U.S. Iron and Steel Mills and Ferroalloy Manufacturing

1. Overview

North American Industry Classification System (NAICS) code 331110 covers U.S. establishments that reduce iron ore, make pig iron, convert iron into steel, melt steel, cast and roll steel into sheet, plate, bar, rod, strip, wire, pipe or tube, and manufacture electrometallurgical ferroalloys.[1] These are primary steel producers—plants that make steel from raw materials or scrap—not processors that merely roll, draw, or form purchased steel.

Public investors can access the industry through Nucor, Steel Dynamics, and Cleveland-Cliffs, plus foreign-listed Nippon Steel (which acquired U.S. Steel in 2025). Private investors can acquire regional minimills, specialty producers, ferroalloy operations, or stakes in new capacity projects—but should verify that an asset actually makes steel rather than merely processing or distributing purchased metal.

The central investment question is which steelmaking route and product mix will generate sustainable returns through the cycle. Returns depend on metal spread (selling price minus metallic input cost), plant utilization, product differentiation, vertical integration, trade protection, and environmental compliance—not simply on steel demand.

2. What it is and industry structure

There are two principal steelmaking routes. An integrated blast-furnace/basic-oxygen-furnace (BOF) mill converts iron ore into pig iron using coke and limestone, then refines the molten iron with scrap in an oxygen furnace. An electric-arc-furnace (EAF) mill, commonly called a minimill, uses electricity to melt ferrous scrap, direct-reduced iron (DRI), hot-briquetted iron, or pig iron. Molten steel from either route is alloyed, continuously cast into slabs, billets, or blooms, and rolled and finished into saleable shapes. Continuously cast steel represented 99.7% of U.S. output in 2025.[2]

The Department of Energy reports that EAFs now produce 70% of domestic steel and that remelting scrap in an EAF requires less than half the energy required to make steel from ore through the blast-furnace route.[3] Integrated mills can make demanding virgin-iron products and exploit captive ore, coke, and coal positions, but have high fixed costs, long campaigns, and expensive shutdowns. EAF mills can start and stop more readily and normally require less capital and fixed operating cost, but are more directly exposed to scrap prices and electricity costs.[4]

Ferroalloys—iron-bearing additions containing manganese, silicon, chromium, vanadium, tungsten, titanium, or molybdenum—change the chemistry and performance of the finished steel.[1] The classification is process-based: processors that merely roll, draw, or form purchased steel generally fall under NAICS 3312, not 331110.

Ownership is concentrated among a few large producers but includes many smaller specialty and regional operators. At the beginning of 2025, two companies operated integrated steel production at eight active locations, while 47 companies produced EAF steel at 102 minimills.[2] The leading operators are Nucor, Cleveland-Cliffs, Steel Dynamics, and U.S. Steel (now owned by Nippon Steel). U.S. Steel ceased being a separately traded U.S. public company when Nippon Steel completed its acquisition on June 18, 2025.[5][6]

3. How big it is

The U.S. Geological Survey estimates that the United States produced 82 million metric tons of raw steel in 2025, with sales value of approximately $149 billion and combined raw-steel capacity of about 105 million tons per year. Apparent consumption was 95 million tons, steel-mill-product imports were 24 million tons, exports were 7 million tons, and net import reliance was 13% of apparent consumption.[2]

These figures are from USGS Mineral Commodity Summaries 2026 and Census Bureau data.[2][7] The establishment count covers physical operating locations with payroll, not parent companies. The latest exact six-digit Census shipment figure retrieved was $118.8 billion for 2021, up 59.7% from $74.9 billion in 2020—a swing reflecting both volume recovery and steel-price inflation.[8][9]

A current four-firm concentration ratio, Herfindahl-Hirschman Index, public-versus-private share of output, or the portion of revenue attributable specifically to ferroalloys could not be established from available sources.

4. Investable universe

Public companies

The three primary U.S.-listed exposures differ meaningfully in steelmaking route, product mix, and operating model.

Company-level tonnage measures include internal transfers, downstream processing, and sometimes Canadian production, so they should not be used to manufacture precise market-share statistics against USGS U.S.-only totals.

