331110 — Iron and Steel Mills and Ferroalloy Manufacturing
Description
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.
Exclusions & Cross-References
- 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; and
- Manufacturing fabricated structural metal products from concrete reinforcing bars and fabricated bar joists-
- are classified in U.S. Industry 332312, Fabricated Structural Metal Manufacturing.
Overview Facts
| NAICS Code | 331110 |
|---|---|
| Industry Title | Iron and Steel Mills and Ferroalloy Manufacturing |
| SBA Size Standard | 1,500 employees |
| U.S. Establishments | 359 (Census CBP, 2023) |
| IRS PBA Code | 331110 (exact match) |
| Sectors Hierarchy | Sector 31-33 → 331 → 3311 |
| Source / Verified | US Census 2022 NAICS Manual, Census CBP / 2026-06-28 |
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 3312 - Steel Works, Blast Furnaces (via SIC1987:3312→NAICS1997:331111→2002:331111→2007:331111→2012:331110→2017:331110→2022:331110)
- SIC 3313 - Electrometallurgical Products, Except Steel (via SIC1987:3313→NAICS1997:331112→2002:331112→2007:331112→2012:331110→2017:331110→2022:331110)
Suggested Product Service Codes (Advisory)
The following Product Service Codes (PSCs) are advisory suggestions aligned with this NAICS code. Note: NAICS and PSC codes map to different dimensions of procurement (industry vs. product/service). There is no official binding 1:1 crosswalk.
- PSC 4430 — Industrial Furnaces, Kilns, Lehrs, and Ovens
- PSC 9610 — Ores
- PSC 9630 — Additive Metal Materials
- PSC 9640 — Iron and Steel Primary and Semifinished Products
- PSC 9640 — Iron and Steel Primary and Semifinished Products
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Related Resources & Compliance Guides
Further regulatory reference links for NAICS code 331110:
- Sector 31-33 Directory Hub — List of related industries in the Manufacturing sector.
- SIC ↔ NAICS Crosswalk Tool — Look up mappings between legacy SIC codes and modern classifications.
- SBA Size Standards Guide — Complete rules and averaging periods for small business classifications.
- Calculating Annual Receipts Guide — Detailed worked example of revenue calculation rules.
- IRS Principal Business Activity Guide — How NAICS codes map to corporate and entity tax filings.
Related Industries in 3311
Frequently Asked Questions (FAQ)
Is 331110 a valid 2022 NAICS code?
NAICS 331110 is 'Iron and Steel Mills and Ferroalloy Manufacturing', a 2022 U.S. national industry under Sector 31-33 (Manufacturing); the SBA small-business size standard is 1,500 employees.
What is the SBA size standard for NAICS 331110?
The SBA small business size standard for NAICS 331110 is 1,500 employees (based on employees).
What is the legacy SIC code mapping for 331110?
NAICS code 331110 maps to the legacy 1987 SIC codes: 3312 - Steel Works, Blast Furnaces, 3313 - Electrometallurgical Products, Except Steel.