Company lists · Data refreshed September 2026

Top 25 Oil filled transformer manufacturers worldwide

Name: Oil filled transformer manufacturers worldwide
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 30, 2026 3,337 companies tracked

RevenueBase identified 3,337 oil filled transformer manufacturers worldwide as of September 2026 and tracks 93,472 professional contacts across them, including 20,635 with verified work emails. India is the largest market and Bangalore the largest hub.

This list covers oil filled transformer manufacturers worldwide, 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 30, 2026. Country and city lists for oil filled transformer manufacturers follow the table.

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 30, 2026 86% judged on-target in blind review

3,337Companies

93,472Contacts tracked

20,635Verified emails

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The 25 largest oil filled transformer manufacturers worldwide

Ranked by team size

Top 25 of 3,337 oil filled transformer manufacturers worldwide, ranked by team size, largest first. Data refreshed Sep 30, 2026. RevenueBase Smart Search rates how each company's information relates to oil filled transformer 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	Littelfuse	Indirect evidence	Rosemont, IL, United StatesHQ checked Sep 30, 2026	10001+	4,259 contacts →
	Indirect evidence “Littelfuse, Inc.(NASDAQ: LFUS) is a diversified, industrial technology manufacturing company shaping solutions for the safe and efficient transfer of electrical energy.” Source: RevenueBase Database · checked Sep 30, 2026
2	C&s Electric LTD	Indirect evidence	New Delhi, IndiaHQ checked Sep 30, 2026	5,001-10,000	2,773 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 30, 2026
3	Powell	Indirect evidence	Houston, TX, United StatesHQ checked Sep 30, 2026	1,001-5,000	2,561 contacts →
	Indirect evidence “Powell is hiring- Powell is dedicated to improving people’s lives by providing reliable power distribution systems in every market we serve.” Source: RevenueBase Database · checked Sep 30, 2026
4	Prolec Energy	Indirect evidence	Apodaca, MexicoHQ checked Sep 30, 2026	5,001-10,000	2,322 contacts →
	Indirect evidence “Prolec has more than fifty years of experience in the creation of comprehensive solutions to meet the needs of power generation, transmission, and distribution.” Source: RevenueBase Database · checked Sep 30, 2026
5	Raychem RPG P LTD	Indirect evidence	Thane, IndiaHQ checked Sep 30, 2026	501-1,000	1,386 contacts →
	Indirect evidence “Raychem RPG is a joint venture between TE Connectivity, U.S.A.” Source: RevenueBase Database · checked Sep 30, 2026
6	Bharat Bijlee LTD	Indirect evidence	Mumbai, IndiaHQ checked Sep 30, 2026	1,001-5,000	1,144 contacts →
	Indirect evidence “Bharat Bijlee is a public-listed electrical engineering company headquartered in Mumbai, India.” Source: RevenueBase Database · checked Sep 30, 2026
7	Hubbell Power Systems	Partial evidence	Columbia, SC, United StatesHQ checked Sep 30, 2026	1,001-5,000	1,079 contacts →
	Partial evidence “Hubbell Power Systems (HPS) designs and manufactures a wide variety of electric power transmission, distribution, substation, underground, OEM, and communications products used by…” Source: RevenueBase Database · checked Sep 30, 2026
8	Maschinenfabrik Reinhausen	Indirect evidence	Regensburg, GermanyHQ checked Sep 30, 2026	1,001-5,000	1,052 contacts →
	Indirect evidence “MR: THE POWER BEHIND POWER We at MR have been writing our success story in the world of energy technology for more than 150 years.” Source: RevenueBase Database · checked Sep 30, 2026
9	Industrial Electric Mfg. IEM	Partial evidence	Fremont, CA, United StatesHQ checked Sep 30, 2026	1,001-5,000	969 contacts →
	Partial evidence “Industrial Electric Mfg.(IEM) is the largest independent full-line manufacturer of electrical distribution equipment and integrated power systems in the U.S.” Source: RevenueBase Database · checked Sep 30, 2026
10	Mitsubishi Electric Power Products, INC	Indirect evidence	Warrendale, PA, United StatesHQ checked Sep 30, 2026	1,001-5,000	967 contacts →
	Indirect evidence “Mitsubishi Electric Power Products, Inc.(MEPPI) is a leading U.S.” Source: RevenueBase Database · checked Sep 30, 2026
11	Howard Industries	Strong evidence	Ellisville, MS, United StatesHQ checked Sep 30, 2026	1,001-5,000	941 contacts →
	Strong evidence “Howard Industries is the leading manufacturer of liquid-filled distribution transformers for the utility and commercial/industrial markets.” Source: RevenueBase Database · checked Sep 30, 2026
12	SAE Towers	Indirect evidence	Houston, TX, United StatesHQ checked Sep 30, 2026	1,001-5,000	928 contacts →
	Indirect evidence “SAE Towers is one of the world’s largest producers of steel lattice towers for high-voltage power transmission.” Source: RevenueBase Database · checked Sep 30, 2026
13	Vijai Electricals Limited, Hyderabad	Indirect evidence	Hyderabad, IndiaHQ checked Sep 30, 2026	5,001-10,000	920 contacts →
	Indirect evidence “Vijai Electricals Ltd.” Source: RevenueBase Database · checked Sep 30, 2026
14	Astor A.Ş	Partial evidence	Ankara, TürkiyeHQ checked Sep 30, 2026	1,001-5,000	839 contacts →
	Partial evidence “Astor Enerji is an innovative company leading the electromechanical manufacturing industry sector by manufacturing and selling transformers with its knowledge of nearly 40 years…” Source: RevenueBase Database · checked Sep 30, 2026
15	Virginia Transformer Corp	Strong evidence	Roanoke, VA, United StatesHQ checked Sep 30, 2026	5,001-10,000	792 contacts →
	Strong evidence “Virginia Transformer is an engineering company that manufactures transformers.” Source: RevenueBase Database · checked Sep 30, 2026
16	AL Ahleia Switchgear Co. Kscc	Indirect evidence	Sabhan, KuwaitHQ checked Sep 30, 2026	1,001-5,000	708 contacts →
	Indirect evidence “Established in 1982 by Sayed Hamid Behbehani & Sons, Kuwait.* First Kuwaiti company to be awarded with ISO 9001 back in 1995 by DNV.* Company certified for ISO/TS 29001:2010…” Source: RevenueBase Database · checked Sep 30, 2026
17	Best Transformer	Strong evidence	Balıkesir, TürkiyeHQ checked Sep 30, 2026	1,001-5,000	696 contacts →
	Strong evidence “BEST Transformer, founded in 1966 in Balıkesir, produces oil-immersed distribution transformers, power transformers, cast resin dry-type transformers, reactors, and mechanical…” Source: RevenueBase Database · checked Sep 30, 2026
18	ALFEN	Partial evidence	Almere, NetherlandsHQ checked Sep 30, 2026	501-1,000	678 contacts →
	Partial evidence “With transformer substations, energy storage systems, charging stations for electric vehicles and a diverse portfolio of other products and services, Alfen has a central and…” Source: RevenueBase Database · checked Sep 30, 2026
19	Trench Group	Partial evidence	Berlin, GermanyHQ checked Sep 30, 2026	1,001-5,000	664 contacts →
	Partial evidence “As Trench Group, we are sage and VISIONARY INNOMAKERS leading the sustainable transformation of the electric power industry.” Source: RevenueBase Database · checked Sep 30, 2026
20	Hammond Power Solutions	Strong evidence	Guelph, ON, CanadaHQ checked Sep 30, 2026	1,001-5,000	636 contacts →
	Strong evidence “Hammond Power Solutions is a North American leader for the design and manufacture of dry-type standard and custom electrical engineered magnetics, liquid filled and cast resin…” Source: RevenueBase Database · checked Sep 30, 2026
21	Kirloskar Electric Co. LTD	Partial evidence	Bangalore, IndiaHQ checked Sep 30, 2026	1,001-5,000	621 contacts →
	Partial evidence “Kirloskar Electric Company Limited (KEC) is one of India 's leading manufacturers of electrical and power equipment.” Source: RevenueBase Database · checked Sep 30, 2026
22	Transformers & Rectifiers India LTD	Strong evidence	Ahmedabad, IndiaHQ checked Sep 30, 2026	1,001-5,000	580 contacts →
	Strong evidence “Transformer & Rectifier (India) Limited (TARIL) is one of India’s leading transformer manufacturers, with over four decades of engineering excellence and a strong global presence.” Source: RevenueBase Database · checked Sep 30, 2026
23	Wholesale Electric Supply Co. Of Houston, INC	Indirect evidence	Houston, TX, United StatesHQ checked Sep 30, 2026	501-1,000	544 contacts →
	Indirect evidence “Wholesale Electric Supply Company of Houston, Inc.” Source: RevenueBase Database · checked Sep 30, 2026
24	Pfisterer	Indirect evidence	Winterbach, FranceHQ checked Sep 30, 2026	1,001-5,000	541 contacts →
	Indirect evidence “PFISTERER is a globally leading and independent technology company with head offices in Winterbach near Stuttgart, Germany.” Source: RevenueBase Database · checked Sep 30, 2026
25	Ermco-Eci	Indirect evidence	Dyersburg, TN, United StatesHQ checked Sep 30, 2026	1,001-5,000	520 contacts →
	Indirect evidence “ERMCO (Electric Research and Manufacturing Cooperative, Inc.) is headquartered in Dyersburg, Tennessee.” Source: RevenueBase Database · checked Sep 30, 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: oil filled transformer 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 oil filled transformer manufacturers.
Partial evidence: Its own public description names part of oil filled transformer manufacturers, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name oil filled transformer 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 3,337 oil filled transformer manufacturers worldwide