Private and other exposures

• BlueScope Steel: Australian-listed parent of North Star BlueScope Steel, an EAF flat-roll producer in Ohio.
• Regional minimills and specialty producers: Numerous privately held operators serve regional markets, specialty steel grades, or ferroalloy production.
• Upstream exposure: Scrap processors, DRI/HBI producers, and iron-ore miners provide indirect steel exposure with different risk profiles.

An authoritative industry-wide private-company valuation multiple or recent private transaction median could not be established from available sources. Private investors must underwrite environmental liabilities, pension and retiree obligations, union contracts, power and freight arrangements, maintenance capital, customer qualifications, and the cost of surviving a low-utilization cycle.

5. How the money works

Steel profitability is governed primarily by the metal spread: realized selling price less the cost of metallic inputs. For EAF operators, ferrous scrap and scrap substitutes dominate variable cost. Steel Dynamics reports that metallic inputs normally represent 55%–65% of its steel-mill manufacturing costs. In 2025, its average selling price declined faster than scrap cost, reducing metal spread by 2% and steel-operations operating income by 10%. The segment reported $13.413 billion of net sales and $1.428 billion of operating income, implying an operating margin of approximately 10.6%.[10]

Integrated mills substitute exposure to iron ore, metallurgical coal, coke, natural gas, and ore-pellet costs for some scrap exposure. Cleveland-Cliffs estimates that one net ton of integrated raw steel ordinarily consumes approximately 1.4 net tons of iron-ore pellets or HBI equivalents, 0.3–0.4 net tons of coke, 0.3 net tons of scrap or substitutes, and 5–6 MMBtu of natural gas before rolling and finishing. Its EAFs require approximately 1.1 net tons of metallic input per net ton of steel.[11]

Utilization is the second major earnings lever. The industry carries large depreciation, maintenance, labor, and environmental costs even when production falls. Nucor's steel-mill utilization increased from 76% in 2024 to 83% in 2025, producing materially more tonnage over the same asset base.[4] Conversely, outages, idlings, or weak demand can cause unit costs to rise abruptly.

There is no defensible single "industry margin." Product mix, accounting, vertical integration, and timing of contract resets differ too much. Cleveland-Cliffs reported a negative 5% steelmaking gross margin in 2025, while Steel Dynamics' steel operations produced a positive margin as noted above.[10][11] Value-added coated sheet, electrical steel, specialty bar, and automotive-qualified products tend to command premiums and customer stickiness; commodity hot-rolled coil, rebar, and merchant bar are more exposed to spot prices and imports.

Working capital reinforces cyclicality. Mills and service centers accumulate expensive inventory when prices rise; subsequent destocking can reduce orders more sharply than end-user consumption. Freight, rail, and barge access also matter because ore, scrap, and finished steel are heavy, low-value-per-pound products.

6. Demand drivers

USGS estimates that construction represented 31% of U.S. net steel shipments by market classification in 2025; service centers and distributors represented 26%, automotive 15%, and converting and processing 11%, leaving 17% for other uses.[2]

• Construction: Nonresidential buildings, warehouses, data centers, and public structures drive demand for structural steel, rebar, sheet, and plate.
• Infrastructure: Grid and transmission investment, energy infrastructure, bridges, and highway projects supported by public funding programs.
• Automotive: Vehicle production consumes substantial flat-roll steel, though advanced high-strength grades compete with aluminum and composites on weight.
• Energy: Oil and gas drilling, pipelines, LNG projects, renewable energy structures, and power-generation equipment.
• Manufacturing reshoring: Semiconductor and battery plants, advanced manufacturing facilities, and regionalized supply chains.
• Distributor behavior: Service-center inventory building and destocking can temporarily dominate underlying end-market demand.

Nucor reported strong 2025 demand from infrastructure, data centers, energy, and advanced manufacturing, while automotive and residential construction were softer. Steel Dynamics similarly attributed demand to infrastructure funding, onshoring, and regionalized supply chains.[4][10]

The production mix is moving further toward EAFs, higher-quality scrap substitutes, and lower-carbon iron. Decarbonization pathways include natural-gas or hydrogen DRI, electric melting, furnace electrification, cleaner power, efficiency, and carbon capture. The Department of Energy identifies hydrogen DRI, iron electrolysis, electrified reheat furnaces, and carbon capture as priority technologies, but several remain dependent on lower costs and commercial-scale demonstration.[12]

7. Regulation

Trade policy materially affects pricing. As of April 2026, the United States applied a 50% Section 232 rate to articles made entirely or almost entirely of steel and a 25% rate to qualifying derivative articles.[13] Historical analysis by the U.S. International Trade Commission found that the earlier Section 232 steel measures reduced affected imports by 24%, raised U.S. steel-product prices by 2.4%, and increased domestic production by 1.9% on average over 2018–2021; they also raised downstream prices and reduced downstream production.[14] Tariffs therefore transfer economics toward mills but can weaken steel-consuming customers.

