- 1932
- Tomeichi Nakamura founded "Nakamura Welded Steel & Pipe Manufacturing
Co." at Taisho-ku, Osaka, Japan and started manufacturing and sales
of welded steel tubing.
- 1944
- The company was incorporated as Daiwa Steel Tube Industries Co., Ltd.
- 1970
- President Matsuichi Nakamura assumed office.
- 1973
- The first line of world patented "Daiwa Z Process" - a fully
automated in-line fabrication and hot-dip galvanizing system - was installed
in Sakai Plant.
Sales of "Post Zinc" started.
- 1977
- Head Office moved to Nakanoshima, Kitaku, Osaka, Japan.
Second line "Daiwa Z Process" was installed in Sakai Plant
- 1981
- Unity Corporation was established.
- 1987
- Kanto Plant was established in Tochigi Prefecture as the production base
in eastern Japan.
- 2003
- President Shinichiro Nakamura assumed office.
Daiwa Steel Tube Industries Co., Ltd. and Unity Corporation were certified
and registered as meeting ISO 9001 quality management system standards.
- 2004
- Sales of "Perfect Post Zinc" - steel tubing with hot-dip galvanized
interior and exterior - started.
Super Light 700, STX700, and STXR700 registered to NETIS (New Technology
Information System) by Ministry of Land, Infrastructure, Transport, and
Tourism.
- 2006
- Certified by New JIS (Japan Industrial Standard) Mark Certification Scheme.
- 2007
- 700N-level high-tensile steel tubing for structures was certified as Minister
of Land. Infrastructure, and Transport, and Tourism Approved Construction
Materials.
Headquarters function was moved to Tokyo Head Office.
East/West Japan Sales Headquarters were established.
- 2008
- Unity Corporation was renamed to DSTI Holdings Co., Ltd.
"Perfect Post Zinc" acquired Construction Technology Evaluation
Certification by Public Works Research Center.
- 2011
- Perfect Post Zinc registered to NETIS (New Technology Information System) by
Ministry of Land, Infrastructure, Transport, and Tourism.
Head Office was moved to Sakura-city , Tochigi.
Tokyo Sales Office was established in Chuo-ku,Tokyo.
