SIC 3743 — Railroad Equipment
Official OSHA SIC Manual Definition
Establishments primarily engaged in building and rebuilding locomotives (including frames and parts, not elsewhere classified) of any type or gauge; and railroad, street, and rapid transit cars and car equipment for operation on rails for freight and passenger service. Establishments primarily engaged in manufacturing mining cars are classified in Industry 3532. Repair shops, owned and operated by railroads or local transit companies, repairing locomotives or cars for their oWn use are classified in Transportation, Major Groups 40 and 41. Establishments primarily engaged in repairing railroad cars on a contract or fee basis are classified in Transportation, Industry 4789; and those repairing locomotive engines on a contract or fee basis are classified in Services, Industry 7699.
Description & Classification
SIC code 3743 representing 'Railroad Equipment' 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 333914 - Measuring, Dispensing, and Other Pumping Equipment Manufacturing (via SIC1987:3743→NAICS1997:333911→2002:333911→2007:333911→2012:333911→2017:333914→2022:333914)
- NAICS 336510 - Railroad Rolling Stock Manufacturing (via SIC1987:3743→NAICS1997:33651→2002:336510→2007:336510→2012:336510→2017:336510→2022:336510)
Classification Details
| SIC Code | 3743 |
|---|---|
| Industry Title | Railroad Equipment |
| Division | Division D: Manufacturing |
| Major Group | Major Group 37: 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 3743 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 3743 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 3743:
- 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 3743 to NAICS Crosswalk — Bidirectional mapping to modern NAICS codes (Railroad Equipment).
- SIC Major Group 37 Hub — View other legacy industries in this business division.
Frequently Asked Questions (FAQ)
What industry sector is represented by legacy SIC code 3743? ▾
Legacy SIC code 3743 represents 'Railroad Equipment', categorized under Division Division D: Manufacturing and Major Group Major Group 37: Transportation Equipment. The Standard Industrial Classification (SIC) system was developed in the late 1930s.
What is the modern 2022 NAICS equivalent for legacy SIC 3743? ▾
Legacy SIC code 3743 maps to the modern 2022 NAICS industry classifications: NAICS 333914 (Measuring, Dispensing, and Other Pumping Equipment Manufacturing), NAICS 336510 (Railroad Rolling Stock Manufacturing). Mappings are resolved transitively across successive updates to handle splits.
Why do credit agencies and banks still reference legacy SIC code 3743? ▾
Registries like Dun & Bradstreet, insurance underwriters, and private platforms retain SIC code 3743 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 3743? ▾
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 3743 to group reporting peer firms.
How do OSHA safety recordkeeping rules apply to SIC code 3743? ▾
Under 29 CFR Part 1904 safety regulations, OSHA references legacy SIC codes including 3743 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 3743 and NAICS codes? ▾
SIC code 3743 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 3743? ▾
Typical business activities classified under legacy SIC 3743 are the operations associated with 'Railroad Equipment'. Mapped modern NAICS codes can be referenced for specific current examples.
Is legacy SIC code 3743 uniform across all 50 U.S. states? ▾
Yes, the Standard Industrial Classification (SIC) system, including code 3743, 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 3743
- 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