Ihara Science Corporation

Ihara Science Corporation (イハラサイエンス株式会社) is a Japanese industrial manufacturer specialising in piping systems for fluids. Its origins date to April 1941, when Masaji Ihara founded the sole proprietorship Ihara Shokai in Shibahamamatsu-cho, Minato-ku, Tokyo, initially trading in electrical wire, conduit, iron pipe fittings and factory batteries. The business was incorporated as Ihara Sangyo Co., Ltd. in May 1947, and in 1952 it created the IS brand, marking its transition from trading house to manufacturer. In 1953 it began operating as a manufacturer of high-pressure fittings for piping, and in 1962 it was renamed Ihara High Pressure Fittings Industry Co., Ltd. (伊原高圧継手工業株式会社). The company listed its shares on the over-the-counter market (the predecessor of JASDAQ) in June 1963. The company's core product is the bite-type (flareless) fitting, which it named the "kuikomi tsugite" (くい込み継手) and commercialised after encountering the technology in a 1960 transaction with Mitsubishi Heavy Industries. The fitting was subsequently standardised as a Japanese Industrial Standard (JIS) and became an essential component of hydraulic piping. Over the decades Ihara Science expanded from hydraulic fittings into valves, hoses, pipes and complete piping systems, and today it organises its business into two divisions: the General Piping (GP) Division, serving general industrial piping for oil, air, water, steam, high-viscosity fluids and gas, and the Clean Piping (CP) Division, serving high-purity gas and liquid, pharmaceutical, food and pure-water applications, particularly in semiconductors, LCDs, energy, food and medical markets, and analytical and measuring instruments. The company positions itself around the concept of the "optimal piping system" (最適配管システム), offering design, machining, assembly and maintenance as a total package rather than individual components. Its IS mark is explained as standing for "Ai to Watashi to Science" (Love, Self and Science). Ihara Science operates sales offices in Tokyo (East Japan), Nagoya (Central Japan) and Osaka (West Japan), and manufacturing sites including the Izu-Nagaoka and Naka-Izu plants in Shizuoka, the Yamagata plant, and the Gifu plants (Tsukeji No. 1 and No. 2, and Ena-Kita). Group companies include Yamagata Ihara Co., Ltd. in Japan, Ihara Science USA Corporation with offices in California and Pennsylvania, Ihara Science Taiwan Co., Ltd. in Taichung, and Nantong Ihara Science Co., Ltd. in Jiangsu, China, which operates both GP and CP plants. The company states that it operates globally with bases in Japan and around the world. Recent corporate news includes a change of fiscal year-end and partial amendment of the articles of incorporation announced in December 2024, a capital reduction announced in April 2024, and notices in 2025 concerning a merger, changes to officers and changes to the corporate number and invoice number. The company also describes itself as supporting scholarship payments, research grants and forest conservation as a way of giving back to society and the community.

