NAICS 331313

Overview

The North American Industry Classification System (NAICS) is the standard used by U.S. federal statistical programs to classify business establishments for collecting, analyzing, and publishing economic data. Developed under the Office of Management and Budget (OMB) and adopted in 1997, it was jointly designed with Statistics Canada and Mexico’s INEGI to enable cross-country comparability. ¹

NAICS 331313 — Alumina Refining and Primary Aluminum Production — is a NAICS 2022 national industry for establishments that refine alumina and produce primary aluminum from alumina. It distinguishes primary smelting and casting of aluminum from downstream rolling or fabricating sectors and supports consistent statistical reporting and procurement categorization. ²

See also on G2X:

• 331313
• 331314
• 331315

What this NAICS covers

• Refining alumina (aluminum oxide), generally from bauxite, as a primary activity. ³
• Making primary aluminum from alumina via electrolytic reduction. ³
• Casting primary aluminum forms (e.g., ingots, billets, slabs) as part of primary production. ³
• Producing aluminum-based primary metal from alumina (may include aluminum alloys produced during primary smelting). ³
• Integrated operations that make aluminum from alumina and roll/draw/extrude it into primary forms as part of the same establishment. ³
• Establishments classified in this industry are distinct from secondary smelters that recover aluminum from scrap. ³

Related NAICS and PSC codes

Scope boundaries and exclusions

• Recovering aluminum from scrap and/or alloying purchased aluminum is classified in 331314. ³
• Flat rolling or continuous casting of aluminum sheet/plate/foil from purchased aluminum is classified in 331315; extruding bar/pipe/tube from purchased aluminum is in 331316. ³
• Sorting or breaking up scrap metal without smelting/refining falls under wholesale trade; operating commingled recycling facilities without smelting/refining is in 562920. ³

Data vintage and comparability

NAICS 331313 is part of the NAICS 2022 revision. Census programs began publishing on the 2022 basis with the 2022 Economic Census First Look in 2024 and are phasing adoption across series through 2027, with bridge statistics to aid comparisons with 2017 NAICS. ⁵

Frequently asked questions

• What activities are included under NAICS 331313?

  • Alumina refining and the primary production of aluminum from alumina, including casting into primary forms such as ingots or billets when part of primary production. Operations that only recover aluminum from scrap are not included. ³

• What activities are excluded and classified elsewhere?

  • Secondary smelting/alloying from scrap is in 331314. Rolling/foil production from purchased aluminum is in 331315, and extrusions from purchased aluminum are in 331316. Scrap sorting without smelting/refining is outside this industry. ³

• Which PSC codes commonly align to materials in this industry’s supply chain?

  • Bauxite and other ores are coded under 9610; nonferrous primary forms like ingots and slabs under 9650. These PSCs capture raw and intermediate materials associated with primary aluminum production. ⁴

• When did NAICS 331313 take effect?

  • It is part of the NAICS 2022 vintage. Census began disseminating 2022-based statistics in 2024 releases and is phasing adoption across programs through 2027, with bridge tables to address code changes. ⁵

• Where can the official 2022 NAICS industry descriptions be found?

  • Census provides the 2022 NAICS descriptions file in its Industry Reference Files; it contains official titles and descriptions for 2022–2023 and supports consistent coding across data products. ⁶

Useful resources

• Census: Implementation of the 2022 NAICS (timeline, changes, bridge statistics). ⁵
• Census LEHD value labels (official code titles, includes 331313). ²
• Census Industry Reference Files — 2022 NAICS Descriptions (2022–2023). ⁶

References

1. U.S. Census Bureau — Classifying Businesses (history of NAICS adoption in 1997 and tri-national development). https://www.census.gov/about/history/historical-censuses-and-surveys/census-programs-surveys/economic/classifying-businesses.html
2. U.S. Census Bureau — LEHD Snapshot Documentation, Selected Codebook Value Labels (includes 331313 title). https://lehd.ces.census.gov/data/lehd-snapshot-doc/latest/appendices/value_labels.html
3. U.S. Census Bureau — NAICS Sector 31–33 archives (industry descriptions and cross-references for alumina refining and primary aluminum production). https://www.census.gov/naics/resources/archives/sect31-33.html
4. GSA Acquisition.gov — Product and Service Codes (PSC) Manual, April 2025 (definitions for 9610, 9650, etc.). https://www.acquisition.gov/psc-manual
5. U.S. Census Bureau — The Census Bureau’s Implementation of the 2022 NAICS (timeline and change overview). https://www.census.gov/library/reference/code-lists/naics/2022/implementation-timeline.html
6. U.S. Census Bureau — Industry Reference Files: 2022 NAICS Descriptions (2022–2023). https://www.census.gov/programs-surveys/nonemployer-statistics/technical-documentation/reference/naics-descriptions.html