Uchiyama Manufacturing Corp.

Uchiyama Manufacturing Corp. (内山工業株式会社, Uchiyama Kogyo Kabushiki Kaisha) is a Japanese industrial manufacturer whose core technologies are sealing and insulation. Founded in 1898 in Hyogo Prefecture as a cork stopper maker under the name Uchiyama Koroppu Seizosho, the company grew into Japan's leading cork products manufacturer before shifting its main business toward rubber and resin gaskets and seals for automobiles and industrial machinery. Its product range today includes automotive gaskets, sealing materials, cork flooring, heat-insulating materials and cork stoppers, sold under the UMC brand and supplied to automotive and industrial customers in Japan and overseas. The company is headquartered in Okayama City, Okayama Prefecture, with its main office at 2-1-10 Kobashi-cho and its registered head office at 338 Enami, Naka-ku, Okayama. It operates domestic production plants in Okayama (Okayama Daiichi, Oku, Mitsu, Akasaka) and Chigasaki in Kanagawa Prefecture, supported by the UMC Akasaka Research Institute in Akaiwa, Okayama. Sales offices are located in Tokyo, Nagoya, Osaka and Hiroshima. The Uchiyama Group also includes domestic subsidiaries such as NE Seal Co., Ltd., Usan Precision Co., Ltd., Toyo Cork Co., Ltd., Usan Gasket Co., Ltd., Uchiyama Corporation and Yusan Co., Ltd., as well as overseas operations in the United States, Europe, Vietnam, South Korea and Portugal. Uchiyama Manufacturing was incorporated in 1956 as Uchiyama Cork Industry Co., Ltd. and changed its name to Uchiyama Kogyo Co., Ltd. in 1962. The company is privately held, with stated capital of 120 million yen. As of September 2025 it reported 1,006 employees and annual sales of 56.6 billion yen; the wider Uchiyama Group employed 7,114 people as of October 1, 2025. The current president is Kenzo Uchiyama. The company emphasizes material research, product development and integrated production engineering, and maintains a business continuity plan and crisis management framework centered on human life, corporate social responsibility and protection of the UMC brand.

Uchiyama Manufacturing Corp. traces its origins to 1898 (Meiji 31), when Uchiyama Koroppu Seizosho was established in Sayo District, Hyogo Prefecture, and began manufacturing cork stoppers. In 1930 the company succeeded in developing oil-resistant compressed cork, a first in Japan, and started producing cork discs and gaskets from compressed cork board. A carbonized cork board factory (now the Okayama Daiichi Plant) was built in Okayama Prefecture in 1933. By 1940 the company was authorized as a designated factory for the Ministry of Railways and the Army, Navy and Air Ordnance departments for its carbonized and compressed cork board production. In 1944 it took over the cork division of Toyo Kogyo (now Mazda) and established Toyo Cork Co., Ltd. In the postwar period Uchiyama continued to innovate: in 1950 it developed cork rubber for the first time in Japan; in 1951 it began manufacturing oil seals, industrial rubber products and cork rubber using synthetic rubber, and jointly developed synthetic rubber rollers for spinning. In 1953 it succeeded in producing expanded polystyrene and in the steam baking method for carbonized cork, both firsts in Japan. Uchiyama Kogyo Co., Ltd. (now Uchiyama Corporation) was established in 1955, and in 1956 the business was incorporated as Uchiyama Cork Industry Co., Ltd. In 1959 it developed a bearing seal with integrated metal core and synthetic rubber. In 1962 the company changed its name to Uchiyama Kogyo Co., Ltd. (Uchiyama Manufacturing Corp.). It began producing crown caps and flexible urethane foam at the Chigasaki Plant in 1966, and started exporting bearing seals overseas in 1969. The 1970s saw further diversification: the Tamiron sliding door was developed in 1972; the Polymode crown cap with polyethylene liner in 1973; Uchiyama America was established in New Jersey, USA, in 1975; synthetic rubber gasket production began in 1977; and NE Seal Co., Ltd. was established as a dedicated bearing seal factory in 1979. In 1981 Usan Gasket Co., Ltd. was founded as a dedicated hard gasket factory and production of Opack began; Usan Precision Co., Ltd. was established as a dedicated mold factory in 1982. The company developed compressed cork stoppers in 1984 and opened sales offices in Tokyo, Osaka, Toyama, Nagoya and Hiroshima in 1986. In 1988 it established Donga Giken Co., Ltd. (now Donga Uchiyama Co., Ltd.) in South Korea as a joint venture with Toa Kogyo Co., Ltd. In the 1990s Uchiyama expanded its research and international footprint: the UMC Akasaka Research Institute was completed in Okayama Prefecture in 1992; a European office was opened in Dusseldorf, Germany, in 1995; Uchiyama Portugal was established and began production in 1996; and Uchiyama America expanded in 1997. The company continues to operate as a privately held group with production and sales bases in Japan and overseas, and remains focused on sealing and insulation technologies for automotive and industrial applications.

