American advanced-technology company that manufactures aerospace and automotive products; residential, commercial, and industrial control systems; specialty chemicals and plastics; and engineered materials. The present company was formed in 1999 through the merger of AlliedSignal Inc. and Honeywell Inc. Headquarters are in Morristown, New Jersey.

Among Honeywell's products are building controls (including heating, ventilating, and air-conditioning systems), electronic switches and motors, alarms, industrial automation systems, microelectronics, medical instruments, military and commercial avionics, and space systems. The company's control equipment for defense applications ranges from missile and bomb guidance systems to cockpit displays and optical and electronic sensors. It is a major producer of auxiliary power units for aircraft (used for main engine starting, cabin cooling, and electric power generation), turbofan and turboprop engines for business and regional aircraft, engine control systems, environmental control systems for aircraft and spacecraft, and wheels and brakes for commercial and military aircraft. Its automotive products include truck brakes, turbochargers, oil and air filters, spark plugs, air bags, and seat belt systems. The company also produces a variety of fibres, plastics, and specialty chemicals. In 2000 it employed about 125,000 people worldwide.

At the time of its merger with AlliedSignal, Honeywell already was the world's leading provider of control technologies for buildings and industry and a premier maker of avionics systems for aircraft and spacecraft. Its heritage dates to 1886 when Albert M. Butz, an American inventor who pioneered the use of thermostats to regulate furnace dampers, formed the Butz Thermo-Electric Regulator Company. The company subsequently underwent a series of ownership changes and expanded its product line, and in 1912 it became Minneapolis Heat Regulator Co. In 1906 the American engineer Mark C. Honeywell formed Honeywell Heating Specialty Co, which specialized in hot-water heat generators. The two firms merged in 1927 to create Minneapolis-Honeywell Regulator Co., which in 1934 acquired the Brown Instrument Co. (founded 1859), a maker of industrial controls and indicators.

In 1942, as a defense contractor for the U.S. government, Minneapolis-Honeywell created the first production automatic pilot, and in 1958 its flight controls helped launch the first American satellite, Explorer 1. In 1954 it added gyroscopes to its product line with the acquisition of Dolecam Corp. A year later it formed a joint venture with Raytheon (Raytheon Company) to build computer systems; it remained in the computer business, first in mainframes and then briefly in personal computers, until 1991. The company changed its name to Honeywell Inc. in 1963. In 1986 Honeywell purchased Sperry Aerospace Operations, another major supplier of aerospace guidance and navigation equipment, from Unisys.

The history of AlliedSignal begins in 1920 with the amalgamation of five leading American chemical manufacturers to form Allied Chemical & Dye Corporation. The new company, created by the financier and governmental adviser Eugene Meyer (Meyer, Eugene) and the scientist William Nichols, came in response to the shortages of chemical commodities, such as dyes and drugs, that had been experienced in World War I because of Germany's control over the world's chemical industry. The five firms were Barrett Company (founded 1903 as American Coal Products Company), supplying coal tar chemicals and roofing; General Chemical Company (founded 1899), specializing in industrial acids; National Aniline&Chemical Company (founded 1917), producing dyes; Semet-Solvay Company (founded 1894), manufacturing coke and its by-products; and Solvay Process Company (founded 1881), producing alkalies and nitrogen materials.

In 1928 Allied Chemical&Dye opened a synthetic ammonia plant to become the world's leading producer of ammonia. Following World WarII, it expanded its product range to include nylonand refrigerants. The company was renamed Allied Chemical Corporation in 1958. Four years later Allied purchased Union Texas Natural Gas, which owned oil and gas properties. The company was originally procured to ensure a supply of raw materials for Allied's chemical products, but by 1979, after Allied's divestiture of unprofitable chemical divisions, Union Texas accounted for 80 percent of its parent company's income. As a result, Chemical was dropped from the corporate name in 1981.

In 1983 Allied Corporation purchased Bendix Corporation, a major producer of automotive and aerospace equipment. By the following year Bendix accounted for about 50 percent of Allied's income, while oil and gas exploration and production generated about 38 percent. Bendix was formed in 1924 when the company's founder, the American inventor Vincent Bendix (Bendix, Vincent), joined with the French inventor Henri Perrot to manufacture brake systems. By 1928 the company was producing more than three million brakes per year, chiefly for General Motors Corporation. In 1928 Bendix acquired control of Eclipse Machine Company, which had been making Vincent Bendix's automotive starter since 1914. In 1929 the company turned to aviation products and changed its name to Bendix Aviation Corporation (not reverting to the name Bendix Corporation until 1960).

In 1985 Allied Corporation combined with Signal Companies (Signal Companies, Inc., The) in a transaction that was the largest industrial merger to that time. It also sold 50 percent of Union Texas (and its remaining interest in 1992), and in 1986 it completed the divestiture of 35 of its diverse subsidiary operations, permitting it to concentrate on its growing aerospace, electronics, and automotive operations. The combined company, initially named Allied-Signal, was renamed AlliedSignal in 1993 to indicate the full integration of its business units. Signal Companies had its start as the Signal Gasoline Company, a regional gasoline company in California founded by Sam Mosher in 1922. In 1928 the company entered oil production and was renamed Signal Oil & Gas. It expanded largely through numerous mergers and acquisitions. Signal's entry into the aerospace business began in 1964 with its merger with Garrett Corporation, a maker of gas turbines, control systems, and other aircraft and missile components. The name Signal Companies was adopted in 1968. In 1975 the company acquired controlling interest in UOP Inc. (formerly Universal Oil Products Company), a provider of technology for the petroleum-refining and petrochemical industries, and in 1981 it acquired Ampex Corporation, a manufacturer of audio and video, data-memory, and magnetic-tape products.