Century Aluminum boosts domestic output 10% as tariffs drive expansion

A $50 million investment at a South Carolina smelter is adding 10% to America's primary aluminum capacity, the clearest sign yet that Trump-era tariffs are reshaping domestic metals production.

Century Aluminum Co. expanded its Mt. Holly smelter in Goose Creek, South Carolina, boosting total U.S. domestic primary aluminum output by 10% and adding hundreds of jobs as Section 232 tariffs with no exemptions reshore production from overseas competitors.

"President Trump's Section 232 program with no exceptions and no exemptions shows what is possible when our leaders create the conditions necessary for long-term investment in American aluminum production," Jesse Gary, chief executive officer of Century Aluminum, said at the July 27 ribbon-cutting ceremony.

The $50 million expansion grows the Mt. Holly workforce to more than 600 employees. Century Aluminum, the single largest U.S. primary aluminum producer, now operates three smelters across Kentucky and South Carolina. Commerce Secretary Howard Lutnick, Senior Counselor to President Trump Dr. Peter Navarro and South Carolina Attorney General Alan Wilson joined the event.

The expansion signals that tariff-protected domestic smelters can compete against a global market where China produces more than half of the world's 70 million metric tons of annual aluminum output. With the Section 232 program barring import exemptions, U.S. producers face less competition from duty-free Canadian and European metal — a dynamic that could lift domestic aluminum prices and attract further investment into idled capacity.

The Mt. Holly ramp-up marks the first major capacity addition since the Trump administration tightened Section 232 enforcement in early 2025, eliminating country-specific exemptions that had previously allowed roughly 2 million metric tons of duty-free aluminum imports annually. The original 10% tariff, imposed in March 2018 under Section 232 of the Trade Expansion Act, was raised to 25% in 2020 and maintained under the current administration.

The U.S. currently produces about 800,000 metric tons of primary aluminum annually, down from a peak of 5.1 million metric tons in 2000, according to the Aluminum Association. The Mt. Holly expansion adds roughly 80,000 metric tons of annual capacity, partially reversing a two-decade decline that saw 15 domestic smelters close or idle.

"President Trump knows that American strength depends on a strong domestic aluminum industry," Lutnick said. "Century Aluminum's $50 million investment will increase American aluminum production by 10% and further cement South Carolina as a leader in American manufacturing."

The expansion comes as aluminum prices on the London Metal Exchange trade near $2,400 per metric ton, supported by demand from the automotive and construction sectors and constrained global supply. The U.S. Midwest premium — the surcharge over LME prices paid by domestic buyers — has widened as tariff-restricted imports tighten availability.

For Century Aluminum, the Mt. Holly expansion provides a template for potential reactivation of idled capacity elsewhere. The company's Hawesville, Kentucky smelter, idled in 2022 amid high power costs, could require similar policy certainty and power pricing agreements to restart. Century's Ravenswood, West Virginia smelter has been idled since 2009.

"This investment in expanded domestic aluminum production embodies President Trump's vision of a new Golden Age for American manufacturing," Navarro said.

The broader implications extend beyond Century. Alcoa Corp., the largest U.S.-based aluminum producer, operates three smelters in the U.S. with combined capacity of roughly 600,000 metric tons per year. Any further tariff-driven capacity additions across the industry could reduce the U.S.'s reliance on imports, which currently meet about 60% of domestic aluminum demand.

This article is for informational purposes only and does not constitute investment advice.