Company Profile Here is an overview of Okudasokabe's business activities.

Company policy


As “Technical OSK”, our company implements the company credo “enthusiasm, ingenuity, sincerity” every day, as our goal to become NO. 1 manufacturer in the world of metallic bellows type expansion joint with great trust of customers in both quality and performance, our basic cooperation policy is to promote the following.

Okuda Sogabe Co., Ltd.
  • 1. To continuously innovate both in terms of management and technology to respond to changes in the industrial structure.
  • 1. To contribute to society by continuously improving quality and performance.
  • 1. To contribute to society with gratitude, always devoting ourselves and improving the welfare of our employees.

Greeting from the President

Okuda Sogabe Co., Ltd. (OSK) has been manufacturing metallic bellows type expansion joints serving for piping in not only infrastructures and lifelines such as electric power, gas, water supply and sewerage in the public works field, but also key industrial fields such as refineries, petrochemicals, steel milling, shipbuilding and heat supply facilities of the distinct heating and cooling system for the urban environmental improvement since the establishment of 1925.
Furthermore, we continuously supply expansion joints for hazardous storage facilities and pressure vessels etc.
Aiming at becoming the No. 1 manufacturer in the world of bellows type expansion joint, we are proud of delivering “the best products with economically reasonable price evaluated based on the highest quality and the long service life, even though it might be at the highest price in the world.” All employees are making efforts to contribute to the company to respond to severe international liberalization with the highest priority, continuously developing new technologies and keeping on quality assurance activities and then ask for your continuous support and encouragement accordingly.

Company Profile

Company Name Okuda Sogabe Co., Ltd.
Business started March 27, 1925
Established June 7, 1952
HQ Address 3 Konoike Tokuan-cho, Higashiosaka-shi, Osaka, 578-0977 Japan
Representative President, Yasuyuki Okuda
Capital 30,123,000 Japanese Yen
Number of Employee 120
Our bank Sumitomo Mitsui Banking Corporation, MUFG Bank, Ltd. Mizuho Bank, Ltd.

Applicable laws and standards, certificate and qualification

  • Electricity Business Act (Nuclear Power)
  • Electricity Business Act
    (Thermal Power: Heat Exchanger, Boiler, Liquified Gas Facility & Site Work etc.)
  • High Pressure Gas Safety Act
    (Designated equipment, Commissioned Inspection, General HPG Equipment)
  • Gas Business Act
  • Heat Supply Business Act
  • Construction Code for Boiler
  • Construction Code for Pressure Vessels (Class-1, Cass-2)
  • Fire Service Act
  • “Process Certification I (including site work) as per “TNS-S3101-2017”, which is Quality requirements for fusion welding metallic materials on JIS Z3400.
  • Certificate of Factory of Welding and Fabrication for Nuclear Fuel Material, Nuclear Fuel Material and Nuclear Reactor Facility


Tokyo Office

Address: 39-5 Kameido 2-Chome, Koto-Ku, Tokyo 136-0071, Japan.

3rd Sales Dept.
Overseas Sales Group

TEL +81-3-3685-0311, FAX +81-3-3685-8836

Nara office/factory

Address: 2360 Kita-Tahara-Cho, Ikoma City, Nara 630-0142, Japan

General Affairs Dept.

Order Management Dept.

1st Sales Dept.

1st Manufacturing Dept.

Quality Assurance Dept.

Okayama office/factory

Address: 8255 Shin-Minato, Tamashima-Otoshima, Kurashiki City, Okayama 713-8103, Japan

Quality Assurance Dept.

2nd Sales Dept.

Technical Dept.

2nd Manufacturing Dept.

Company History

March 1925 Okuda Iron Works was established
January 1927 Sogabe Shoten Co., Ltd was allied with Germany Badel unto Harbig Co.,Ltd and became the sale agent in Japan.
March 1933 Domestic flexible tubes were successfully produced. Okuda Iron Works for “Manufacturing” and Sogabe Shoten Co., Ltd. for “Sales” had a business alliance.
June 1951 Okuda Iron Works and Sogabe Shoten Co., Ltd were Merged and Okuda Iron Works, Sogabe Shoten Co., Ltd. was established.
August 1960 The head office and factory moved from Osaka City to Higashiosaka City to be expanded and started the intensive production
October 1961 The factory was certified in compliance with weld procedure standard under the Electricity Business Act (Thermal Power), the Ministry of International Trade and Industry.
January 1964 The company name was changed to Okuda Co., Ltd. for Manufacturing and Okuda Sogabe Co., Ltd. for “Sales”.
January 1969 Nara Factory was established in Ikoma-city, Nara-Prefecture.
March 1970 The manufacturing License under Pressure Vessel Class-1, the Ministry of Labor, was acquired.
September 1971 A project team for nuclear power was organized to enter the nuclear power field
January 1972 The factory was certified under the Electrical Business Act (Nuclear Power), Ministry of Iinternational Trade and Industry.
September 1981 The largest in the world 27-meter-diameter nuclear containment vessel DF seal bellows was delivered to Tokyo Electric Power Company (TEPCO).
June 1984 Okuda Co., Ltd. for “Manufacturing” and Okuda Sogabe Co., Ltd. for “Sales” was integrated into Okuda Sogabe Co., Ltd.
April 1994 Okayama Rinkai factory was established in Kurashiki City, Okayama Prefecture.
January 1995 The National Commendation of “the Small and Medium Enterprise Research Center Award” was received, recommended by the Ministry of International Trade and Industry, the Agency of Science and Technology, and the Chamber of Commerce and Industry.
October 2005 “Certificate of Welding Management Process” was acquired under the Electricity Business Act as for pipes and vessels related to thermal power plants and fuel cell power plants.
July 2011 The NARA factory was expanded and the entire renovation work was completed.
February 2013 Osaka Factory & office were transferred and consolidated into Nara factory
May 2019 The inspection building of the 1st manufacturing department were extended
December 2021 Acquisition of “Process Certification I (including site work) in accordance with “TNS-S3101- 2017” which is a Certification Standard (Thermal Power) for fusion welding metallic materials of JIS Z3400.