NAICS 327993 Quarterly Industry Report
Mineral Wool Manufacturing
Comprehensive industry research for valuation professionals, business owners, buyers, and lenders
NAICS Code: 327993Sector: 32Updated: Q1 2026
About This Report
This Fair Market Value industry report for NAICS 327993 draws on data from the Bureau of Labor Statistics[7] employment surveys, Federal Reserve Economic Data[6] producer price indices, and SBA size standard publications[8]. Our research team tracks insulation production trends, energy code developments, and construction market drivers to provide valuation context for mineral wool manufacturing operations. Additional data is drawn from U.S. Census Bureau[9].. Updated quarterly, each statistic is sourced to its originating federal or institutional database.
Industry Snapshot
Key metrics for the mineral wool manufacturing industry.
Industry Definition & Overview
Mineral Wool Manufacturing (NAICS 327993) encompasses establishments primarily engaged in manufacturing mineral wool and mineral wool insulation products made from siliceous materials such as rock, slag, glass, or combinations thereof. Products include fiberglass batts and rolls, blown-in loose-fill insulation, rigid board insulation, pipe insulation, duct wrap, ceiling tiles, and acoustical panels.
Fiberglass insulation dominates this industry by production volume. Raw materials include silica sand, soda ash, limestone, and recycled glass cullet, which are melted in furnaces at temperatures exceeding 1,400 degrees Celsius and spun into fine fibers. Rock wool and slag wool products use basalt rock or blast furnace slag as feedstock. According to Statista[5], fiberglass and mineral wool manufacturing employed over 17,000 workers in the United States.
The industry is highly concentrated among a few large manufacturers that operate multiple plants with integrated glass melting and fiberizing lines. Building insulation for residential and commercial construction accounts for the largest end-use segment. Industrial insulation for pipe, equipment, and process applications represents a smaller but higher-margin segment. Energy code requirements from federal and state building standards drive minimum insulation R-values that support baseline demand. Producer price trends tracked by the Federal Reserve Bank of St. Louis[6] show insulation pricing has responded to both energy costs and construction activity levels.
What's Included in This Industry
- Fiberglass batt and roll insulation manufacturing
- Blown-in loose-fill fiberglass insulation production
- Rock wool and slag wool insulation manufacturing
- Rigid fiberglass board insulation production
- Fiberglass pipe insulation manufacturing
- Acoustical ceiling tile and panel production
- Fiberglass duct wrap and duct board manufacturing
- Mineral wool industrial insulation production
- Glass fiber mat manufacturing for roofing and flooring
- Mineral wool fire protection product manufacturing
NAICS Classification Hierarchy
| Level | Description | Code |
|---|---|---|
| Subsector | Nonmetallic Mineral Product Manufacturing | 327 |
| Industry Group | Other Nonmetallic Mineral Product Manufacturing | 3279 |
| NAICS Industry | All Other Nonmetallic Mineral Product Manufacturing | 32799 |
| National Industry | Mineral Wool Manufacturing | 327993 |
Related NAICS Codes
| Code | Description | Relationship |
|---|---|---|
| 327910 | Abrasive Product Manufacturing | Abrasive product manufacturing shares the same other nonmetallic mineral products industry group and processes mineral raw materials through high-temperature manufacturing |
| 327992 | Ground or Treated Mineral and Earth Manufacturing | Ground or treated mineral manufacturing processes nonmetallic minerals into industrial powders rather than fibrous insulation products made through glass melting |
| 327999 | All Other Miscellaneous Nonmetallic Mineral Product Manufacturing | Other miscellaneous nonmetallic mineral product manufacturing covers remaining products in the same industry group not classified under more specific codes |
| 327991 | Cut Stone and Stone Product Manufacturing | Cut stone manufacturing falls within the same industry group and processes nonmetallic minerals for construction, though end products serve different building functions |
| 423330 | Roofing, Siding, and Insulation Material Merchant Wholesalers | Roofing, siding, and insulation material merchant wholesalers distribute mineral wool insulation products to contractors and building material retailers |
Geographic Concentration
Top states by share of national establishments.
