Stef Wertheimer: The Galilee Industrialist Who Sold Iscar to Warren Buffett

The Builders  |  Olam.business

Published Jun 27, 2026.

Stef Wertheimer (born July 16, 1926, Kippenheim, Germany) is the founder of Iscar, the Tefen-based metal-cutting tools company that Berkshire Hathaway acquired in two stages — 80% in 2006 for $4 billion and the remaining 20% in 2013 for ~$2.05 billion — making Warren Buffett's first non-US acquisition and one of the largest Israeli industrial exits in history. He is also the architect of the Tefen industrial-park model that reshaped the Galilee economy, a former member of the Knesset, and an Israel Prize laureate.

Iscar produced the headline number. Tefen is the structural achievement. Both stories run in parallel, and you cannot understand Wertheimer without holding both.

Wertheimer arrived in Mandatory Palestine in 1937 as an eleven-year-old refugee from Nazi Germany. His Jewish family fled Kippenheim in Baden-Württemberg before the war made escape impossible. He served as an aircraft mechanic in the Royal Air Force during World War II, then in the nascent Israel Air Force during the 1948 war. He founded Iscar in 1952 in a small workshop in Nahariya, capitalized with personal savings, manufacturing metal-cutting tools — drills, milling cutters, lathe inserts — for the small Israeli industrial market.

Snapshot

Born	July 16, 1926, Kippenheim, Baden-Württemberg, Germany
Arrived in Palestine	1937, age 11 (refugee from Nazi Germany)
Founded Iscar	1952, Nahariya, Israel
First Berkshire transaction	2006 — Berkshire Hathaway acquired 80% of Iscar for $4 billion
Second Berkshire transaction	2013 — Berkshire acquired the remaining 20% for ~$2.05 billion
Tefen Industrial Park	Founded 1982, the prototype Galilee industrial cluster — the model later replicated across the Israeli periphery
Knesset service	1977–1981, on the Democratic Movement for Change list
Israel Prize	1991, for outstanding contribution to Israeli society and the economy
Family	Son Eitan Wertheimer chaired Iscar through both Berkshire transactions; grandson Ari Wertheimer is active in the group

The Business Story

Iscar's early years were small-workshop scale. By the 1960s the company had moved into precision-machined inserts, the highest-margin segment of the metal-cutting tools industry, where the unit economics depended on metallurgy, tolerances, and engineering refinement rather than raw labor cost. Wertheimer reinvested earnings into research and into recruiting metallurgists. The company gradually displaced larger European and American competitors on technical performance.

By the 1980s, Iscar had become a globally significant manufacturer of tungsten-carbide cutting tools. By the 2000s, it was one of the world's three or four largest, alongside Sweden's Sandvik, Germany's Kennametal-Widia, and Japan's Mitsubishi Materials. The company manufactures in Israel, Germany, India, China, South Korea, and other markets, selling primarily into automotive, aerospace, and general-engineering customers.

In May 2006, Warren Buffett announced that Berkshire Hathaway would acquire 80 percent of the holding company that controlled Iscar — IMC International Metalworking Companies — for $4 billion. The transaction was Berkshire's first acquisition of a non-US company. Buffett's letter to shareholders that year described Iscar in terms reserved for the businesses Berkshire most admires. Wertheimer family interests retained the remaining 20 percent.

In May 2013, Berkshire announced it would acquire the remaining 20 percent for $2.05 billion, valuing the company at approximately $10 billion in aggregate over the seven-year period. The 2013 transaction completed the sale and made Iscar a wholly owned Berkshire subsidiary. Iscar has operated under continuous Berkshire ownership since.

Why Wertheimer Matters in Israel

Three structural reasons.

First — Iscar is the canonical Israeli industrial exit. Most large Israeli exits before 2006 were in software, semiconductors, pharmaceuticals, or telecommunications. Iscar was a heavy-industrial manufacturer with metallurgy as its core technology and the Galilee as its operating geography. Buffett's $4 billion bet on Iscar validated Israeli industrial precision-engineering on a global stage and demonstrated that the country's industrial base could produce assets at multinational scale.

Second — Tefen is one of the most consequential pieces of Israeli industrial policy executed by a private actor. Wertheimer founded the Tefen Industrial Park in 1982 in the Western Galilee — a planned industrial cluster combining manufacturing facilities, a museum, an art collection, restaurants, and educational institutions. The model integrated industrial development with cultural and educational infrastructure, deliberately designed to make the periphery economically viable. Tefen became the prototype for a generation of Israeli industrial parks across the Galilee, the Negev, and the periphery. The Tefen model has shaped Israeli regional economic policy in ways that conventional industrial-zone planning had failed to achieve.

Third — the civic record. Wertheimer served in the Knesset from 1977 to 1981 on the Democratic Movement for Change list. He was awarded the Israel Prize in 1991 for outstanding contribution to Israeli society and the economy. He has been a consistent public advocate for Israeli-Arab industrial cooperation, regional economic integration, and against the political-religious polarization of the Israeli right and left.

What Iscar Does Today

Iscar is the anchor brand of IMC International Metalworking Companies, the wholly Berkshire-owned holding company. The group manufactures and sells precision metal-cutting tools — milling cutters, drilling tools, turning inserts, threading tools — into automotive, aerospace, energy, and general-engineering customers globally. The group operates manufacturing facilities in Israel, Germany, India, China, South Korea, and other jurisdictions.

