NAICS 335311 Quarterly Industry Report
Power, Distribution, and Specialty Transformer Manufacturing
Comprehensive industry research for valuation professionals, business owners, buyers, and lenders
NAICS Code: 335311Sector: 33Updated: Q1 2026
About This Report
This Fair Market Value industry report for NAICS 335311 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 power, distribution, and specialty transformer manufacturing. Reports are updated quarterly to reflect new Census releases and regulatory changes.
Industry Snapshot
Key metrics for the power, distribution, and specialty transformer manufacturing industry.
Industry Definition & Overview
Power, Distribution, and Specialty Transformer Manufacturing (NAICS 335311) encompasses establishments primarily engaged in manufacturing power, distribution, and specialty transformers (except electronic components). These transformers step up or step down voltage levels but do not convert between alternating and direct current. Products include liquid-filled power transformers for utility substations, dry-type distribution transformers for commercial buildings, pad-mounted transformers for underground distribution systems, and specialty transformers for industrial process control. The U.S. Census Bureau[5] classifies this industry under electrical equipment manufacturing.
Roughly 258 active businesses employ an estimated 18,600 workers in this industry. Production splits between large power transformers rated above 60 MVA that serve high-voltage transmission networks and smaller distribution transformers rated below 10 MVA that deliver electricity to end users. Large power transformer manufacturing requires specialized heavy fabrication capabilities including core stacking, coil winding, tank welding, and vacuum oil processing. Lead times for custom-engineered large power transformers can exceed 18 months due to design complexity and limited global production capacity.
Distribution transformer production operates at higher volumes with more standardized designs, though utilities still specify custom configurations for voltage ratings, tap changers, and mounting styles. Grain-oriented electrical steel represents the primary raw material, and global supply constraints for this specialty steel grade directly affect production costs and lead times. Federal and state mandates for transformer efficiency under Department of Energy standards require manufacturers to invest in amorphous metal core technology and premium-grade electrical steel to meet minimum performance requirements.
What's Included in This Industry
- Power transformer manufacturing for utility substations
- Distribution transformer production for electrical grids
- Specialty transformer manufacturing for industrial applications
- Pad-mounted transformer production for underground systems
- Dry-type transformer manufacturing for commercial buildings
- Instrument transformer and current transformer production
- Voltage regulator manufacturing for power distribution
- Step-up and step-down transformer production
- Liquid-filled transformer manufacturing and assembly
- Autotransformer and reactor coil production
NAICS Classification Hierarchy
| Level | Description | Code |
|---|---|---|
| Subsector | Electrical Equipment, Appliance, and Component Manufacturing | 335 |
| Industry Group | Electrical Equipment Manufacturing | 3353 |
| NAICS Industry | Electrical Equipment Manufacturing | 33531 |
| National Industry | Power, Distribution, and Specialty Transformer Manufacturing | 335311 |
Related NAICS Codes
| Code | Description | Relationship |
|---|---|---|
| 335312 | Motor and Generator Manufacturing | Manufactures motors and generators that convert electrical energy to mechanical energy or vice versa rather than the voltage-changing transformers produced in this classification |
| 335313 | Switchgear and Switchboard Apparatus Manufacturing | Produces switchgear and switchboard apparatus that control and protect electrical circuits rather than the transformers that change voltage levels in power distribution systems |
| 335314 | Relay and Industrial Control Manufacturing | Manufactures relays and industrial control equipment used alongside transformers in power systems but classified separately from transformer production itself |
| 334416 | Capacitor, Resistor, Coil, Transformer, and Other Inductor Manufacturing | Produces electronic transformers, inductors, and coils for circuit board applications rather than the power and distribution transformers serving electrical utility infrastructure |
| 335999 | All Other Miscellaneous Electrical Equipment and Component Manufacturing | Manufactures miscellaneous electrical equipment not classified elsewhere, distinguished from the specific transformer manufacturing activities covered by this dedicated industry code |
| 335921 | Fiber Optic Cable Manufacturing | Produces fiber optic cable used in power grid communication systems rather than the electromagnetic transformers that change voltage levels in electrical distribution networks |
Geographic Concentration
Top states by share of national establishments.
