The Société Alsacienne de Constructions Mécaniques (SACM) [Society of Alsatian mechanical engineering] is an engineering company with its headquarters in Mulhouse, Alsace which produced railway locomotives, textile and printing machinery, diesel engines, boilers, lifting equipment, firearms and mining equipment. SACM also produced the first atomic reactor at Marcoule.
The company was founded by André Koechlin in 1826 to produce textile machinery. In 1839, he opened a factory to build railway locomotives at Mulhouse in Alsace. The business grew rapidly but in 1871, the annexation of Alsace-Lorraine by Germany, brought about the transfer of some production to Belfort in France. In 1872 the company merged with the Graffenstaden company of Illkirch-Graffenstaden (a suburb of Strasbourg) to form SACM.
The new company diversified into the production of boilers, steel equipment, printing equipment, compressors, firearms and other engineering products growing to 4500 employees by 1910. A new foundry was built in 1922 for textile machinery. In 1928 the Thomson-Houston Electric Company merged with the Electrical Engineering division of SACM to form a new company named Alsthom, (Alsace-Thomson), later changed to Alstom.