SIC 3433 — Heating Equipment, Except Electric and Warm Air Furnaces
Official OSHA SIC Manual Definition
Establishments primarily engaged in manufacturing heating equipment, except electric and warm air furnaces, including gas, oil, and stoker coal fired equipment for the automatic utilization of gaseous, liquid, and solid fuels. Establishments primarily engaged in manufacturing warm air furnaces are classified in Industry 3585; cooking stoves and ranges are classified in Industry 3631; boiler shops primarily engaged in the production of industrial, power, and marine boilers are classified in Industry 3443; and those manufacturing industrial process furnaces and ovens are classified in Industry 3567.
Description & Classification
SIC code 3433 representing 'Heating Equipment, Except Electric and Warm Air Furnaces' is an industry category in the Standard Industrial Classification (SIC) system under U.S. OSHA and Federal procurement registers.
Modern NAICS Crosswalk
Trace the modern equivalent classifications in the 2022 North American Industry Classification System (NAICS) database:
- NAICS 333414 - Heating Equipment (except Warm Air Furnaces) Manufacturing (via SIC1987:3433→NAICS1997:333414→2002:333414→2007:333414→2012:333414→2017:333414→2022:333414)
Classification Details
| SIC Code | 3433 |
|---|---|
| Industry Title | Heating Equipment, Except Electric and Warm Air Furnaces |
| Division | Division D: Manufacturing |
| Major Group | Major Group 34: Fabricated Metal Products, Except Machinery and Transportation Equipment |
| JSON Endpoint | View as JSON · API → |
| Source / Verified | US Census 1987 SIC Concordance / 2026-08-08 |
SIC vs NAICS Compliance & Common Mismatches
Legacy SIC code 3433 classifies commercial operations based on primary end-product or service output under the 1987 federal framework. In contrast, modern 2022 NAICS codes group establishments based on production process inputs.
When submitting public disclosures to SEC EDGAR or determining OSHA workplace safety log recordkeeping exemptions (29 CFR Part 1904), rely strictly on the official OSHA 4-digit SIC classification rather than an automated commercial translation.
💡 Expert Guidance: SIC to NAICS Conversion
Common Compliance Mistake: Many contractors and B2B analysts confuse legacy 4-digit SIC codes like 3433 with modern 6-digit NAICS codes. Ensure that you use the correct active 2022 NAICS code (e.g. from the crosswalk below) when submitting representations on SAM.gov, as federal contracting officers only accept modern NAICS codes.
Related Pages & Tools
Further regulatory reference links for legacy SIC code 3433:
- SIC Codes Complete Compliance Guide — Detailed history and active legal applications of the SIC classification framework.
- Why Legacy SIC Codes Persist Guide — How credit systems and the SEC still rely on SIC metadata.
- SIC ↔ NAICS Crosswalk Tool — Trace industrial code conversions dynamically.
- SIC 3433 to NAICS Crosswalk — Bidirectional mapping to modern NAICS codes (Heating Equipment, Except Electric and Warm Air Furnaces).
- SIC Major Group 34 Hub — View other legacy industries in this business division.
Frequently Asked Questions (FAQ)
What industry sector is represented by legacy SIC code 3433? ▾
Legacy SIC code 3433 represents 'Heating Equipment, Except Electric and Warm Air Furnaces', categorized under Division Division D: Manufacturing and Major Group Major Group 34: Fabricated Metal Products, Except Machinery and Transportation Equipment. The Standard Industrial Classification (SIC) system was developed in the late 1930s.
What is the modern 2022 NAICS equivalent for legacy SIC 3433? ▾
Legacy SIC code 3433 maps to the modern 2022 NAICS industry classifications: NAICS 333414 (Heating Equipment (except Warm Air Furnaces) Manufacturing). Mappings are resolved transitively across successive updates to handle splits.
Why do credit agencies and banks still reference legacy SIC code 3433? ▾
Registries like Dun & Bradstreet, insurance underwriters, and private platforms retain SIC code 3433 because their historical financial risk data and scoring models are indexed using the legacy 4-digit SIC framework.
Does the SEC EDGAR system allow searching public filings by SIC 3433? ▾
Yes. The SEC Division of Corporation Finance assigns a primary 4-digit SIC code to public companies. You can search the EDGAR database using SIC code 3433 to group reporting peer firms.
How do OSHA safety recordkeeping rules apply to SIC code 3433? ▾
Under 29 CFR Part 1904 safety regulations, OSHA references legacy SIC codes including 3433 to determine if a physical establishment is required to maintain daily injury logs (Form 300) or is partially exempt.
What is the structural difference between SIC 3433 and NAICS codes? ▾
SIC code 3433 classifies establishments based on their final product output or market destination (what they sell), while modern NAICS codes classify them based on production processes and inputs (how they work).
What are the typical business activities classified under legacy SIC 3433? ▾
Typical business activities classified under legacy SIC 3433 are the operations associated with 'Heating Equipment, Except Electric and Warm Air Furnaces'. Mapped modern NAICS codes can be referenced for specific current examples.
Is legacy SIC code 3433 uniform across all 50 U.S. states? ▾
Yes, the Standard Industrial Classification (SIC) system, including code 3433, was published as a federal standard and remains uniform nationwide. It is still referenced by various state workers' compensation boards and departments of labor.
Sources & References
- U.S. Department of Labor (OSHA): OSHA Standard Industrial Classification (SIC) Manual — Code 3433
- U.S. Census Bureau: 1987 SIC to 2022 NAICS Concordance Tables
- Federal Reserve Board: Industrial Production & Capacity Utilization Classifications
- Internal Revenue Service (IRS): Schedule C Principal Business Activity (PBA) Industry Concordance
- Office of Management and Budget (OMB): Standard Industrial Classification Systems Governance