333994 — Industrial Process Furnace and Oven Manufacturing
Description
This U.S. industry comprises establishments primarily engaged in manufacturing industrial process ovens, induction and dielectric heating equipment, and kilns (except cement, chemical, wood). Included in this industry are establishments manufacturing laboratory furnaces and ovens (as defined in the official U.S. Census Bureau 2022 NAICS Manual).
Exclusions & Cross-References
- Manufacturing bakery ovens--are classified in U.S. Industry 333241, Food Product Machinery
- Manufacturing;
- Manufacturing cement, wood, and chemical kilns--are classified in U.S. Industry 333248, All Other
- Industrial Machinery Manufacturing; and
- Manufacturing cremating ovens--are classified in U.S. Industry 333998, All Other Miscellaneous General
- Purpose Machinery Manufacturing.
Overview Facts
Legacy SIC Concordance
Trace the historical mapping chain from the 1987 Standard Industrial Classification (SIC) to the modern 2022 NAICS code format.
- SIC 2599 - Furniture and Fixtures, NEC (via SIC1987:2599→NAICS1997:339111→2002:339111→2007:333994→2012:333994→2017:333994→2022:333994)
- SIC 3567 - Industrial Process Furnaces and Ovens (via SIC1987:3567→NAICS1997:333994→2002:333994→2007:333994→2012:333994→2017:333994→2022:333994)
- SIC 3821 - Laboratory Apparatus and Furniture (via SIC1987:3821→NAICS1997:339111→2002:339111→2007:333994→2012:333994→2017:333994→2022:333994)
- SIC 3841 - Surgical and Medical Instruments and Apparatus (via SIC1987:3841→NAICS1997:339111→2002:339111→2007:333994→2012:333994→2017:333994→2022:333994)
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 3424 — Metal Heat Treating and Non-Thermal Treating Equipment
- PSC 4430 — Industrial Furnaces, Kilns, Lehrs, and Ovens
- PSC 4440 — Driers, Dehydrators, and Anhydrators
- PSC 6640 — Laboratory Equipment and Supplies
Source: DoD DPCAP PSC Selection Tool (Ingested: 2026-06-29)
Frequently Asked Questions (FAQ)
Is NAICS code 333994 valid in 2022? ▾
Yes, 333994 is a valid 6-digit 2022 NAICS national industry code representing 'Industrial Process Furnace and Oven Manufacturing' under Sector 31-33 in the official classification index.
What is the SBA size standard for NAICS code 333994? ▾
The Small Business Administration (SBA) has established a small business size standard of 500 employees for NAICS code 333994 (Industrial Process Furnace and Oven Manufacturing), calculated based on employees.
What is the legacy SIC equivalent for NAICS 333994? ▾
According to official Census Bureau concordance tables, NAICS code 333994 (Industrial Process Furnace and Oven Manufacturing) maps to legacy 1987 Standard Industrial Classification (SIC) codes: 2599 - Furniture and Fixtures, NEC, 3567 - Industrial Process Furnaces and Ovens, 3821 - Laboratory Apparatus and Furniture, 3841 - Surgical and Medical Instruments and Apparatus.
Related Pages & Tools
Further regulatory reference links for NAICS code 333994:
- 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.
- NAICS 333994 to SIC Crosswalk — Bidirectional mapping to legacy SIC codes (Industrial Process Furnace and Oven Manufacturing).
- 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.