• 1988

  Established Donga Giken Co., Ltd. (now Donga Uchiyama Co., Ltd.) in South Korea as a joint venture with Toa Kogyo Co., Ltd.

• 1986

  Opened sales offices in Tokyo, Osaka, Toyama, Nagoya and Hiroshima.

• 1984

  Developed and began producing compressed cork stoppers.

• 1982

  Established Usan Precision Co., Ltd. as a dedicated mold factory.

• 1981

  Established Usan Gasket Co., Ltd. as a dedicated hard gasket factory and began production of Opack.

• 1979

  Established NE Seal Co., Ltd. as a dedicated bearing seal factory.

• 1977

  Began production of synthetic rubber gaskets.

• 1975

  Established Uchiyama America in New Jersey, USA, and began sales.

• 1973

  Developed and began producing the Polymode crown cap with polyethylene liner.

• 1972

  Developed and began producing the Tamiron sliding door.

• 1969

  Began exporting bearing seals overseas.

• 1966

  Began manufacturing crown caps and flexible urethane foam at the Chigasaki Plant.

• 1962

  Changed company name to Uchiyama Kogyo Co., Ltd. (Uchiyama Manufacturing Corp.).

• 1959

  Developed a bearing seal with integrated metal core and synthetic rubber.

• 1956

  Incorporated as Uchiyama Cork Industry Co., Ltd.

• 1955

  Established Uchiyama Kogyo Co., Ltd. (now Uchiyama Corporation).

• 1953

  Succeeded in producing expanded polystyrene and in the steam baking method for carbonized cork, both firsts in Japan.

• 1951

  Began manufacturing oil seals, industrial rubber products and cork rubber using synthetic rubber; jointly developed synthetic rubber rollers for spinning.

• 1950

  Developed cork rubber for the first time in Japan.

• 1944

  Took over the cork division of Toyo Kogyo (now Mazda) and established Toyo Cork Co., Ltd.

• 1940

  Authorized as a designated factory for the Ministry of Railways and the Army, Navy and Air Ordnance departments for carbonized and compressed cork board production.

• 1933

  Built a carbonized cork board factory (now Okayama Daiichi Plant) in Okayama Prefecture and began production.

• 1930

  Succeeded in developing oil-resistant compressed cork for the first time in Japan; began manufacturing cork discs and gaskets from compressed cork board.

• 1898

  Established Uchiyama Koroppu Seizosho in Sayo District, Hyogo Prefecture, and began manufacturing cork stoppers.

A specialist manufacturer of sealing and insulation technologies, supplying automotive and industrial customers with gaskets, seals and cork-based products.

• Automotive gaskets

  Gaskets for automotive engines and industrial machinery.

• Sealing materials

  Oil seals, bearing seals and various sealing materials.

• Cork flooring

  Cork-based flooring products.

• Heat-insulating materials

  Insulation materials for housing and industrial use.

• Cork stoppers

  Cork stoppers, including compressed cork stoppers.

1. 1umc 内山工業株式会社umc-net.co.jp
2. 2会社概要｜umc 内山工業株式会社umc-net.co.jp
3. 3危機管理｜umc 内山工業株式会社umc-net.co.jp
4. 4国内拠点・海外拠点｜umc 内山工業株式会社umc-net.co.jp
5. 5Uchiyama Manufacturing Corp. (Japan) - Wikidatawikidata.org