1942Akio Okamoto establishes a piping and plate working business
1948Okamoto Industries, Co., Ltd. is established in Ooi Kurata-cho, Shinagawa-ku, Tokyo and the Plant Facility Construction business begins operation
1959Maintenance and Production Support business is launched
1970The Precision Machinery Division (the current FA Business Division) is newly established, and the Transport Equipment Manufacturing business is launched
1988The Plant Facility Construction Division and other divisions are split into Okamoto Industries, Co., Ltd. while the Transport Equipment Division related departments are split into Okamoto Systems Co., Ltd.
1990The Fukushima Plant (the current Hanawa Plant No. 1 ) is newly established, and the Precision Metal Processing business is launched
1994Okamoto Systems Co., Ltd. establishes IO Systems Ltd. in Ireland
2012Okamoto Industries, Co., Ltd. and Okamoto Systems Co., Ltd. are merged
2017Head Office is relocated to Higashi-shinagawa, Shinagawa-ku, Tokyo