The investment is part of Nippon Steel’s commitment to invest $11 billion in the development of US Steel

Japanese steel corporation Nippon Steel will invest about $3 billion in upgrading the hot rolling mill at US Steel’s Mon Valley Works in Pennsylvania. This was reported by Reuters, citing Nikkei.

The investment is part of Nippon Steel’s broader commitment to invest $11 billion in the development of US Steel by 2028, following the completion of its acquisition of the American company in 2025.

The hot rolling equipment at Mon Valley, which is used to heat and roll steel slabs, has been in operation for about 90 years. The new state-of-the-art equipment is scheduled to be commissioned in the second half of 2029, which will allow the plant to produce much higher-quality steel.

In August, Nippon Steel raised its profit forecast for fiscal year 2026 on the back of higher earnings at US Steel and stable conditions in the global steel market.

More than a year ago, Nippon Steel completed its $14.9 billion acquisition of US Steel after 18 months of intense political and regulatory battles in Washington. Over the summer, about 100 specialists seconded from Japan worked on 260 initiatives to improve operations, introducing the company’s own technological know-how to increase production efficiency.

Nippon Steel expects the US market to grow steadily thanks to import tariffs and sustained demand. This could boost the profits of its subsidiary US Steel above current forecasts.

Earlier, Nippon Steel announced plans to double steel production in the US within 3-5 years. The Japanese steelmaker also intends to improve the American company’s product mix by offering advanced production technologies, such as high-performance electrical steel sheet, which is used, in particular, in electric vehicle motors.