Metal Propellers Ltd was established by Henry Leitner and Dr Henry Watts, two engineers who had collaborated in designing a hollow steel aircraft propeller (an improvement on the wooden propellers which were then standard). They established a syndicate called the Metal Airscrew Co Ltd during the First World War, to carry out experimental research work; and this resulted in the production of the 'Leitner-Watts' propeller, which successfully passed official tests in 1917 and 1918, and flew successfully in 1920. The firm was subsequently established as a manufacturing company under the name of Metal Propellers Ltd, and opened its general offices and works at 74 Purley Way, Croydon, in 1925. The Directors included Viscount Elibank, Captain HH Balfour (later Under Secretary of State for Air, and eventually Lord Balfour) and Air Vice Marshal Sir Godfrey Paine. Major General Sir Sefton Brancker (Director of Civil Aviation at the Air Ministry) also had an interest.
The company supplied propellers for the R101 airship. These were apparently not the propellers fitted when the R101 crashed tragically in October 1930; but the disaster was nonetheless a severe setback for the company, as the dead included both Sir Godfrey Paine and Sir Sefton Brancker.
As well as propellers, the company manufactured other items in stainless steel, for a range of domestic and industrial uses; and it eventually evolved into a general engineering company, specialising in stainless steel. It later became associated with Saunders-Roe Ltd, flying-boat builders. In 1960, it acquired the neighbouring company in the Purley Way, the Standard Steel Co (1929) Ltd, structural engineers; and in 1962 it merged with LA Mitchell Ltd, chemical and industrial drying engineers of Manchester. It closed down in 1973.
Phyllis Devereux (b 1914) joined the firm in 1930 as a trainee technical assistant to Dr Watts, having been recruited from Lady Edridge School. She left the firm in 1934.