Hays Army Ammunition Plant was an , 1,650-employee foundry established in 1942 in the Hays neighborhood of

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

. At first it produced shells and breechblocks for the Navy. Though owned by the Army, the plant was operated by the Mesta Machine Company on behalf of the

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. The plant was operated by the Mullins Manufacturing Company during the

Korean War {{Infobox military conflict , conflict = Korean War , partof = the Cold War and the Korean conflict , image = Korean War Montage 2.png , image_size = 300px , caption = Clockwise from top:{ ...

and by the Levinson Steel Company during the

Vietnam War The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...

. For the Army it produced 105 mm shells, 250,000 of these per month throughout 1968. It was the only Army plant with cold extrusion capability. Manufacturing ceased in May 1970 and the plant was mothballed in June 1971. The 1982 value of the complex was $69 million. The plant was placed on standby in 1991 and donated for redevelopment in 1993. It is now used as an industrial site.

Headstamp

The headstamp and manufacturer code for Hays Army Ammunition Plant is HYAAP.

References

External links

* Industrial buildings and structures in Pittsburgh United States Army arsenals United States Army arsenals during World War II Historic American Engineering Record in Pennsylvania Industrial buildings completed in 1942 1942 establishments in Pennsylvania {{Pittsburgh-stub