2022 NAICS national industry in sector 31-33 Manufacturing
331110 Iron and Steel Mills and Ferroalloy Manufacturing
NAICS 331110 is the US industry code for iron and steel mills and ferroalloy manufacturing. It covers establishments primarily engaged in one or more of the following: (1) direct reduction of iron ore; (2) manufacturing pig iron in molten or solid form; (3) converting pig iron into steel; (4) making steel; (5) making steel and manufacturing shapes (e.g., bar, plate, rod, sheet, strip, wire); (6) making steel and forming pipe and tube; and (7) manufacturing electrometallurgical ferroalloys.
- Code
- 331110 (2022 NAICS)
- Title
- Iron and Steel Mills and Ferroalloy Manufacturing
- Part of
- Iron and Steel Mills and Ferroalloy Manufacturing
- SBA small business limit
- Up to 1,500 employees
- Closest UK SIC
- 24100 (details)
Changes coming. The NAICS 2027 revision applies to data from 1 January 2027, and SBA proposed new size standards on 20 August 2026. The values on this page are the ones in force today; we update this page when the official files change.
Official definition
This industry comprises establishments primarily engaged in one or more of the following: (1) direct reduction of iron ore; (2) manufacturing pig iron in molten or solid form; (3) converting pig iron into steel; (4) making steel; (5) making steel and manufacturing shapes (e.g., bar, plate, rod, sheet, strip, wire); (6) making steel and forming pipe and tube; and (7) manufacturing electrometallurgical ferroalloys. Ferroalloys add critical elements, such as silicon and manganese for carbon steel and chromium, vanadium, tungsten, titanium, and molybdenum for low- and high-alloy metals. Ferroalloys include iron-rich alloys and more pure forms of elements added during the steel manufacturing process that alter or improve the characteristics of the metal.
When to use a different code
Census classifies these close-sounding activities somewhere else. Businesses mainly engaged in:
- Operating coke ovens are classified in U.S. Industry 324199, All Other Petroleum and Coal Products Manufacturing.
- Manufacturing nonferrous superalloys, such as cobalt or nickel-based superalloys are classified in U.S. Industry 331492, Secondary Smelting, Refining, and Alloying of Nonferrous Metal (except Copper and Aluminum).
- Manufacturing concrete reinforcing bar by rolling and drawing steel from purchased steel are classified in U.S. Industry 331221, Rolled Steel Shape Manufacturing.
- Manufacturing fabricated structural metal products from concrete reinforcing bars and fabricated bar joists are classified in U.S. Industry 332312, Fabricated Structural Metal Manufacturing.
Activities listed under 331110
The Census index assigns these 91 activities to this code. If your business matches one, this is your code.
- Armor plate made in iron and steel mills
- Axles, rolled or forged, made in iron and steel mills
- Balls, steel, made in iron and steel mills
- Bars, concrete reinforcing (rebar) made in steel mills
- Bars, iron, made in iron and steel mills
- Bars, steel, made in iron and steel mills
- Billets, steel, made in iron and steel mills
- Blackplate made in iron and steel mills
- Blast furnaces
- Blooms, steel, made in iron and steel mills
- Car wheels, rolled steel, made in iron and steel mills
- Coke oven products made in iron and steel mills
- Concrete reinforcing bar (rebar) made in iron and steel mills
- Direct reduction of iron ore
- Electrometallurgical ferroalloy manufacturing
- Electrometallurgical steel manufacturing
- Fence posts, iron or steel, made in iron and steel mills
- Ferroalloys manufacturing
- Ferrochromium manufacturing
- Ferromanganese manufacturing
- Ferromolybdenum manufacturing
- Ferrophosphorus manufacturing
- Ferrosilicon manufacturing
- Ferrotitanium manufacturing
- Ferrotungsten manufacturing
- Ferrovanadium manufacturing
- Flakes, iron or steel, made in iron and steel mills
- Flats, iron or steel, made in iron and steel mills
- Forgings, iron or steel, made in iron and steel mills
- Frogs, iron or steel, made in iron and steel mills
- Galvanizing metals and metal formed products made in iron and steel mills
- Gun forgings made in iron and steel mills
- High percentage nonferrous alloying elements (i.e., ferroalloys) manufacturing
- Hoops made in iron and steel mills
- Hoops, galvanized, made in iron and steel mills
- Hot-rolling iron or steel products in iron and steel mills
- Ingot made in iron and steel mills
- Iron ore recovery from open hearth slag
- Iron sinter made in iron and steel mills
- Iron, pig, manufacturing
- Manganese metal ferroalloys manufacturing
- Mesh, wire, made in iron and steel mills
- Mini-mills, steel
- Molybdenum silicon ferroalloys manufacturing
- Nut rods, iron or steel, made in iron and steel mills
- Paste, iron or steel, made in iron and steel mills
- Pig iron manufacturing
- Pilings, iron or steel plain sheet, made in iron and steel mills
- Pipe, iron or steel, made in iron and steel mills
- Plate, iron or steel, made in iron and steel mills
- Powder, iron or steel, made in iron and steel mills
- Rail joints and fastenings made in iron and steel mills
- Railroad crossings, iron or steel, made in iron and steel mills
- Rails rerolled or renewed in iron and steel mills
- Rails, iron or steel, made in iron and steel mills
- Rods, iron or steel, made in iron and steel mills
- Rounds, tube, steel, made in iron and steel mills
- Sheet pilings, plain, iron or steel, made in iron and steel mills
- Sheets, steel, made in iron and steel mills
- Shell slugs, steel, made in iron and steel mills
- Silicomanganese ferroalloys manufacturing
- Skelp, iron or steel, made in iron and steel mills
- Slab, steel, made in iron and steel mills
- Spiegeleisen ferroalloys manufacturing
- Spike rods made in iron and steel mills
- Sponge iron
- Stainless steel made in iron and steel mills
- Steel balls made in iron and steel mills
- Steel manufacturing
- Steel mill products (e.g., bar, plate, rod, sheet, structural shapes) manufacturing
- Steel mills
- Steel, from pig iron, manufacturing
- Strip, galvanized iron or steel, made in iron and steel mills
- Strip, iron or steel, made in iron and steel mills
- Structural shapes, iron or steel, made in iron and steel mills
- Superalloys, iron or steel, manufacturing
- Template, made in iron and steel mills, manufacturing
- Terneplate made in iron and steel mills
- Ternes, iron or steel, long or short, made in iron and steel mills
- Tie plates, iron or steel, made in iron and steel mills
- Tin-free steel made in iron and steel mills
- Tinplate made in iron and steel mills
- Tool steel made in iron and steel mills
- Tube rounds, iron or steel, made in iron and steel mills
- Tube, iron or steel, made in iron and steel mills
- Tubing, seamless steel, made in iron and steel mills
- Tubing, wrought iron or steel, made in iron and steel mills
- Well casings, iron or steel, made in iron and steel mills
- Wheels, car and locomotive, iron or steel, made in iron and steel mills
- Wire products, iron or steel, made in iron and steel mills
- Wrought iron or steel pipe and tubing made in iron and steel mills
SBA size standard for 331110
To count as a small business for SBA loans and federal contracts under NAICS 331110, your business (including affiliates) must not exceed 1,500 employees. Check your business.
Source: SBA table of size standards, effective March 17, 2023.
Closest UK SIC 2007 codes
There is no official one-to-one link between NAICS and UK SIC. These codes share the same international class (ISIC Rev. 4: 2410), so treat them as a starting point and check the definition.
Built from Census concordances 2022→2017 NAICS and 2017 NAICS→ISIC Rev. 4.
Data last changed November 14, 2026. How this page is built.