The Israeli headquarters and original manufacturing facilities remain in the Tefen Industrial Park in the Western Galilee. The group is one of the largest single industrial employers in the Israeli periphery.

Wertheimer's Key Holdings and Legacy

• Iscar / IMC International Metalworking Companies — founder; sold in full to Berkshire Hathaway across two transactions (2006, 2013) for aggregate value of approximately $6 billion in cash to the family
• Tefen Industrial Park — founder; the prototype Galilee industrial cluster
• The Open Museum at Tefen — institutional museum integrated into the industrial park, housing modern Israeli art and historical exhibits
• Civic record — Knesset 1977–1981; Israel Prize 1991; public advocate for regional industrial integration
• Family continuity — son Eitan Wertheimer chaired Iscar through both Berkshire transactions; grandson Ari Wertheimer is active in the group; the broader Wertheimer family remains based primarily in Israel

Wertheimer's Legacy and Influence

Wertheimer is the canonical Israeli industrialist of the post-1948 generation. He built one of the world's largest precision-engineering companies in the periphery of a country with no comparative advantage in heavy industry, sold it to Warren Buffett at a price that validated the Israeli industrial base on a global stage, and built around it an industrial-park model that became the template for Galilee economic development. He has spent his post-Iscar years deepening the civic record rather than diversifying into new businesses.

Among the Israeli builders of his generation, Wertheimer is unusual in two respects. First — the asset is real industry, not capital allocation or natural-resource extraction. Iscar manufactures physical tools that are sold into competitive global engineering markets. Second — the civic record is structural, not symbolic. Tefen and the Open Museum and the Western Galilee industrial cluster have continued to compound long after the Iscar sale.

Why Wertheimer Matters Now

In 2026, as Israeli industrial policy navigates the rebuilding of the periphery after October 7 — including the northern border communities under sustained rocket fire through 2024 and the slow economic reconstruction of Galilee infrastructure — Wertheimer's Tefen model has reasserted itself as the operating reference. Multiple new Galilee industrial-cluster initiatives are explicitly modeled on Tefen.

The Iscar story remains, in Israeli public memory, the proof that Israeli industrial precision-engineering can compete at multinational scale. The Buffett endorsement gave Israel the validation. The Tefen model gave the periphery the operating template.

Wertheimer is in his late nineties. The family remains active in Iscar and in Israeli industrial life. The institutions he built continue.

FAQ

Who is Stef Wertheimer?
Stef Wertheimer (born July 16, 1926, Kippenheim, Germany) is the Israeli industrialist who founded Iscar — the metal-cutting tools manufacturer that Berkshire Hathaway acquired in two stages (2006, 2013) for aggregate value of approximately $6 billion. He also founded the Tefen Industrial Park, the prototype Galilee industrial cluster. He served in the Knesset 1977–1981 and was awarded the Israel Prize in 1991.

When did Berkshire Hathaway acquire Iscar?
Berkshire Hathaway acquired 80 percent of the holding company that controlled Iscar (IMC International Metalworking Companies) in May 2006 for $4 billion — Berkshire's first non-US acquisition. In May 2013, Berkshire acquired the remaining 20 percent for $2.05 billion, completing the transaction and making Iscar a wholly owned Berkshire subsidiary.

What is Iscar?
Iscar is an Israeli precision metal-cutting tools manufacturer founded by Wertheimer in 1952 in Nahariya. The company manufactures milling cutters, drilling tools, turning inserts, and threading tools for automotive, aerospace, energy, and general-engineering customers globally. It is the anchor brand of IMC International Metalworking Companies, wholly owned by Berkshire Hathaway since 2013.

What is the Tefen Industrial Park?
The Tefen Industrial Park is a planned industrial cluster founded by Wertheimer in 1982 in the Western Galilee. It combines manufacturing facilities, a museum, an art collection, restaurants, and educational institutions. The Tefen model became the prototype for a generation of Israeli industrial parks across the Galilee, the Negev, and the periphery.

How did Stef Wertheimer come to Israel?
Wertheimer arrived in Mandatory Palestine in 1937 as an eleven-year-old refugee from Nazi Germany. His Jewish family fled Kippenheim, Baden-Württemberg, before the war made escape impossible. He served as an aircraft mechanic in the Royal Air Force during World War II and then in the nascent Israel Air Force during the 1948 war.

What is Wertheimer's relationship with Warren Buffett?
Warren Buffett identified Iscar as one of the businesses Berkshire Hathaway most admired and acquired 80 percent of it in 2006 for $4 billion — Berkshire's first non-US acquisition. Buffett completed the acquisition with a second tranche in 2013 for $2.05 billion. The Wertheimer family and Buffett have maintained a close relationship before, during, and after the transactions.

Is Stef Wertheimer still alive?
Stef Wertheimer is in his late nineties. The Wertheimer family remains active in Iscar and in Israeli industrial and civic life, with son Eitan Wertheimer having chaired Iscar through both Berkshire transactions and grandson Ari Wertheimer active in the group.

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The Olam Editorial Team | The Builders / הבונים