Head Office & Tsukuba Plant	1158, Takamori, Sakuragawa, Ibaraki 309-1297, Japan Tel. 0296-58-5161 (key)　 Fax. 0296-58-5722

Sales Division	4F, Akihabara center place Bldg.,1, Kandaaioi-cho, Chiyoda-ku, Tokyo 101-0029, Japan Tel.03-6854-1481  Fax.03-6854-1484

Osaka Sales Office	9F, Shin-Osaka Daiichi Seimei Bldg., 5-24, Miyahara 3-chome, Yodogawa-ku, Osaka 532-0003, Japan Tel. 06-6350-5691  Fax. 06-6350-5696

1960	Yamamoto Hatsujo Bunki, Inc. (founded in 1908) and Nitto Industries, Inc. were merged together, and Sumikin Hatsujo Co., Ltd. was formed as an affiliate of Sumitomo Metal Industries, Ltd. Head Office: Amagasaki Capital: 190 million yen
1965	Head Office moved to Fujisawa City. Acquired Nitto Industries, Inc. and Amagasaki Factory was opened. Capital: 200 million yen
1970	Factories were united in Fujisawa Factory. Capital: 300 million yen
1975	NHK Spring Co., Ltd. acquired shares from Sumitomo Metal Industries, Ltd. and company name was changed to Sumihatsu Co., Ltd.
1978	Acquired Nikken Spring, Inc., an affiliate of NHK Spring Co., Ltd. Capital: 345 million yen A new factory for spring clips was completed in the corner of in the Industrial Complex at Yamato-mura, Ibaraki.
1981	Closed Fujisawa Factory. Completed a complete transfer from Fujisawa to establish our Tsukuba Plant.
1982	Completed production facilities for automobile coil springs.
1983	Moved Head Office to Iwamoto-cho, Chiyoda-ku, Tokyo.
1995	Established Sumihatsu Service Co., Ltd. as an affiliate.
1997	Manufacturing of Balancer Assy was started. Business cooperation agreement was signed with Pandrol Track Systems Ltd.
1998	Started full-scale production of the Pandrol clips.
1999	ISO 9001 was certified (leaf spring, C2)
2000	ISO 9001 was certified (industrial machinery, railways). Sumihatsu Service Co., Ltd. started elderly care business.
2001	Started production of synthetic sleepers.
2002	Ended production of coil springs of automobiles.
2003	Signed an agreement to make rail fastening devices for the Taiwan Shinkansen. All shares owned by Sumitomo Metals (Kokura), Ltd. were transferred to NHK Spring Co., Ltd. ISO 14001 was certified.
2007	Installed LNG satellite equipment. Enlarged the building of the second leaf spring plant.
2009	Started receiving full-scale orders of torsion bars for railway vehicles.
2015	Started Sumihatsu Service Co., Ltd. outpatient care (day service) business.
2020	Moved our Head Office to Sakuragawa City, Ibaraki Prefecture.
2023	Moved Sales Division to Kandaaioi-cho, Chiyoda-ku, Tokyo.