General Steel Industries

General Steel Industries, Inc. (GSI) was an American steel company founded as General Steel Castings Corporation in 1928. The company's first headquarters were in Eddystone, Pennsylvania and, prior to completing its own modern steel foundry in 1930, acquired the operations of the Commonwealth Steel Company, a critical supplier to the rail industry.

An acquisition program to diversify from its core steel castings business of manufacturing large steel castings was initiated in the late 1950s and resulted in six divisions and one subsidiary by 1971. The broader business portfolio allowed GSI to close the Castings Division, the company's only business prior to diversification, in 1973.

In 1974, GSI was operating 19 plants across the United States and internationally and continued operating as an independent company until it was acquired by Lukens Steel in 1981.