Company lists · Data refreshed September 2026

Top 25 Electrical insulation manufacturers based in the United States

Name: Electrical insulation manufacturers based in the United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 16, 2026 195 companies tracked

RevenueBase identified 195 electrical insulation manufacturers headquartered in the United States as of September 2026 and tracks 4,343 professional contacts across them, including 1,604 with verified work emails. Houston is the largest hub.

This list covers electrical insulation manufacturers headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 16, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 16, 2026 86% judged on-target in blind review

195Companies

4,343Contacts tracked

1,604Verified emails

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The 25 largest electrical insulation manufacturers based in the United States

Ranked by team size

Top 25 of 195 electrical insulation manufacturers based in the United States, ranked by team size, largest first. Data refreshed Sep 16, 2026. RevenueBase Smart Search rates how each company's information relates to electrical insulation manufacturers: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	SPI	Partial evidence	Charlotte, NC, United StatesHQ checked Sep 16, 2026	1,001-5,000	571 contacts →
	Partial evidence “SPI is a global leader in the Distribution and Specialty Fabrication of insulation products for Thermal, Acoustic, Fire Protection and Refractory applications.” Source: RevenueBase Database · checked Sep 16, 2026
2	The Okonite Company	Partial evidence	Ramsey, NJ, United StatesHQ checked Sep 16, 2026	1,001-5,000	477 contacts →
	Partial evidence “The Okonite Company was founded in 1878 making it one of the original insulators of electrical wire and cable in the United States.” Source: RevenueBase Database · checked Sep 16, 2026
3	Unifrax	Indirect evidence	Tonawanda, NY, United StatesHQ checked Sep 16, 2026	1,001-5,000	398 contacts →
	Indirect evidence “At Unifrax, we provide innovative solutions to our customers' application problems across several different industries.” Source: RevenueBase Database · checked Sep 16, 2026
4	NUTEC	Strong evidence	Huntersville, NC, United StatesHQ checked Sep 16, 2026	201-500	208 contacts →
	Strong evidence “NUTEC is a leading manufacturer of superior quality, high-temperature insulation and fire protection products.” Source: RevenueBase Database · checked Sep 16, 2026
5	Johns Manville Industrial Insulation	Strong evidence	Denver, CO, United StatesHQ checked Sep 16, 2026	201-500	141 contacts →
	Strong evidence “JM is the leading manufacturer of thermal insulation solutions for high and low-temperature industrial applications.” Source: RevenueBase Database · checked Sep 16, 2026
6	K-Flex USA	Partial evidence	Youngsville, NC, United StatesHQ checked Sep 16, 2026	201-500	133 contacts →
	Partial evidence “K-FLEX USA is the North American division of the IK Insulation Group, an innovative leader in flexible elastomeric foam insulation with 12 production facilities worldwide and a…” Source: RevenueBase Database · checked Sep 16, 2026
7	Enduro Composites	Partial evidence	Houston, TX, United StatesHQ checked Sep 16, 2026	51-200	105 contacts →
	Partial evidence “Enduro Composites is a vertically integrated manufacturer of FRP composites.” Source: RevenueBase Database · checked Sep 16, 2026
8	Mastermold, LLC	Partial evidence	Johnson Creek, WI, United StatesHQ checked Sep 16, 2026	51-200	93 contacts →
	Partial evidence “MasterMold, LLC is a multi-site, Wisconsin based manufacturer.” Source: RevenueBase Database · checked Sep 16, 2026
9	Epsilyte	Partial evidence	The Woodlands, TX, United StatesHQ checked Sep 16, 2026	201-500	87 contacts →
	Partial evidence “Epsilyte is one of North America’s leading producers of advanced insulative materials.” Source: RevenueBase Database · checked Sep 16, 2026
10	Plastics Engineering Company Plenco	Indirect evidence	Sheboygan, WI, United StatesHQ checked Sep 16, 2026	201-500	85 contacts →
	Indirect evidence “PLENCO is a materials company advancing the systems that power industry.” Source: RevenueBase Database · checked Sep 16, 2026
11	Jushi USA	Indirect evidence	Irwindale, CA, United StatesHQ checked Sep 16, 2026	5,001-10,000	84 contacts →
	Indirect evidence “Jushi Group, headquartered in the Tongxiang Economic Development Zone, Zhejiang, China, is one of the world’s largest producers of fiberglass reinforcements.” Source: RevenueBase Database · checked Sep 16, 2026
12	The Bayou Companies	Partial evidence	New Iberia, LA, United StatesHQ checked Sep 16, 2026	501-1,000	71 contacts →
	Partial evidence “Founded in 1942, Bayou is widely recognized as a market leader in onshore pipe coatings and offshore coatings and insulation, including highly-specialized insulation for the oil &…” Source: RevenueBase Database · checked Sep 16, 2026
13	Davlyn Group	Partial evidence	Spring City, PA, United StatesHQ checked Sep 16, 2026	201-500	69 contacts →
	Partial evidence “Davlyn Group is a leading U.S-based manufacturer of technical textiles and composites for the industrial, commercial, and residential markets.” Source: RevenueBase Database · checked Sep 16, 2026
14	Norplex-Micarta	Indirect evidence	Postville, IA, United StatesHQ checked Sep 16, 2026	51-200	63 contacts →
	Indirect evidence “Life Critical.” Source: RevenueBase Database · checked Sep 16, 2026
15	The Nelson Companies	Indirect evidence	Lake Zurich, IL, United StatesHQ checked Sep 16, 2026	51-200	53 contacts →
