NAICS 3 Digit Subsector Code 331

Subsector 331

NAICS Subsector Code 331 – Primary Metal Manufacturing

Definition of NAICS 3 Digit Subsector Code 331: 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.

Three Digit Subsector Breakdown for the North American Industry Classification System

NAICS codes are broken down by digit. The broadest description starts with the 2 digit sector codes. The 3 digit subsector codes are more specific, then the 4 digit industry group, 5 digit industry, and the most specific is the 6 digit NAICS code. If NAICS Subsector 331 does not describe the industry of the business in question, then select the largest applicable code below. From there, follow the progression of smaller digits to the larger digits in order to obtain the most specific 6 digit classification.

  • Sector 31-33: Manufacturing
    • Subsector 331: Primary Metal Manufacturing
      • Industry Group 3311: Iron and Steel Mills and Ferroalloy Manufacturing
        • Industry 33111: Iron and Steel Mills and Ferroalloy Manufacturing
          • 6 Digit Code(s) NAICS 331110: Iron and Steel Mills and Ferroalloy Manufacturing
      • Industry Group 3312: Steel Product Manufacturing from Purchased Steel
        • Industry 33121: Iron and Steel Pipe and Tube Manufacturing from Purchased Steel
          • 6 Digit Code(s) NAICS 331210: Iron and Steel Pipe and Tube Manufacturing from Purchased Steel
        • Industry 33122: Rolling and Drawing of Purchased Steel
          • 6 Digit Code(s) NAICS 331221: Rolled Steel Shape Manufacturing
          • 6 Digit Code(s) NAICS 331222: Steel Wire Drawing
      • Industry Group 3313: Alumina and Aluminum Production and Processing
        • Industry 33131: Alumina and Aluminum Production and Processing
          • 6 Digit Code(s) NAICS 331313: Alumina Refining and Primary Aluminum Production
          • 6 Digit Code(s) NAICS 331314: Secondary Smelting and Alloying of Aluminum
          • 6 Digit Code(s) NAICS 331315: Aluminum Sheet, Plate, and Foil Manufacturing
          • 6 Digit Code(s) NAICS 331318: Other Aluminum Rolling, Drawing, and Extruding
      • Industry Group 3314: Nonferrous Metal (except Aluminum) Production and Processing
        • Industry 33141: Nonferrous Metal (except Aluminum) Smelting and Refining
          • 6 Digit Code(s) NAICS 331410: Nonferrous Metal (except Aluminum) Smelting and Refining
        • Industry 33142: Copper Rolling, Drawing, Extruding, and Alloying
          • 6 Digit Code(s) NAICS 331420: Copper Rolling, Drawing, Extruding, and Alloying
        • Industry 33149: Nonferrous Metal (except Copper and Aluminum) Rolling, Drawing, Extruding, and Alloying
          • 6 Digit Code(s) NAICS 331491: Nonferrous Metal (except Copper and Aluminum) Rolling, Drawing, and Extruding
          • 6 Digit Code(s) NAICS 331492: Secondary Smelting, Refining, and Alloying of Nonferrous Metal (except Copper and Aluminum)
      • Industry Group 3315: Foundries
        • Industry 33151: Ferrous Metal Foundries
          • 6 Digit Code(s) NAICS 331511: Iron Foundries
          • 6 Digit Code(s) NAICS 331512: Steel Investment Foundries
          • 6 Digit Code(s) NAICS 331513: Steel Foundries (except Investment)
        • Industry 33152: Nonferrous Metal Foundries
          • 6 Digit Code(s) NAICS 331523: Nonferrous Metal Die-Casting Foundries
          • 6 Digit Code(s) NAICS 331524: Aluminum Foundries (except Die-Casting)
          • 6 Digit Code(s) NAICS 331529: Other Nonferrous Metal Foundries (except Die-Casting)

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NAICS 3 Digit Subsector Code 331