NAICS Code 331 — Primary Metal Manufacturing

Subsector in the official 2022 North American Industry Classification System (U.S. Census Bureau). It contains 5 direct sub-codes.

Code	331
Title	Primary Metal Manufacturing
Level	Subsector (3-digit)
Edition	NAICS 2022 edition

Official definition (2022 NAICS)

Industries in the Primary Metal Manufacturing subsector smelt and/or refine ferrous and nonferrous metals from ore, pig, or scrap, using electrometallurgical and other process metallurgical techniques. Establishments in this subsector also manufacture metal alloys and superalloys by introducing other chemical elements to pure metals. The output of smelting and refining, usually in ingot form, is used in rolling, drawing, and extruding operations to make sheet, strip, bar, rod, or wire, and in molten form to make castings and other basic metal products.

Primary manufacturing of ferrous and nonferrous metals begins with ore or concentrate as the primary input. Establishments manufacturing primary metals from ore and/or concentrate remain classified in the primary smelting, primary refining, or iron and steel mill industries regardless of the form of their output. Establishments primarily engaged in secondary smelting and/or secondary refining recover ferrous and nonferrous metals from scrap and/or dross. The output of the secondary smelting and/or secondary refining industries is limited to shapes such as ingot or billet that will be further processed. Recovery of metals from scrap often occurs in establishments that are primarily engaged in activities, such as rolling, drawing, extruding, or similar processes.

Excluded from the Primary Metal Manufacturing subsector are establishments primarily engaged in manufacturing ferrous and nonferrous forgings (except ferrous forgings made in steel mills) and stampings. Although forging, stamping, and casting are all methods used to make metal shapes, forging and stamping do not use molten metals and are included in Subsector 332, Fabricated Metal Product Manufacturing. Establishments primarily engaged in operating coke ovens are classified in Industry 32419, Other Petroleum and Coal Products Manufacturing.

Where 331 sits in the hierarchy

Level	Code	Title
Sector	31-33	Manufacturing
Subsector	331	Primary Metal Manufacturing

Codes under 331

Code	Title
3311	Iron and Steel Mills and Ferroalloy Manufacturing
3312	Steel Product Manufacturing from Purchased Steel
3313	Alumina and Aluminum Production and Processing
3314	Nonferrous Metal (except Aluminum) Production and Processing
3315	Foundries

Related Subsector codes

• 311 — Food Manufacturing
• 312 — Beverage and Tobacco Product Manufacturing
• 313 — Textile Mills
• 314 — Textile Product Mills
• 315 — Apparel Manufacturing
• 316 — Leather and Allied Product Manufacturing
• 321 — Wood Product Manufacturing
• 322 — Paper Manufacturing
• 323 — Printing and Related Support Activities
• 324 — Petroleum and Coal Products Manufacturing
• 325 — Chemical Manufacturing
• 326 — Plastics and Rubber Products Manufacturing

Data: official 2022 NAICS structure, descriptions and Census concordances, U.S. Census Bureau — U.S. government works in the public domain (17 U.S.C. §105). Suggested reference, not an official determination.