	Indirect evidence “Founded in 1958, The Nelson Companies is a family of independently operated specialty contracting businesses serving commercial, industrial, healthcare, education, manufacturing…” Source: RevenueBase Database · checked Sep 16, 2026
16	Haysite Reinforced Plastics LTD	Indirect evidence	Erie, PA, United StatesHQ checked Sep 16, 2026	51-200	51 contacts →
	Indirect evidence “Haysite Reinforced Plastics, located in Erie, PA, is among the worldwide leaders in the formulation and processing of thermoset composite materials.” Source: RevenueBase Database · checked Sep 16, 2026
17	Pacor INC	Partial evidence	Bordentown, NJ, United StatesHQ checked Sep 16, 2026	51-200	45 contacts →
	Partial evidence “With fabricating facilities in New Jersey, North Carolina and Georgia, Pacor custom fabricates and distributes fiberglass, aerogel, ceramic and foam industrial insulation products…” Source: RevenueBase Database · checked Sep 16, 2026
18	OLD Dominion Insulation	Partial evidence	Midlothian, VA, United StatesHQ checked Sep 16, 2026	501-1,000	41 contacts →
	Partial evidence “ODI is the premier insulation contractor in the commercial and industrial marketplace, specializing in mechanical insulation, low temperature refrigeration work, installation of…” Source: RevenueBase Database · checked Sep 16, 2026
19	Janco Engineered Products LLC	Partial evidence	Mishawaka, IN, United StatesHQ checked Sep 16, 2026	51-200	41 contacts →
	Partial evidence “Janco Engineered Products manufactures a wide range of advanced composites.” Source: RevenueBase Database · checked Sep 16, 2026
20	Insul-Therm International INC	Indirect evidence	Commerce, CA, United StatesHQ checked Sep 16, 2026	51-200	39 contacts →
	Indirect evidence “Insul-Therm Intl.” Source: RevenueBase Database · checked Sep 16, 2026
21	Shannon Global Energy Solutions	Strong evidence	North Tonawanda, NY, United StatesHQ checked Sep 16, 2026	51-200	36 contacts →
	Strong evidence “Manufacturer's of INSULTECH Thermal Acoustic Blanket Insulation systems.” Source: RevenueBase Database · checked Sep 16, 2026
22	TSG Resolute	Strong evidence	Americus, GA, United StatesHQ checked Sep 16, 2026	201-500	36 contacts →
	Strong evidence “TSG Resolute is the leading provider to the major OEM marketplaces for a wide range of products that includes gaskets, thermal insulation, acoustical insulation, electrical…” Source: RevenueBase Database · checked Sep 16, 2026
23	General Coatings Manufacturing Corp	Indirect evidence	Fresno, CA, United StatesHQ checked Sep 16, 2026	51-200	33 contacts →
	Indirect evidence “Over the past 25 years General Coatings Manufacturing Corp.” Source: RevenueBase Database · checked Sep 16, 2026
24	Neoinsulation	Partial evidence	Oklahoma City, OK, United StatesHQ checked Sep 16, 2026	51-200	33 contacts →
	Partial evidence “NeoInsulation: Engineering superior insulation solutions with innovative applications for today's energy infrastructure.” Source: RevenueBase Database · checked Sep 16, 2026
25	Gerome Technologies	Indirect evidence	Menands, NY, United StatesHQ checked Sep 16, 2026	51-200	33 contacts →
	Indirect evidence “Gerome Technologies Inc.” Source: RevenueBase Database · checked Sep 16, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: electrical insulation manufacturers. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names electrical insulation manufacturers.
Partial evidence: Its own public description names part of electrical insulation manufacturers, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name electrical insulation manufacturers. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 195 electrical insulation manufacturers based in the United States

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Electrical insulation manufacturers based in the United States at a glance

As of Sep 16, 2026

36.9%Verified-email coverage

22.3Average contacts per company

11-50Median size (employees)

4.6%Largest-city concentration · Houston

Sep 16, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

10001+

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 195 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among electrical insulation manufacturers, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in the United States whose own description of what they do matches “electrical insulation manufacturers”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search: RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names electrical insulation manufacturers), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude: Companies whose own description does not clearly place them among electrical insulation manufacturers, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 1,604 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 16, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names electrical insulation manufacturers, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many electrical insulation manufacturers are there based in the United States?

RevenueBase identified 195 electrical insulation manufacturers headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

SPI, headquartered in Charlotte, tops this list with the largest team on record.

Which city has the most electrical insulation manufacturers?

Houston leads with 9 headquartered companies, followed by Charlotte (3) and Miami (3).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,604 verified decision-maker contacts tracked across these 195 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 16, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.