Stewart-Warner is a US manufacturer of vehicle instruments, a.k.a. gauges. The company was founded as Stewart & Clark Company in 1905 by John K. Stewart. Their speedometers were used in the Ford Model T. In 1912 John Stewart joined with Edgar Bassick to make vehicle instruments and horns. Bassick owned Alemite Co and Stewart had bought the Warner Instrument Company, thus the name was changed to Stewart-Warner Corporation. The company started in Chicago and built a manufacturing plant on Diversey Parkway. The building kept expanding and finally covered one-million square feet (93,000 m²) and six floors. They also made radios and refrigerators, and produced the ubiquitous "zerk" grease fitting, named after its inventor, associated with the company. In the last years of the company's Chicago factory, it owned a number of aging six-spindle Brown & Sharpe and New Britain screw machines.
They also made heat exchangers starting in the 1940s under the "South Wind Division", but since then it became independent of its parent. They still use the Stewart-Warner name, and the web site is hyphenated: http://www.stewart-warner.com/
In the 1980s the company was bought by BTR plc who in the early 1990s decided to relocate to Juarez, Mexico and Stewart-Warner was taken over by another management team. In early 1998 Stewart-Warner was bought by Datcon Instrument Company (later renamed to Maxima Technologies), but kept the Stewart-Warner brand.