Harrisburg, PA (AP) – U.S. Steel said it will resume making steel slabs at its Granite City Works plant in Illinois as demand rebounds.

The company shut down the last blast furnace there in 2023, and it even moved to wind down its steel processing mill there in September.

However, it reversed its stance on the processing mill, under pressure from the White House, and now says it is going a step further by resuming steel making by reopening the blast furnace it idled two years ago amid strikes by the United Auto Workers.

U.S. Steel on Thursday cited “customer demand” in beginning the process of restarting a blast furnace at the plant in Southern Illinois, just across the Mississippi River from St. Louis.

“After several months of carefully analyzing customer demand, we made the decision to restart a blast furnace,” CEO David Burritt said a statement. “Steel remains a highly competitive and highly cyclical industry, but we are confident in our ability to safely and profitably operate the mill to meet 2026 demand.”

The Pittsburgh company expects to resume steel production in the first half of next year after it hires and trains workers and gets equipment in safe working order. It will need to hire 400 of the 500 workers necessary to operate the plant, the company said.

Currently, there are 12 operating blast furnaces in the U.S., the American Iron and Steel Institute said, down from about 140 in the 1970s before foreign competition devastated the American steel industry. Nobody in the U.S. has opened a new blast furnace in decades.

But economic conditions in the industry have improved the last few years.

Analysts say a robust U.S. steel market has been strengthened by tariffs under President Donald Trump and former President Joe Biden.

In addition, rebounding automaking and construction are helping, the institute said.

The institute reported that domestic steel mills in October shipped 7.7 million net tons, a 9% percent increase over the same month a year ago. Year-to-date shipments through October were up 5% over the same period in 2024, it said.

The decision by U.S. Steel, comes less than six months after Japan-based Nippon Steel sealed a deal with Trump to buy the iconic American steelmaker for $14.9 billion.

To resolve national security objections to the acquisition, Nippon Steel agreed to give the federal government a say in certain company decisions involving domestic steel production, including over closing or idling U.S. Steel’s plants.

It also pledged to invest some $14 billion in steel production in the U.S., including building a new electric furnace.

Under the national security agreement, protections expire in 2027 for Granite City Works, but last until 2035 for U.S. Steel’s other facilities.

Granite City Works makes rolls of sheet steel for the construction, container, pipe and automotive industries.

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This story has been corrected to show that the last blast furnace at Granite City closed two years ago, not three.

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