NAICS 335931 Quarterly Industry Report
Current-Carrying Wiring Device Manufacturing
Comprehensive industry research for valuation professionals, business owners, buyers, and lenders
NAICS Code: 335931Sector: 33Updated: Q1 2026
About This Report
This Fair Market Value industry report for NAICS 335931 draws on verified data from the U.S. Census Bureau[5], Bureau of Labor Statistics[6], and the Small Business Administration[7]. Our research team compiles establishment counts, employment data, and SBA eligibility criteria specific to current-carrying wiring device manufacturing. Reports are updated quarterly to reflect new Census releases and regulatory changes.
Industry Snapshot
Key metrics for the current-carrying wiring device manufacturing industry.
Industry Definition & Overview
Current-Carrying Wiring Device Manufacturing (NAICS 335931) encompasses establishments primarily engaged in manufacturing current-carrying wiring devices that transmit electricity within buildings and equipment. Products include electrical receptacles and outlets, wall switches, lampholders, cord connectors, pin and sleeve industrial connectors, twist-lock devices, ground fault circuit interrupters (GFCIs), arc fault circuit interrupters (AFCIs), and USB-equipped outlet assemblies. The U.S. Census Bureau[5] classifies this industry under wiring device manufacturing within the electrical equipment sector.
Roughly 255 active businesses employ an estimated 15,800 workers in this industry. Production divides between high-volume commodity devices like duplex receptacles and toggle switches sold through electrical distribution, and specialty devices such as hospital-grade receptacles, explosion-proof connectors, and marine-rated plugs built to more stringent safety standards. A handful of large manufacturers dominate the residential and commercial wiring device market through brand recognition and established distributor relationships.
Manufacturing processes include injection molding of thermoplastic housings, stamping and forming of brass and copper contact components, automated assembly and riveting, and high-potential dielectric testing of finished units. UL listing and NEC compliance govern all products sold for permanent building wiring installation. Products must meet specific temperature ratings, amperage capacities, and environmental protection ratings depending on the intended application. Tamper-resistant receptacle designs became mandatory under NEC 2008 for dwelling unit installations, driving product redesign cycles across the residential product line. Weather-resistant and USB-integrated receptacles represent more recent product categories responding to code updates and consumer demand for built-in device charging capability.
What's Included in This Industry
- Electrical receptacle and outlet manufacturing
- Wall switch and dimmer production
- Lampholder and socket manufacturing
- Cord connector and attachment plug production
- GFCI and AFCI receptacle manufacturing
- Industrial pin and sleeve connector production
- Twist-lock device manufacturing
- USB-equipped outlet assembly
- Hospital-grade receptacle manufacturing
- Weather-resistant wiring device production
NAICS Classification Hierarchy
| Level | Description | Code |
|---|---|---|
| Subsector | Electrical Equipment, Appliance, and Component Manufacturing | 335 |
| Industry Group | Other Electrical Equipment and Component Manufacturing | 3359 |
| NAICS Industry | Wiring Device Manufacturing | 33593 |
| National Industry | Current-Carrying Wiring Device Manufacturing | 335931 |
Related NAICS Codes
| Code | Description | Relationship |
|---|---|---|
| 335932 | Noncurrent-Carrying Wiring Device Manufacturing | Manufactures noncurrent-carrying wiring devices such as conduit fittings and junction boxes rather than the current-carrying receptacles and switches produced here |
| 335313 | Switchgear and Switchboard Apparatus Manufacturing | Produces switchgear and switchboard apparatus for high-power distribution rather than the branch circuit wiring devices and connectors manufactured in this classification |
| 335929 | Other Communication and Energy Wire Manufacturing | Manufactures insulated wire and cable that connects to the wiring devices produced here but classifies under a separate wire and cable manufacturing code |
| 335131 | Residential Electric Lighting Fixture Manufacturing | Produces residential electric lighting fixtures that accept the lampholders manufactured here but classifies under lighting fixture manufacturing rather than wiring devices |
| 335314 | Relay and Industrial Control Manufacturing | Manufactures industrial relays and motor controls classified separately from the branch circuit switches, receptacles, and connectors produced in this wiring device industry |
| 335999 | All Other Miscellaneous Electrical Equipment and Component Manufacturing | Produces miscellaneous electrical equipment not classified elsewhere, distinguished from the specific current-carrying wiring devices covered by this dedicated industry code |
Geographic Concentration
Top states by share of national establishments.
