Saint-Chamond (săN-shämäNˈ) [key], city (1990 pop. 39,262), Loire dept., SE France, at the confluence of the Gier and Janon rivers. The city was originally developed in the 19th cent. as a coal-mining center. Its products now include specialty steel construction components, military equipment (tanks), plastics, dyes, and textile products. The remains of a Roman aqueduct are in Saint-Chamond.