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Oil filled transformer manufacturers worldwide at a glance

As of Sep 30, 2026

22.1%Verified-email coverage

28.0Average contacts per company

11-50Median size (employees)

1.5%Largest-city concentration · Bangalore

Sep 30, 2026Page data refreshed

Companies by employee count

1-10

769

11-50

1,078

51-200

820

201-500

366

501-1,000

139

1,001-5,000

125

5,001-10,000

10001+

Email recency is reported on each country list linked below.

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 oil filled transformer 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.
Coverage: Every country. Country and city lists for oil filled transformer manufacturers are linked below.
What qualifies: Companies worldwide whose own description of what they do matches “oil filled transformer 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 oil filled transformer 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 oil filled transformer manufacturers, and records with no verified work email.
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, 20,635 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 30, 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.

Oil filled transformer manufacturers by location

19 lists · largest first

Every Oil filled transformer manufacturers list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

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 oil filled transformer 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 oil filled transformer manufacturers are there worldwide?

RevenueBase identified 3,337 oil filled transformer manufacturers worldwide 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?

Littelfuse, headquartered in Rosemont, tops this list with the largest team on record.

Which country has the most oil filled transformer manufacturers?

India leads with 709 companies, followed by the United States (290) and Türkiye (172). Every oil filled transformer manufacturers list by country and city is linked on this page.

Which city has the most oil filled transformer manufacturers?

Bangalore leads with 51 headquartered companies, followed by Vadodara (39) and Pune (36).

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 20,635 verified decision-maker contacts tracked across these 3,337 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 30, 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.