US steel mill output fell by 115,000 tons — a 6.1% week-on-week drop — for the week ending Sept. 19, 2026, according to the Washington-based American Iron and Steel Institute (AISI).

The mid-September decline interrupted a production run that had reached 1.9 million tons of raw steel in the week ending Sept. 12. A week later, melt shops turned out 1.785 million tons. Mill capacity utilization tracked the same trajectory, sliding from 82.3% to 78.4%.

By the week ending Sept. 26, AISI recorded a 3.4% rebound to 1.845 million tons — recovering most, but not all, of the lost ground. Year-to-date production through Sept. 26 now stands at more than 70.1 million tons, up 5.3% from the 66.6 million tons made during the first nine months of 2025. Mills have run at an average 79.1% capacity rate year-to-date, per AISI.

What did satellite tracking add?

Navigate Commodities, which uses satellite imaging to track mill activity and bulk raw-material shipments globally, calculated a sharper two-week decline in operating capacity.

For the week ending Sept. 27, 2026, Navigate put US steel furnace utilization at 63.5% — down from 69.8% just two weeks earlier, a drop of 6.3 percentage points. The firm's independent tracking confirmed the mid-September dip that AISI had also reported.

How did technology and regions split?

Navigate's melt-shop breakdown for late September shows where the pressure landed. Electric arc furnace (EAF) mills — the dominant scrap-consuming segment — operated at 66.7% of capacity, down from 73.4% a week earlier. Blast furnace/basic oxygen furnace (BF/BOF) mills, which consume iron ore and metallurgical coal, ran at 54.5%, down from 58.9%.

Regionally, mills in the EAF-heavy US South outperformed at 79.7% of capacity for the week ending Sept. 27. The Great Lakes region — home to a mix of EAF and BOF capacity — ran at just 47.6%. The 32-percentage-point spread between the two markets shows how scrap-fed EAFs continue to set the US operating tempo.

What's happening with ferrous scrap?

Strong-to-steady 2026 demand from EAF producers for recycled steel has placed a high floor under ferrous scrap pricing, although price spikes have not materialized. For overseas buyers, cheap Chinese billet often displaces scrap-fed melt shop production.

Atilla Widnell, managing director of Navigate Commodities, warned in a mid-September LinkedIn post that a competing factor could shrink that alternative.

"Higher bunker fuel costs are capping/restricting China's geographical steel export reach," Widnell wrote. He added that the ripple effects could ultimately lower iron ore consumption in China and globally.

The implication for US recyclers is direct: the ferrous scrap floor depends on whether Chinese billet keeps undercutting overseas EAF economics, or whether bunker-driven logistics costs restore scrap's competitive position at longer shipping routes.

What milestone comes next?

AISI's weekly capacity utilization figure for the week ending Oct. 3, 2026 will be the next data point that decides whether September's dip was a one-week pullback or the start of a Q4 demand contraction. Navigate Commodities' regional and technology-mix update will follow in the same reporting window.