Rolls-Royce Limited was established by Charles Rolls and Henry Royce in 1904. The company designed and built luxury cars and with the help of Henry Royce’s previous experience in building cranes, it soon gained widespread reputation for engineering excellence. During the First World War Rolls-Royce added building aero engines to its skills. This enabled them to later become involved in the development of jet engines. They worked engines for both the civilian and military market. However, a costly over-run in designing and building the RB211 civilian aircraft engine brought the company to financial ruin. Even though the RB211 proved a great success in 1971 the owners of the company entered voluntary liquidation. The government of the day bought the productive parts of the company which became known as Rolls-Royce (1971) Limited. Portions of the company were sold to British Aircraft Corporation and transferred the profitable car division to Rolls-Royce Motors Holdings Limited. In 1987 Rolls-Royce Ltd was privatised and subsequently became Rolls-Royce plc. The Rolls-Royce Motors brand was bought by BMW in 1998.

Brin’s Oxygen Company was formed in 1886 to exploit the patent rights for a process developed by Arthur and Leon Brin, two French brothers, after they had taken out a patent for the process of separating oxygen, known as the Brin process. A little later a German engineer, Carl Von Linde developed a new cryogenic separation process for which he won the patent rights, the Brin brothers negotiated an agreement with Linde to use the new process which entailed giving Linde a stake and a position on the board of the company. He held this position until 1914. In 1906 the Brind brothers changed the name of the company to the British Oxygen Company or BOC as it is better known. The company grew on the development of the oxyacetylene welding process brought out in 1903. In 1969 the name was shortened to BOC the company continued to prosper and in 1978 it acquired Airco Industrial Gases and the enlarged company changed its name to BOC group. In 2006 the Linde Group made a proposal to acquire the BOC Group and after a second proposal BOC agreed and it became a part of the Linde Group.

Formed in 1920 by Edward Boughton, Willie Emmott and Denis Brock to import and sell American made components for military vehicles which had been left behind after the First World War. Later on they obtained a licence to manufacture and sell the Lockheed Hydraulic Braking System in Britain and Europe, leading to the formation of a subsidiary, the Lockheed Hydraulic Brake Company Ltd. Automotive Products, also known as AP, came to dominate the UK market in clutches and brakes. During the Second World War, AP manufactured aircraft and components for armaments. By the end of the 1950s the Aircraft Division was moved from Leamington to Speke airport, Liverpool, and was renamed Lockheed Precision Products. In 1986, AP was bought by British Belting and Asbestos (BBA). AP and its parent company experienced a difficult period in the early 1990s, which led to restructuring and, in 1995, the sale of AP to a management consortium known as AP Group.

Dowty Group began as the Aircraft Components Company in 1931, established by inventor George Herbert Dowty. The company developed innovative an innovative design for aircraft undercarriages, which was used by the Gloster Aircraft Company from 1934. The business was renamed Dowty Aviation in the following year and went public in 1936. In the lead-up and during the Second World War, demand was high and the business prospered, opening additional plants in Canada and the United States. Dowty Group continued its success in the postwar years, specialising in hydraulic and actuation systems, as well as turbine engine parts, advanced propellors and tubular systems. The company diversified into telecommunications and software. In 1992 Dowty Group was acquired by British engineering business TI Group.

Vickers-Armstrongs (Aviation) Ltd emerged from the reorganisation of Vickers (Aviation) Ltd and Supermarine Aviation Works (Vickers) Ltd in 1938. Within the new company, both the Vickers works and the Supermarine works continued to brand their products under their original names. The parent company, Vickers-Armstrongs Ltd, was formed by the merger of Vickers Limited and Sir W G Armstrong Whitworth & Company in 1927. Vickers Limited had established its Aviation Department in 1911. In 1928, the Aviation Department was reconstituted as Vickers (Aviation) Limited. Around the same time, Vickers (Aviation) Limited acquired the Supermarine Aviation Works, which built the Spitfire fighter plane, renaming them the Supermarine Aviation Works (Vickers) Ltd. In 1960 Vickers-Armstrong (Aircraft) Ltd was one of the companies involved in the formation of British Aircraft Corporation (BAC) formed as a result of the merger of Vickers-Armstrong (Aviation) Ltd, Bristol Aviation, English Electric and Hunting. The Vickers brand name was eventually dropped by BAC in 1965.