mobile crane for moving large pieces around the works, and a hydraulic press. The company of Neyrand frères et Thiollière was formed in January 1845 to exploit an enlarged and modernized factory at
Lorette. These companies merged on 14 November 1854, forming the
Compagnie des Hauts-fourneaux, forges et aciéries de la Marine et des chemins de fer. The company, which engaged in extracting, processing and selling iron and coal, was initially based in Rive-de-Gier. On 9 November 1871 it moved its headquarters to Saint-Chamond and became a limited company. The factories were mainly concentrated in the
Loire basin, in Saint-Chamond and Assailly. In 1880 Saint-Chamond was the world capital of the lace industry. This industry was founded by
Charles François Richard, assisted by his son Ennemond Richard. Eighteen years later, the Manufactures Réunies company was formed by merging ten of the largest manufacturers of lace. During
World War I (1914-1918) the steel company built several different types of weapons, notably the
Saint Chamond-Mondragón 75 mm gun, which had been designed mostly by colonel Rimailho, the
Saint-Chamond tank, and the
Chauchat machine rifle. They also produced naval guns, such as the quadruple-gun turret design for the unfinished s. Industrial restructuring affected the region in the postwar period, as costs rose for mining. In the 1950s the city's last mine at Clos Marquet was closed. The steelworks became part of the Creusot-Loire group, which had 28 factories and 39,000 employees in the region, including 3,100 in Saint-Chamond. ==Twin towns==