Environmental obligations are material and route-specific:

• Integrated mills: Emit hazardous metals and organics from sinter plants, blast furnaces, and basic-oxygen shops. EPA's amended hazardous-air-pollutant standards require maximum-achievable-control technology.[15]
• EAF mills: Avoid much of the blast-furnace carbon burden but generate particulate emissions and hazardous EAF dust and remain exposed to grid prices and emissions.

Nucor expects approximately $250 million of safety and environmental spending in 2026 and estimates environmental-compliance capital expenditures at existing facilities below $100 million annually in both 2026 and 2027.[4]

Labor is a meaningful constraint. More than 90% of Cleveland-Cliffs' hourly workforce is union-represented, and several major site agreements were scheduled for negotiation in 2026. The company identifies shortages of electricians and other experienced industrial workers. Work stoppages, wage escalation, retiree obligations, and loss of skilled operators can affect both cost and production continuity, particularly at integrated facilities.[11]

8. Competitive dynamics and consolidation

Global overcapacity is the largest external pricing threat. The OECD estimates global excess steelmaking capacity reached 640 million tonnes in 2025 and projects 745 million tonnes by 2028. Even if tariffs limit direct U.S. imports, displaced foreign steel can depress world prices, redirect trade through third countries, and provoke further trade actions.[16]

Domestic competition is segmented by product, route, and customer qualification. EAF sheet has been displacing integrated sheet in many applications, but automotive-qualified grades, electrical steel, and specialty products require demanding certifications and capital. Scale improves scrap purchasing, energy efficiency, logistics, and the ability to serve large customers with consistent quality.

Consolidation has been meaningful: Nucor assembled its position through acquisitions, Cleveland-Cliffs combined legacy integrated assets with AK Steel and ArcelorMittal USA operations, and Nippon Steel acquired U.S. Steel in 2025. Further consolidation may be constrained by antitrust review, particularly for transactions combining integrated capacity serving automotive customers.

Substitution is product-specific. Aluminum competes in vehicles and packaging; engineered wood and concrete compete in buildings; composites and plastics compete in transportation and consumer products. Advanced high-strength steel partly counters substitution by reducing weight without abandoning steel's established forming, repair, and recycling infrastructure.

9. Risks

• Metal-spread compression: Input prices (scrap, ore, energy) can rise before selling prices reset, or selling prices can fall before input costs decline.
• Cyclicality: Construction, automotive, and industrial spending can decline together, amplified by distributor destocking.
• Utilization volatility: High fixed costs mean low utilization can cause severe margin degradation; conversely, capacity additions can overshoot demand.
• Global overcapacity: Excess capacity, currently estimated at 640 million tonnes, depresses world prices and encourages trade circumvention.[16]
• Trade-policy reversal: Section 232 tariffs help domestic mills but are politically and legally changeable through executive action, exemptions, or litigation.
• Environmental compliance: Route-specific emissions rules, hazardous-waste obligations, and decarbonization mandates require ongoing capital spending.[15]
• Labor constraints: Union negotiations, skilled-worker shortages, and legacy pension/retiree obligations, particularly at integrated mills.[11]
• Customer concentration: Large automotive OEMs, construction firms, and distributors can exert bargaining power.
• Inventory losses: High-cost metal bought near a market peak may be sold after prices fall.
• Technology transition: Investments in hydrogen DRI, carbon capture, or other decarbonization technologies may not achieve expected returns or timelines.[12]
• Substitution: Aluminum, composites, engineered wood, and concrete compete in various end markets.

