1925
Kaneo Oku founds a business selling iron wire and nails at 9 Unagidani Higashino-cho, Minami-ku, Osaka.
1945
Begins manufacturing wire nails, special nails, and iron wires at 12-25 Higashiyama-cho, Higashiosaka.
1949
Changes structure from private management to incorporated status. Okukane Tessen Co., Ltd. begins manufacturing iron wire to screw specifications. Capital of ¥3.0 million.
1965
Takao Oku succeeds as president.
1972
Merges with Kawakin Kogyo Co., Ltd., and changes trade name to O&K Limited. (Capital: ¥38.0 million)
1974
O&K Sales, Inc. is founded as a fully-owned subsidiary of O&K Limited. (Capital: ¥10.0 million)
1979
Founds a plant in Kanaoka Tobishima-mura, Ama-gun, Aichi; operations begin at the Nagoya Plant.
1980
Establishes O&K Steel (USA), Inc. in Illinois, USA for market research and to streamline exports. In addition, production facilities are installed and production commences in the USA.
1981
Acquires 52% of Settsu Tessenn Co., Ltd. (2-8-81 Nakajima, Nishiyodogawa-ku, Osaka; Capital: ¥80.0 million) shares from ITOCHU Corporation and becomes involved in management, changing the trade name to O&K Steel Co., Ltd. and starting operation at the O&K Osaka Plant in Apr. 1982.
1982
Increases capital to ¥50.0 million.
1985
Acquires all shares from Wire Sales Company, a local wire manufacturer in Illinois, USA.
1991
Transfers administrative functions to the office at the Osaka Plant, making this the Operational Headquarters.
1993
Founds a plant in Yabuzuka Honmachi, Nitta-gun, Gunma; operations begin at the Gunma Plant.
1996
The entire company obtains ISO 9002 (Certification No. JQA-1250) certification.
1997
O&K Osaka Test Center obtains ISO/IEC 17025 (Certification No. 200166-0) certification, the first company in Japan to do so.
1997
Kobe CH Wire (Thailand) Co., Ltd. is founded jointly in Thailand (Capital participation: 11%).
2000
The entire company obtains ISO 14001 (Certification No. JQA-EM0555) certification.
2001
The Western Division obtains QS-9000 (Certification No. JQA-QS0150) certification.
2002
Capital participation in Kobe CH Wire (Thailand) Co., Ltd. increases to 25% through share acquisition.
2002
Establishes OKUKANE Corporation for the purpose of making the technical development and assistance department an independent entity.
2003
Certification changes from ISO 9002 to ISO 9001:2000.
2004
The entire company obtains ISO/TS 16949 (Certification No. JQA-AU0061) certification.
2005
O&K American Corp. obtains ISO/TS 16949:2002 (Certification No. OY801-TSI) certification.
2007
Obtains Authorized Exporter (Accreditation No. E4070002) accreditation.
2007
Purchases all O&K Steel Co., Ltd. shares, making it a fully-owned subsidiary.
2008
Kazuta Oku is promoted to President.
2010
Merges O&K Steel Co., Ltd.
2010
O&K American Corp. establishes its 2nd plant in Seymour, Indiana, USA.
2013
O&K Osaka Test Center accredited under ISO/IEC 17025 (Accreditation No. RTL03650) by JAB.
2018
The entire company obtains IATF 16949 (Certification No. JQA-AU0061) certification.
2025
Marks 100th anniversary of the inauguration of business in Jan.