Ishikawa Gasket Co., Ltd.

Ishikawa Gasket Co., Ltd. is a Japanese manufacturer of gaskets and sealing components for internal combustion engines. Founded in May 1932 by Katsushiro Ishikawa, the company is headquartered in Toranomon, Minato-ku, Tokyo, and operates under the brand mark of the cherry blossom (sakura) seal. Its core business is the development and production of gaskets that seal the joints between dissimilar materials inside engines, preventing leakage of combustion gas, coolant and lubricating oil at microscopic levels. The company is best known for developing the steel laminated gasket in 1970, which it supplied to Isuzu Motors and which became the mainstream technology in gasket production worldwide. This innovation is registered as historical material of industrial technology at the National Science Museum of Japan (reference number 107310821007). Ishikawa Gasket's product range includes steel laminated head gaskets, steel best gaskets, manifold gaskets, overhaul gasket kits and heat insulators, developed under a "total sealing system" concept. Ishikawa Gasket serves automotive and industrial engine markets, with particular strength in medium- and large-sized diesel engines used in commercial vehicles, construction machinery and industrial equipment, as well as marine and agricultural engines. The company states that its gaskets are used and evaluated in approximately 60 countries. It operates sales offices in Tokyo, Nagoya and Osaka, a factory in Utsunomiya, and a branch in Turin, Italy. In recent years it has also begun developing and mass-producing secondary battery components for automotive use, diversifying beyond traditional engine sealing. The company remains privately held and family-influenced: founder Katsushiro Ishikawa was succeeded by his son Itsuo Ishikawa, and the current representative director and president is Shinichiro Ishikawa. In March 2025 Ishikawa Gasket became an official sponsor of the professional basketball team Utsunomiya Brex of the B.LEAGUE, reflecting its ties to the Utsunomiya region where its factory is located.

Ishikawa Gasket Co., Ltd. was founded in May 1932 by Katsushiro Ishikawa in Japan, at a time when the domestic market was dominated by American automobiles and repair parts were mostly imported. The founder's aim was to produce genuine gaskets made in Japan. The company adopted the cherry blossom (sakura) mark as its brand symbol, which became a mark of trust in the gasket industry. In the decades that followed, Ishikawa Gasket grew into a specialist in engine sealing. A major turning point came in 1970, when the company developed the world's first steel laminated gasket, replacing the soft materials traditionally used with stacked metal plates. This innovation was supplied to Isuzu Motors and is recognized as an epoch-making development in gasket technology; it is registered as historical material of industrial technology at the National Science Museum of Japan (reference number 107310821007, year of manufacture 1970, research agency: Japan Auto Parts Industries Association). Steel laminated gaskets subsequently became the mainstream technology in gasket production worldwide. The second generation of leadership, led by Itsuo Ishikawa, promoted direct sales to automobile manufacturers and the development of overseas markets, expanding the value and reach of the company's products. Under this strategy, the sakura-branded gaskets gained a reputation for reliability and came to be evaluated in approximately 60 countries. In the 2000s and 2010s, the global automotive industry began shifting toward electrification, with electric vehicles (EVs) and fuel cell vehicles (FCVs) promoted as part of decarbonization efforts. Ishikawa Gasket responded by focusing on medium- and large-sized diesel engine components for commercial vehicles, construction machinery and industrial equipment, where it expects diesel and natural gas engines to remain important for large vehicles. The company also began developing and mass-producing secondary battery components for automotive use, entering a new field beyond traditional engine sealing. In March 2025, Ishikawa Gasket became an official sponsor of the professional basketball team Utsunomiya Brex of the B.LEAGUE, citing shared values of regional revitalization and global challenge, and its connection to Utsunomiya where its factory is located. The company also launched a laser processing business page in the same month, indicating continued diversification of its manufacturing capabilities. As of the mid-2020s, Ishikawa Gasket remains a privately held company headquartered in Tokyo, with sales offices in Tokyo, Nagoya and Osaka, a factory in Utsunomiya, and a branch in Turin, Italy.

• 2025

  Became official sponsor of Utsunomiya Brex (B.LEAGUE) in March.

• 2025

  Launched laser processing business page in March.

• 1970

  Developed the world's first steel laminated gasket and supplied it to Isuzu Motors.

• 1970

  Steel laminated gasket registered as historical material of industrial technology at the National Science Museum (reference number 107310821007).

• 1932

  Founded in May by Katsushiro Ishikawa in Japan.

High-performance, high-reliability engine sealing specialist focused on medium- and large-sized diesel engines and total sealing systems.

• Steel laminated head gasket

  Flagship high-performance gasket for diesel, gasoline, small, large, passenger, commercial, industrial and construction machinery engines.

• Steel best gasket

  Combines thin steel plate and sheet, using graphite or beater sheet for high quality and reasonable cost.

• Manifold gasket

  For intake/exhaust manifolds, turbochargers, EGR and intake/exhaust fuel pipes.

• Overhaul gasket kit

  Kit of heat- and pressure-resistant sealing parts for cylinder head, exhaust manifold, intake manifold and exhaust pipe.

• Heat insulator

  Provides heat protection for engine parts with excellent heat shielding structure and precision press processing.

• Automotive secondary battery components

  Newly developed and mass-produced components for automotive secondary batteries.

1. 1石川ガスケット株式会社 公式サイトi-gas.co.jp
2. 2会社概要/About us | 石川ガスケット株式会社i-gas.co.jp
3. 3製品紹介/Products | 石川ガスケット株式会社i-gas.co.jp
4. 4About us | 石川ガスケット株式会社i-gas.co.jp
5. 5Ishikawa Gasket Co., Ltd. (Japan) - Wikidatawikidata.org