10. How to invest and outlook

Public investors should decide whether they want EAF-focused exposure with downstream integration (Nucor, Steel Dynamics) or integrated ore-to-steel exposure with automotive concentration and higher operating leverage (Cleveland-Cliffs). Nippon Steel provides access to the former U.S. Steel operations through a foreign listing. Valuation should use mid-cycle earnings rather than peak metal spreads. Relevant measures include enterprise value to EBITDA, free-cash-flow yield, balance-sheet leverage, replacement cost per ton of capacity, and metal-spread sensitivity.

Private investors should focus diligence on metallic-input formulas, customer contracts and qualifications, union agreements, environmental liabilities, maintenance capital requirements, power and freight arrangements, and the cost of surviving a low-utilization cycle. Attractive targets are more likely to have differentiated products, flexible scrap sourcing, customer stickiness through qualification, and disciplined working capital than simply large nominal capacity.

Forward-looking judgment: The demand outlook is supported by infrastructure spending, manufacturing reshoring, data-center construction, and energy investment. Margin prospects are more uncertain: global overcapacity at 640 million tonnes and rising, volatile input costs, and potential trade-policy changes can overwhelm demand growth.[16] The EAF route's lower capital intensity, energy advantage, and restart flexibility position it favorably for the decarbonization transition, but all producers face the challenge of earning adequate returns through the cycle. The best-positioned operators should be those that can pass through input costs quickly, maintain high utilization, and sell qualified products where quality, service, and certification matter more than the lowest spot price.

Sources

1. U.S. Census Bureau, 2022 NAICS Manual, 2022, https://www.census.gov/naics/?details=33&input=33&year=2022
2. U.S. Geological Survey, Mineral Commodity Summaries 2026: Iron and Steel, 2026, https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-iron-steel.pdf
3. U.S. Department of Energy, Iron and Steel Manufacturing, 2026, https://www.energy.gov/cmei/ito/iron-and-steel-manufacturing
4. Nucor Corporation, 2025 Form 10-K, 2026, https://www.sec.gov/Archives/edgar/data/73309/000119312526071575/nue-20251231.htm
5. United States Steel Corporation, Form 8-K: Completion of Acquisition, 2025, https://www.sec.gov/Archives/edgar/data/1163302/000110465925062586/tm2518973d1_8k.htm
6. Nippon Steel Corporation, Completion of U.S. Steel Acquisition, 2025, https://www.nipponsteel.com/en/newsroom/news/2025/20250618_100.html
7. U.S. Census Bureau, NAICS 331110 Industry Profile, 2023, https://data.census.gov/profile/331110_-_Iron_and_steel_mills_and_ferroalloy_manufacturing?codeset=naics~331110
8. U.S. Census Bureau, 2021 Annual Survey of Manufactures, 2022, https://www.census.gov/newsroom/press-releases/2022/annual-survey-of-manufactures.html
9. U.S. Census Bureau, 2020 Annual Survey of Manufactures, 2021, https://www.census.gov/newsroom/press-releases/2021/2020-annual-survey-of-manufactures-data.html
10. Steel Dynamics Inc., 2025 Form 10-K, 2026, https://www.sec.gov/Archives/edgar/data/1022671/000110465926021395/stld-20251231x10k.htm
11. Cleveland-Cliffs Inc., 2025 Form 10-K, 2026, https://www.sec.gov/Archives/edgar/data/764065/000076406526000025/clf-20251231.htm
12. U.S. Department of Energy, Industrial Decarbonization Roadmap, 2022, https://www.energy.gov/sites/default/files/2022-09/Industrial%20Decarbonization%20Roadmap.pdf
13. U.S. Department of Commerce, Section 232 Tariff Summary, 2026, https://www.trade.gov/press-release/what-they-are-saying-president-trump-strengthens-us-steel-aluminum-and-copper
14. U.S. International Trade Commission, Economic Impact of Section 232 and 301 Tariff Actions, 2023, https://www.usitc.gov/press_room/news_release/2023/er0315_63679.htm
15. U.S. Environmental Protection Agency, Integrated Iron and Steel Manufacturing NESHAP, 2025, https://www.epa.gov/stationary-sources-air-pollution/integrated-iron-and-steel-manufacturing-national-emission
16. Organisation for Economic Co-operation and Development, OECD Steel Outlook 2026, 2026, https://www.oecd.org/en/publications/2026/06/oecd-steel-outlook-2026_a79fb861/full-report/international-efforts-to-address-the-steel-crisis-are-intensifying_b6ca4947.html