| May 1950 |
Daido Heat Treating Company is founded at 359 Yukigaya, Ota Ward, Tokyo. |
| August 1951 |
Ohya Heat Treating Company is established. |
| March 1952 |
Receives designation from the former Ministry of International Trade and Industry as a certified factory for calibration tools. |
| April 1953 |
High frequency hardening division commences operations. |
| March 1954 |
Relocates offices and facilities to 2-18-12 Nakaikegami, Ota Ward, Tokyo. |
| December 1958 |
Launches shift of carburized quenching method from the solid carburizing to the gas carburizing method (fully completed in October 1965). |
| April 1961 |
Receives a research grant from the former Ministry of International Trade and Industry to conduct a study on high temperature gas carburizing, and presents its findings on March 20, 1962. |
| June 1967 |
Acquires site for a plant in the Nairiku Industrial Park located in Kanagawa Prefecture. |
| April 1968 |
Atsugi Plant commences operations. |
| May 1969 |
Acquires site for a plant in Kitasaitama County, Saitama Prefecture. |
| September 1969 |
Kisai Plant commences operations. |
| April 1971 |
Launches technology development activities after establishing a research laboratory staffed with full-time researchers. |
| April 1971 |
Establishes research laboratory for the research and development of metal heat treatment technologies (currently, Research Institute of Technology). |
| January 1972 |
Establishes Ohya Transportation Company (currently, ONEX Line Corporation) |
| March 1973 |
Relocates head office to 2-14-5 Nakaikegami, Ota Ward, Tokyo. |
| December 1973 |
Acquires site for a plant in Sanyo Town, Asa County, Yamaguchi Prefecture. |
| September 1974 |
Establishes Light Alloy Department in the Atsugi Plant and commences heat treatment of non-ferrous metals. |
| January 1975 |
Makes capital investment in the Small and Medium Business Investment & Consultation Co., Ltd. |
| April 1975 |
Changes research laboratory into research institute. |
| September 1976 |
Yamaguchi Plant commences operations. |
| October 1976 |
Relocates head office to 3012-3 Uenohara Kamiechi, Atsugi City, Kanagawa Prefecture. |
| June 1978 |
Establishes Ohya Engineering Company (currently, ONEX Engineering Corporation) |
| December 1978 |
Acquires site for a plant in the Higashi Matsuyama Industrial Park located in Saitama Prefecture. |
| July 1980 |
Higashi Matsuyama Plant commences operations. |
| October 1984 |
Spins off the Yamaguchi Plant and establishes new company Sanyho Ohya Heat Treating Company (currently, Yamaguchi Plant, ONEX Corporation). |
| December 1985 |
Head Office Plant approved as Japanese Industrial Standards (JIS) designated factory. |
| January 1986 |
Installs and commences operations of the ONEX Fine Coating Machine at the Head Office Plant. |
| January 1986 |
Acquires site for a plant in Ueda City, Nagano Prefecture. |
| December 1986 |
Higashi Matsuyama Plant approved as a Japanese Industrial Standards (JIS) Mark Certified Factory under the Old JIS Mark Certification Scheme. |
| November 1987 |
Makes capital investment in Shinano Metallurgy Company and changes its name to Nagano Oyhya Heat Treating Company (name changed shortly thereafter to ONEX Nagano Company ). |
| August 1989 |
Relocates and integrates all equipment and facilities from the Kisai Plant to the Higashi Matsuyama Plant. |
| July 1991 |
Changes name from Oya Netsushori Co., Ltd. to ONEX Corporation in order to unify its brand identity across its entire group of companies. |
| October 1991 |
Relocates ONEX Nagano Co., Ltd. (currently, Nagano Plant) to the Shioda Industrial Park located in Ueda City, Nagano Prefecture. |
| June 1992 |
Increases capital through allocation of new shares to a third party at market price. |
| May 1994 |
Establishes and commences operations on the bright division in the No. 2 Plant. |
| February 1997 |
The Company's shares are listed on the OTC market. |
| October 1998 |
ONEX Yamaguchi Company (currently, Yamaguchi Plant) receives ISO 9002 certification. |
| March 2000 |
Dissolves ONEX Nagano Company, making it the Nagano Plant. |
| August 2000 |
Higashi Matsuyama Plant receives ISO 9002 certification |
| December 2000 |
Atsugi Plant receives ISO 9002 certification. |
| May 2002 |
Head Office Plant and No. 2 Plant merge to become part of the Atsugi Plant. |
| January 2004 |
Merges through absorption with ONEX Yamaguchi Co., Ltd., making it the Yamaguchi Plant. |
| April 2005 |
Atsugi Plant receives ISO 14001 certification. |
| September 2005 |
Higashi Matsuyama Plant receives ISO 14001 certification. |
| April 2006 |
Nagano Plant receives ISO 9001 certification. |
| July 2006 |
Acquires site for a plant within the Shin-Yamanoi Industrial Park located in Sanyo-Onoda City, Yamaguchi Prefecture. |
| February 2007 |
Yamaguchi No. 2 Plant commences operations. |
| April 2010 |
Lists its shares on the JASDAQ Market of the Osaka Securities Exchange after the JASDAQ Securities Exchange and Osaka Securities Exchange merge. |
| July 2013 |
Lists its shares on the JASDAQ Market of the Tokyo Stock Exchange after the Tokyo Stock Exchange and Osaka Securities Exchange merge. |
| December 2013 |
Acquires ISO/TS16949 certification from Bureau Veritas Quality International for its quality management system for automotive components at the Atsugi Plant and Higashi Matsuyama Plant. |
| May 2014 |
Establishes ONEX Tech Center Corporation. |
| September 2015 |
The Vacuum Division in Atsugi Plant receives JIS Q 9100:2009 certification from BUREAU VERITAS (BVQI) |
| December 2015 |
ONEX Tech Center Corporation Mie Plant commences operation |
| December 2015 |
ONEX Mie Office opens |
| March 2016 |
ONEX Line Corporation Mie Office opens |
