Some of the largest manufacturing companies as of 2015 are 3M, Boeing, Caterpillar, General Electric and United Technologies. All of these companies are components of the Dow Jones Industrial Average stock index.
Boeing, 3M and Caterpillar all have important core businesses revolving around manufacturing. Boeing's focus is on aerospace manufacturing for both civilian and military markets, while Caterpillar manufactures construction and mining equipment as well as industrial diesel, gasoline and gas turbine engine systems. The diverse manufacturing interests of the 3M Corporation include adhesives, abrasives, medical products, automotive care products and electronic components.
General Electric and United Technologies are somewhat more diversified than the other large manufacturing companies included in the Dow Jones Industrial Index. While General Electric is best-known for its home appliance manufacturing business, GE is a major manufacturer of military technology, aviation products, medical devices and electrical power plant equipment. GE also has significant interests in the energy, entertainment and financial sectors, though the company has divested itself of many of these holdings in recent years. United Technologies is a major contractor for the United States military through its historical origin as United Aircraft and through aerospace technology units acquired from other companies. It also is a major manufacturer of heating and cooling equipment and owns security and fire protection companies Chubb and Kidd.