The Tariff Wall Has a Hole in It, and It's in Fontana
From the Editors of The Citrus Belt Review • 2 min read
Citrus Belt Review: The national steel story this week is a victory lap. Census data compiled by the American Iron and Steel Institute shows imports down roughly 30% year to date — 6.97 million net tons through April against 9.89 million a year earlier — while domestic raw steel production is up 6.8%. The Steel Manufacturers Association says Section 232 is working as intended. For most of the country's steel towns, it is.
Fontana is not most steel towns. California Steel Industries, the West's leading flat-rolled producer, does not make steel. It converts it. The mill that rose from Kaiser Steel's rolling lines in 1984 reheats imported slab — sourced primarily from Brazil and Mexico — and rolls it into the coil, galvanized sheet, and pipe that West Coast construction and energy markets run on. By the company's own filings, that's roughly 1.5 million tons of finished sheet a year, about 900 direct jobs, and an estimated 6,500 more across its supply chain.
The mechanism matters because slab is not produced for sale anywhere in the western United States. A tariff on slab is not protection for Fontana; it is a tax on Fontana's feedstock. CSI made that argument in 2018, and Washington split the difference: Brazil got a zero-tariff quota covering 3.5 million tons of semi-finished steel a year. The carve-out held until March 2025, when the administration ended quotas and exclusions; in June, the rate doubled to 50%. Everything since has confirmed slab's place at the top of the structure. April's restructuring made the regime tiered rather than blanket — lower rates for machinery, exemptions for low-metal-content goods — but semi-finished steel stayed at 50% of full customs value. And February's Supreme Court ruling, which struck down the IEEPA tariffs wholesale, left Section 232 standing. The tariff wall has been narrowed twice this year. Slab is still inside it.
Who pays the 50% is the part national coverage skips. Brazilian mills, dependent on American buyers, cut prices to keep the business — slab shipments to the U.S. rose 12% last year, to 4.83 million tons. Importers now pay 50% of a lower price, and the burden splits between Brazilian mill margins and West Coast buyers. The residual is public: Nucor, CSI's majority owner since 2022, publishes a weekly hot-rolled coil spot price and quotes CSI separately, consistently $50 to $60 a ton above its domestic mills. That spread is the tariff's West Coast cost, printed on a price sheet every Monday.
The structural signal sits in Alabama. AM/NS Calvert — the country's other marquee slab converter, built on the same melt-abroad, roll-here model as Fontana — fired up its own electric arc furnace last June and signed a seven-year domestic slab supply deal. It stopped being a converter. Nucor's Fontana commitments cut partly the other way: a $370 million galvanizing line announced in 2022 adds 400,000 tons of finishing capacity. But finishing investment answers a different question than where the steel gets melted. The industry's direction of travel is to melt domestically. Fontana still doesn't.
The corridor reading is the one this publication keeps arriving at: the IE is an intake valve for the West Coast economy, and policy built around production geographies lands here as cost. Watch the slab tonnage through the San Pedro ports, the Nucor-CSI spread, and whether Nucor moves to feed Fontana from its own furnaces. The national story is about what stopped coming in. The Fontana story is about what still has to.