Ihara Science Corporation traces its history to April 1941, when Masaji Ihara, then 35 years old, founded the sole proprietorship Ihara Shokai at 3-2-2 Shibahamamatsu-cho, Minato-ku, Tokyo, with capital of 1,000 yen and four employees. The company handled products from Furukawa Electric, where the founder had previously worked, including electrical wire, conduit, iron pipe fittings and factory batteries. In May 1947 the business was incorporated as Ihara Sangyo Co., Ltd. with capital of 50,000 yen. In 1952 the company created the IS brand, marking its shift from trading house to manufacturer; products at the time included elbows, tees, valves, cocks and lubrication gauges. In 1953 it began operating as a manufacturer of high-pressure fittings for piping, investing heavily in forging dies when competitors hesitated, and expanding its customer base to include Toshiba Machine, Hitachi and Fuji Electric. In 1960 it acquired its own factory in Kumasaka, now part of Izu City, Shizuoka Prefecture. In 1958 it joined the Hydraulic Equipment Industry Association (now the Fluid Power Industry Association), and in 1959 Masaru Ihara, who would become the second president, joined the company; annual sales surpassed 100 million yen that year. The decisive product was the bite-type fitting, which Ihara encountered in 1960 through a transaction with Mitsubishi Heavy Industries. Recognising its potential as a hydraulic piping fitting that could connect high-pressure piping without welding or threading, the company developed and named it the "kuikomi tsugite" (bite-type fitting) and commercialised it, later developing tightening devices for it. In August 1960 it built the Oni factory in Kumasaka, Shuzanji-cho, Tagata-gun, Shizuoka Prefecture. In October 1962 the company was renamed Ihara High Pressure Fittings Industry Co., Ltd. (伊原高圧継手工業株式会社), reflecting its status as a brand manufacturer; the bite-type fitting had by then been standardised as a JIS product. In June 1963 the company increased its capital to 110 million yen and listed its shares on the over-the-counter market (the predecessor of JASDAQ), and it introduced a distributor system, signing Nakanishi Shoji as its first distributor. The company's own history page divides its development into four "foundings" (第1創業 through 第4創業), with the first spanning 1941–1961 and the second beginning in 1962. Over the following decades it expanded from hydraulic fittings into valves, hoses, pipes and complete piping systems, and organised its business into the General Piping (GP) Division and the Clean Piping (CP) Division. The GP Division serves general industrial piping for oil, air, water, steam, high-viscosity fluids and gas, with applications in construction machinery, machine tools, shipbuilding, railway vehicles and other industrial machinery. The CP Division serves clean fluid piping for high-purity gas and liquid, pharmaceuticals, food and pure water, with applications in semiconductors and LCDs, energy, food and medical markets, and analytical and measuring instruments. The company operates sales offices in Tokyo (East Japan), Nagoya (Central Japan) and Osaka (West Japan), and manufacturing sites including the Izu-Nagaoka and Naka-Izu plants in Shizuoka, the Yamagata plant, and the Gifu plants (Tsukeji No. 1 and No. 2, and Ena-Kita). Group companies include Yamagata Ihara Co., Ltd. in Japan, Ihara Science USA Corporation with offices in Irvine, California and Meadville, Pennsylvania, Ihara Science Taiwan Co., Ltd. in Taichung, and Nantong Ihara Science Co., Ltd. in Nantong, Jiangsu, China, which operates both GP and CP plants. The company states that it operates globally with bases in Japan and around the world. Recent corporate news includes a change of fiscal year-end and partial amendment of the articles of incorporation announced in December 2024, a capital reduction announced in April 2024, and notices in 2025 concerning a merger, changes to officers and changes to the corporate number and invoice number.

• 2025

  Announces merger-related notices on officer structure, corporate number and invoice number.

• 2024

  Announces capital reduction (April) and change of fiscal year-end and partial amendment of articles of incorporation (December).

• 1963

  Lists shares on the over-the-counter market (predecessor of JASDAQ); signs Nakanishi Shoji as first distributor.

• 1962

  Renamed Ihara High Pressure Fittings Industry Co., Ltd.

• 1960

  Builds Oni factory in Shizuoka; encounters bite-type fitting in transaction with Mitsubishi Heavy Industries.

• 1959

  Masaru Ihara joins; annual sales surpass 100 million yen.

• 1958

  Joins the Hydraulic Equipment Industry Association (now Fluid Power Industry Association).

• 1953

  Begins operating as a manufacturer of high-pressure fittings for piping.

• 1952

  IS brand created, marking transition from trading house to manufacturer.

• 1947

  Incorporated as Ihara Sangyo Co., Ltd. with capital of 50,000 yen.

• 1941

  Masaji Ihara founds Ihara Shokai in Shibahamamatsu-cho, Minato-ku, Tokyo.

Specialist manufacturer of high-pressure fittings and total optimal piping systems, spanning general industrial and clean/high-purity fluid applications.

• Kuikomi tsugite (bite-type fitting)

  Core product; a flareless fitting for high-pressure hydraulic piping, standardised as JIS.

• Valves

  Valves for general and clean piping applications.

• Hoses and pipes

  Hoses and pipes for fluid transport.

• Clean piping components

  Components for high-purity gas and liquid, pharmaceutical, food and pure-water applications.

• Optimal Piping System

  Total piping solution covering design, machining, assembly and maintenance.

1. 1ホーム | イハラサイエンス株式会社ihara-sc.co.jp
2. 2沿革 | イハラサイエンス株式会社ihara-sc.co.jp
3. 3企業理念 | イハラサイエンス株式会社ihara-sc.co.jp
4. 4営業所・事業所・グループ企業 | イハラサイエンス株式会社ihara-sc.co.jp
5. 5Ihara Science Corporation (Japan) - Wikidatawikidata.org