| 1950-08 |
Established 'Iwabuchi Electric Equipment Co., Ltd.' at 4-4, Kiba-cho, Chuo-ku, Tokyo with a capital of 1 million yen. |
| 1951-02 |
Commenced sales of overhead line fittings and related items to Japanese National Railways (now JR companies) and private railways. |
| 1952-09 |
Changed company name to 'Iwabuchi Metal Industry Co., Ltd.' |
| 1955-04 |
Established substation rod specifications at Chubu Electric Power Co., Inc. |
| 1955-10 |
Established a Nagoya branch office (now Nagoya branch) in Nagoya City. |
| 1955-12 |
Specified substation rods at Tokyo Communication Bureau (now NTT). |
| 1957-03 |
Specified ISR-Ⅱ (GYR) substation rods at Tokyo Electric Power Co., Inc. |
| 1957-05 |
Specified ISR-Ⅱ substation rods at Kansai Electric Power Co., Inc. South Branch. |
| 1958-04 |
Specified various flexible bands (IBA, IBB, IBC, etc.) at Tohoku Electric Power Co., Inc. Yamagata Branch. |
| 1959-02 |
Established an Osaka branch office (now Osaka branch) in Osaka City. |
| 1961-09 |
Specified substation rods at Kyushu Electric Power Co., Inc. |
| 1962-01 |
Specified substation rods at Chugoku Electric Power Co., Inc. |
| 1962-05 |
Constructed Matsudo factory (now Matsudo headquarters) at 167 Kamihongō, Matsudo City. |
| 1964-01 |
Specified substation rods at Shikoku Electric Power Co., Inc. |
| 1965-03 |
Specified flexible C-band (IBT) at Hokkaido Electric Power Co., Inc. |
| 1965-04 |
Opened the Sendai Branch Office (now Sendai Branch) in Sendai City. |
| 1965-08 |
Opened the Sapporo Sales Office (now Sapporo Branch) in Sapporo City. |
| 1966-07 |
Specified the line pole (GYR) at Hokuriku Electric Power Co., Ltd. |
| 1968-01 |
Established the plating division as "Iwabuchi Plating Industry Co., Ltd." and the plastic division as "Iwabuchi Plastic Industry Co., Ltd." |
| 1969-08 |
Established Iwabuchi Kankou Co., Ltd. for the welfare of Iwabuchi Metal Industry and its affiliated companies. |
| 1970-09 |
Opened the Fukuoka Sales Office (now Fukuoka Branch) in Fukuoka City. |
| 1971-05 |
Constructed Matsudo North Factory (now Matsudo Factory) at 241 Nakane, Matsudo City (currently 176 Nagatsucho, Nakane, Matsudo City, Chiba Prefecture). |
| 1974-07 |
Built the Sendai Branch Office building in Miyagino-ku, Sendai City. |
| 1976-06 |
Expanded Matsudo North Factory and consolidated the production lines of Matsudo Factory. |
| 1979-04 |
Opened the Hiroshima Sales Office (now Hiroshima Branch) in Hiroshima City. |
| 1986-08 |
Changed the company name to "Iwabuchi Co., Ltd." |
| 1986-08 |
Absorbed and merged "Iwabuchi Plating Industry Co., Ltd." |
| 1988-09 |
Established the mold manufacturing division as "Iwabuchi Mechanics Co., Ltd." |
| 1995-04 |
Registered the company's shares with the Japan Securities Association. |
| 1999-11 |
Obtained ISO 9001 certification. |
| 2000-04 |
Absorbed and merged "Iwabuchi Mechanics Co., Ltd." |
| 2001-08 |
Specified the scaffolding fastener band (IBT) at Okinawa Electric Power Co., Ltd. |
| 2001-10 |
Obtained ISO 14001 certification. |
| 2002-03 |
Consolidated the Tokyo headquarters to Matsudo headquarters. |
| 2002-06 |
Updated to ISO 9001:2000 version. |
| 2002-09 |
Established Haiyang Yanfen Metal Products Co., Ltd. in Haiyang City, Shandong Province, China. |
| 2003-03 |
Constructed the Nagoya branch office building in Naka-ku, Nagoya. |
| 2004-10 |
Absorbed and merged Iwabuchi Kankou Co., Ltd. (formerly Iwabuchi Kankou Co., Ltd.) |
| 2004-12 |
Cancelled over-the-counter registration with the Japan Securities Association and listed on the JASDAQ Stock Exchange. |
| 2005-12 |
Updated to ISO14001:2004 version. |
| 2006-01 |
Constructed the Osaka branch office building in Yodogawa-ku, Osaka. |
| 2007-09 |
Expanded the Matsudo Distribution Center. |
| 2009-07 |
Haiyang Yanfen Metal Products Co., Ltd. obtained ISO14001:2004 certification. |
| 2009-07 |
Constructed the Sapporo branch office building in Shiroishi-ku, Sapporo. |
| 2009-10 |
Haiyang Yanfen Metal Products Co., Ltd. obtained ISO9001:2008 certification. |
| 2009-12 |
Updated to ISO9001:2008 version. |
| 2010-04 |
Listed on the Osaka Stock Exchange JASDAQ market following the merger of the JASDAQ Stock Exchange and the Osaka Stock Exchange. |
| 2010-09 |
Absorbed and merged Iwabuchi Chemical Co., Ltd. (formerly Iwabuchi Plastic Industry Co., Ltd.) |
| 2011-09 |
Constructed Matsudo Plant 2 at 138-1 Kamihongo, Matsudo City. |
| 2012-01 |
Constructed the Shirahama Exposure Test Site in Shirahama Town, Minamiboso City. |
| 2013-05 |
North Seiko Ironworks Co., Ltd. (now HOKUEI Co., Ltd.) in Ishikari City, Hokkaido, became a group company. |
| 2013-07 |
Listed on the Tokyo Stock Exchange JASDAQ Standard market following the integration of the Osaka Stock Exchange and the Tokyo Stock Exchange's physical market. |
| 2015-10 |
Established IWM Co., Ltd. in Higashi-ku, Nagoya, Aichi Prefecture. |
| 2016-10 |
Stock consolidation (10 shares into 1 share) and change of unit share quantity (from 1,000 shares to 100 shares). |
| 2017-05 |
Kyowa Kogyo Co., Ltd. in Konohana-ku, Osaka became a group company. |
| 2017-07 |
Established the Iwabuchi Technical Center (ITC) |
| 2018-01 |
Updated to ISO 9001:2015 and ISO 14001:2015 |
| 2022-01 |
Suda Seisakusho Co., Ltd. (Chuo-ku, Tokyo) became a group company |
| 2022-04 |
Transitioned to the Standard market as part of the move to the new market classification of the Tokyo Stock Exchange |
| 2024-07 |
Absorbed Tomita Steel Co., Ltd. (Matsudo City, Chiba Prefecture) |