| # | State | % Est. | Total Est. |
|---|---|---|---|
| 1 | California | 9.3% | 21 |
| 2 | Texas | 7.5% | 17 |
| 3 | Pennsylvania | 7.0% | 16 |
| 4 | New York | 6.6% | 15 |
| 5 | Florida | 5.7% | 13 |
| 6 | Illinois | 5.7% | 13 |
| 7 | Missouri | 5.3% | 12 |
| 8 | New Jersey | 5.3% | 12 |
| 9 | Virginia | 4.0% | 9 |
| 10 | Georgia | 4.0% | 9 |
% Of Establishments
0%
9%
Source: County Business Patterns, U.S. Census Bureau[3]
SBA Lending Summary
32
Total SBA Loans
$5.3M
Total Loan Volume
$167K
Average Loan Size
9 yrs
Average Loan Term
10.81%
Average Interest Rate
40
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 335311 at 800 employees. Firms below this threshold qualify for small business set-aside contracts and SBA-backed lending programs. Federal procurement includes distribution transformers for military installations, pad-mounted units for VA medical centers, and specialty transformers for Department of Energy research facilities. The SBA's contracting programs[8] support manufacturers pursuing Defense Logistics Agency and Army Corps of Engineers transformer supply 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 | Northeast Bank | 8 | $2.7M | $333K |
| 2 | Regions Bank | 8 | $1.6M | $200K |
| 3 | Highmark FCU | 8 | $960K | $120K |
| 4 | Wells Fargo Bank National Association | 8 | $120K | $15K |
Frequently Asked Questions
Common questions about this industry.
What types of businesses are classified under NAICS 335311?
Manufacturers of power, distribution, and specialty transformers classify here. Products include utility-grade power transformers, distribution transformers for electrical grids, pad-mounted units, dry-type commercial transformers, instrument transformers, and voltage regulators per the Census Bureau[5] classification.
How is the transformer manufacturing industry structured?
Roughly 258 businesses employ an estimated 18,600 workers per Census data[11]. Production segments by transformer size: large power transformers above 60 MVA require custom engineering with lead times exceeding 18 months, while distribution transformers below 10 MVA use more standardized designs at higher production volumes.
What is the SBA size standard for NAICS 335311?
The SBA[7] sets the threshold at 800 employees. Businesses with fewer than 800 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 transformer manufacturing?
Related codes include 335312 (Motors and Generators), 335313 (Switchgear), 335314 (Relays and Industrial Controls), 334416 (Electronic Transformers), 335999 (Miscellaneous Electrical Equipment), and 335921 (Fiber Optic Cable). Each covers electrical equipment types that differ from the power and distribution transformers in this code.
What industries purchase power and distribution transformers?
Electric utilities, power line construction contractors, switchgear manufacturers, and steel producers interact most directly. Utilities purchase distribution transformers for service connections while power line contractors install units during grid construction and modernization projects across transmission and distribution networks.
What activities are included in NAICS 335311?
Activities include manufacturing liquid-filled power transformers for substations, producing dry-type distribution transformers for commercial buildings, fabricating pad-mounted transformers for underground systems, winding specialty instrument transformers and current transformers, assembling voltage regulators, and manufacturing autotransformers and reactor coils for power system applications.
Can transformer manufacturers qualify for SBA loans?
Yes, firms below 800 employees qualify for SBA lending programs[8] including 7(a) and 504 loans. Core stacking equipment, coil winding machines, vacuum oil processing systems, and tank fabrication tooling represent capital investments suited to SBA 504 equipment financing.
Where are transformer manufacturers concentrated?
Manufacturing concentrates in the Southeast and Midwest, with clusters in Virginia, Mississippi, Wisconsin, and Pennsylvania near major utility service territories and electrical steel suppliers. Proximity to rail terminals matters for shipping large power transformers that can weigh over 400,000 pounds. Several foreign-owned manufacturers operate U.S. plants to serve domestic utility customers and meet Buy America procurement requirements.
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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