[6] In 1919, Parker's truck slid over a cliff, causing the company to lose its entire inventory and forcing the founder to return to his previous job.

For his flight across the Atlantic Ocean, Charles Lindbergh requested Parker parts be used in the construction of his aircraft the Spirit of St.

[9] During World War II, Parker experienced a boom in business as the U.S. Air Force's primary supplier of valves and fluid connectors.

After Arthur Parker's death in 1945[10] and the end of the war, the company neared bankruptcy due to the sudden drop in demand.

By 1979, Parker Hannifin employed 20,000 people in 100 plants, selling 90,000 items for machinery, airplanes, cars and construction equipment to 60,000 customers.

By 2008, Parker Hannifin Mexico would come to operate 11 plants in the country, seven of which made parts exclusively for the U.S. market.

[7] The company won $2 billion in contracts to build fuel and hydraulic systems for Airbus A350 airliners in 2008[23] Two years later, its products were used in repairing the Deepwater Horizon oil rig.

[30] In July 2022, after making commitments to the UK government including increasing research and development spending in Britain, the Secretary of State for Business, Energy and Industrial Strategy approved the takeover without being referred for a full Competition and Markets Authority investigation.

[32] In May 2022, it was announced Parker Hannifin has sold its aircraft wheel and brake division to the Bloomfield-headquartered aerospace company, Kaman Corporation for US$440 million.

[36] The company has had contracts to contribute parts and maintenance for machinery produced by Airbus,[37] Rolls-Royce, Commercial Aircraft Corporation of China as well as other manufacturers.

[36] In 2012, the company partnered with General Electric to form a 50–50 joint venture, Advanced Atomization Technologies, for producing fuel nozzles for commercial aircraft engines.

[42][43] In 2004, a Los Angeles jury ordered Parker Hannifin to pay US$43 million to the plaintiff families of the 1997 SilkAir Flight 185 crash in Indonesia.

The Indonesian National Transportation Safety Committee (NTSC) could not determine the cause of the crash due to the near total lack of physical evidence because of the complete destruction;[44] The US National Transportation Safety Board (NTSB), however disagreed, and concluded that the crash was caused, possibly intentionally, by the pilot.

The firm argued that the components they supplied were not at fault, citing that the product has one of the safest records in its class, but the FAA directive went through regardless.

This followed an incident two days earlier on January 16, in which the propulsion system experienced a fueldraulic failure prior to a conventional takeoff.