| # | State | % Est. | Total Est. |
|---|---|---|---|
| 1 | California | 12.7% | 48 |
| 2 | Ohio | 7.1% | 27 |
| 3 | Texas | 6.9% | 26 |
| 4 | Illinois | 6.3% | 24 |
| 5 | Michigan | 6.1% | 23 |
| 6 | Pennsylvania | 4.8% | 18 |
| 7 | New York | 4.5% | 17 |
| 8 | North Carolina | 4.2% | 16 |
| 9 | Florida | 4.0% | 15 |
| 10 | Georgia | 3.7% | 14 |
% Of Establishments
0%
13%
Source: County Business Patterns, U.S. Census Bureau[3]
SBA Lending Summary
64
Total SBA Loans
$21.3M
Total Loan Volume
$333K
Average Loan Size
10 yrs
Average Loan Term
10.94%
Average Interest Rate
552
Jobs Supported
Source: SBA 7(a) Program Data, U.S. Small Business Administration — FY 2025[4]
Key Insight: The SBA[7] sets the size standard for NAICS 335931 at 1,000 employees. Firms below this threshold qualify for small business set-aside contracts and SBA-backed lending programs. Federal procurement includes hospital-grade receptacles for VA medical centers, GFCI devices for military housing upgrades, and explosion-proof connectors for Navy shipboard electrical systems. The SBA's contracting programs[8] support manufacturers pursuing General Services Administration and Defense Logistics Agency wiring device contracts. Eligible businesses can access SBA 7(a) loans[9] for working capital, equipment, and acquisition financing, while 504 loans[10] support major fixed-asset purchases including real estate and heavy machinery.
Top SBA Lenders
| # | Lender | Loans | Volume | Avg Loan |
|---|---|---|---|---|
| 1 | Newtek Bank, National Association | 48 | $20.0M | $417K |
| 2 | CDC Small Business Finance Corp. | 8 | $720K | $90K |
| 3 | Northeast Bank | 8 | $560K | $70K |
Frequently Asked Questions
Common questions about this industry.
What types of businesses are classified under NAICS 335931?
Manufacturers of current-carrying wiring devices classify here. Products include electrical receptacles, wall switches, lampholders, cord connectors, GFCIs, AFCIs, industrial pin and sleeve connectors, twist-lock devices, and USB-equipped outlets per the Census Bureau[5] classification.
How is the current-carrying wiring device industry structured?
Roughly 255 businesses employ an estimated 15,800 workers per Census data[11]. A few large manufacturers dominate residential and commercial commodity devices while smaller firms serve specialty segments including hospital-grade, explosion-proof, and marine-rated connector products.
What is the SBA size standard for NAICS 335931?
The SBA[7] sets the threshold at 1,000 employees. Businesses with fewer than 1,000 average employees qualify as small for federal contracting preferences and SBA-backed financing programs including 7(a) and 504 loans.
What NAICS codes are related to current-carrying wiring device manufacturing?
Related codes include 335932 (Noncurrent-Carrying Wiring Devices), 335313 (Switchgear), 335929 (Wire and Cable), 335131 (Residential Lighting), 335314 (Industrial Controls), and 335999 (Miscellaneous Electrical Equipment). Each covers electrical products that interface with but differ from the current-carrying wiring devices in this code.
What industries purchase current-carrying wiring devices?
Electrical contractors, electrical wholesalers, commercial builders, wire manufacturers, and plastics suppliers interact most directly. New residential and commercial construction drives the largest share of wiring device demand, with renovation and code-upgrade projects generating additional replacement volume through electrical distributor channels.
What activities are included in NAICS 335931?
Activities include manufacturing duplex and decorator receptacles, producing toggle and rocker wall switches, fabricating lampholders and sockets, assembling GFCI and AFCI protection devices, manufacturing industrial pin and sleeve connectors, producing twist-lock receptacles, and assembling USB-integrated outlet devices for residential and commercial building wiring installations.
Can wiring device manufacturers qualify for SBA loans?
Yes, firms below 1,000 employees qualify for SBA lending programs[8] including 7(a) and 504 loans. Injection molding presses, contact stamping dies, automated assembly lines, and UL-certified testing equipment represent capital investments suited to SBA 504 equipment financing.
Where are current-carrying wiring device manufacturers concentrated?
Manufacturing concentrates in the Northeast, Midwest, and Southeast near electrical distribution hubs and construction markets. Facilities in Connecticut, Wisconsin, Tennessee, and Mississippi serve national distribution networks. Several manufacturers operate both domestic assembly plants and overseas component sourcing operations to balance cost and lead time requirements for their product lines.
Sources & References
Government datasets and editorial sources used in this report.
- [1]U.S. Bureau of Labor Statistics, Quarterly Census of Employment and Wages bls.gov
- [2]U.S. Census Bureau, Economic Census census.gov
- [3]U.S. Census Bureau, County Business Patterns census.gov
- [4]U.S. Small Business Administration, SBA 7(a) Loan Program Data data.sba.gov
- [5]U.S. Census Bureau census.gov
- [6]Bureau of Labor Statistics bls.gov
- [7]Small Business Administration sba.gov
- [8]SBA's contracting programs sba.gov
- [9]SBA 7(a) loans sba.gov
- [10]504 loans sba.gov
- [11]Census data naicslist.com
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