| # | State | % Est. | Total Est. |
|---|---|---|---|
| 1 | Texas | 14.3% | 32 |
| 2 | California | 9.4% | 21 |
| 3 | Ohio | 8.5% | 19 |
| 4 | Indiana | 6.7% | 15 |
| 5 | Pennsylvania | 5.8% | 13 |
| 6 | Florida | 5.8% | 13 |
| 7 | New York | 4.9% | 11 |
| 8 | Georgia | 4.5% | 10 |
| 9 | Tennessee | 4.0% | 9 |
| 10 | Wisconsin | 3.6% | 8 |
% Of Establishments
0%
14%
Source: County Business Patterns, U.S. Census Bureau[3]
SBA Lending Summary
16
Total SBA Loans
$2.6M
Total Loan Volume
$165K
Average Loan Size
10 yrs
Average Loan Term
12.38%
Average Interest Rate
224
Jobs Supported
Source: SBA 7(a) Program Data, U.S. Small Business Administration — FY 2025[4]
Key Insight: The SBA[8] classifies Mineral Wool Manufacturing under NAICS 327993 with a size standard of 1,500 employees. This high ceiling reflects the capital-intensive, large-furnace manufacturing operations typical of the insulation industry. The major producers exceed this threshold, but some regional manufacturers and specialty insulation producers qualify as small businesses. Eligible firms can access SBA lending programs[10] for furnace upgrades, production line expansions, and energy efficiency improvements. Eligible businesses can access SBA 7(a) loans[11] for working capital, equipment, and acquisition financing, while 504 loans[12] support major fixed-asset purchases including real estate and heavy machinery.
Top SBA Lenders
| # | Lender | Loans | Volume | Avg Loan |
|---|---|---|---|---|
| 1 | Newtek Bank, National Association | 8 | $2.4M | $300K |
| 2 | Manufacturers and Traders Trust Company | 8 | $240K | $30K |
Frequently Asked Questions
Common questions about this industry.
What types of businesses fall under NAICS 327993?
NAICS 327993 covers manufacturers of fiberglass insulation batts and rolls, blown-in loose-fill insulation, rock wool and slag wool products, rigid insulation boards, pipe insulation, acoustical ceiling tiles, and duct wrap. These range from large integrated manufacturers with glass melting furnaces and nationwide distribution to smaller specialty producers making industrial or acoustical products. Per the Federal Reserve[6], producer price indices track distinct product categories within mineral wool manufacturing.
How is NAICS 327993 organized within the classification system?
This code falls within Industry Group 3279 (Other Nonmetallic Mineral Product Manufacturing), Subsector 327 (Nonmetallic Mineral Product Manufacturing), and Sector 31-33 (Manufacturing). It shares Industry Group 3279 with codes for abrasive products (327910), cut stone (327991), ground minerals (327992), and miscellaneous nonmetallic products (327999).
What is the SBA size standard for NAICS 327993?
The SBA[8] sets the size standard at 1,500 employees for Mineral Wool Manufacturing. This is among the highest thresholds in the nonmetallic mineral product sector, reflecting the large scale and capital intensity of glass melting and fiberizing operations. Firms below this threshold qualify as small businesses.
Which NAICS codes are most closely related to 327993?
Within the same industry group, 327910 (abrasive products) and 327992 (ground minerals) share mineral processing characteristics. Drywall and insulation contractors (238310) are the primary customer segment. Per NAICS reference materials[13], the classification distinguishes mineral wool from other insulation types like foam plastic (326150) based on the mineral fiber raw material.
What industries have the strongest connections to mineral wool manufacturing?
Insulation contractors (238310) and commercial construction (236220) drive the largest demand volumes. Roofing and insulation wholesalers (423330) handle distribution. Chemical manufacturers (325199) supply binder resins. Silica sand mining (212319) provides glass-making raw materials. Masonry contractors (238140) install cavity wall and fire-stopping mineral wool products.
What specific activities are included in NAICS 327993?
Activities include melting glass or rock raw materials in furnaces, spinning molten material into mineral fibers, forming fiberglass batts, producing blown-in insulation, manufacturing rigid board insulation, making pipe and duct insulation wraps, producing acoustical ceiling tiles, and manufacturing fire protection mineral wool products. According to industry references, the defining characteristic is the mineral fiber base of all products.
Can mineral wool manufacturers access SBA loans?
Yes. Mineral wool manufacturers with fewer than 1,500 employees can access SBA loan programs[10] including 7(a) loans for working capital, 504 loans for furnace equipment and real estate, and export financing programs. These programs help smaller manufacturers invest in production capacity, energy efficiency upgrades, and environmental compliance systems.
Where is mineral wool manufacturing concentrated in the United States?
Production plants locate near silica sand deposits, transportation corridors, and major construction markets. Kansas, Ohio, Texas, and California support fiberglass insulation manufacturing. Rock wool plants operate near suitable basalt deposits or blast furnace slag sources in the industrial Midwest. Proximity to residential and commercial construction centers influences distribution and plant siting decisions for the building insulation segment.
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]Statista statista.com
- [6]Federal Reserve Bank of St. Louis fred.stlouisfed.org
- [7]Bureau of Labor Statistics bls.gov
- [8]SBA size standard publications sba.gov
- [9]U.S. Census Bureau census.gov
- [10]SBA lending programs sba.gov
- [11]SBA 7(a) loans sba.gov
- [12]504 loans sba.gov
- [13]NAICS reference materials naicslist.com
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