Sosin Co., Ltd.

Established Kawa Manufacturing Co., Ltd. with a capital of 600,000 yen

Renamed to Kawa Seiki Co., Ltd. and solidified corporate foundation with support from Hino Motors

Started development, production, and sale of trailer couplers

Relocated factory from Itabashi, Tokyo to Kawagoe, Saitama

Entered technical partnership with Holland Hitch Co., USA for trailer couplers and began production and sales of the same model

Started development, production, and sale of trailer axles and suspension devices

Merged with Chiyoda Automobile Industries Co., Ltd., a domestic equipment manufacturer, and formed Sosin Co., Ltd. (Domestic Equipment Co., Ltd. founded August 1926; Chiyoda Automobile Industries founded December 1945)

Initiated ISO 14001 certification activities at Tamagawa Factory (certified February 2002)

Initiated ISO 14001 certification activities at Headquarters & Iruma Factory (certified March 2003)

Transferred 2-ton deck production equipment from Hino Motors & Hamura Factory

Expanded press factory and built a third factory

Introduction of press business by Musashi Press Industry Co., Ltd.

Start of wooden deck production

Completion of new paint factory

Start of assembly and painting production of 1.5t steel deck

Start of assembly and painting production of 0.75t steel deck

Start of production of small truck fuel tanks (1.5t to 2.0t)

Contract of technical assistance with Thai TRM Co.

Contract of technical assistance with Indonesian MTG Co.

Celebration of 10th anniversary: start of air tank production under technical assistance contract with Thai TRM Co.

Start of water pump production under technical assistance contract with Indonesian MTG Co.

Expansion of 1F floor of Inma Building 1

Addition of continuous 3rd furnace for carburizing heat treatment line

Start of production of aluminum fuel tanks

Start of import of elbows in Indonesia

Becomes a 100% subsidiary of Hino Motors, Ltd.

Transfer of oil pan painting

Start of production of differential parts

Start of production of through shafts

Celebration of 15th anniversary

Renovation of both factories, conference rooms, multipurpose hall, and employee cafeteria

Mirror Stage Production Commencement

Expansion of Continuous 4th Furnace for Carbonization in Heat Treatment Line

Absorption Merger with Subsidiary, Seiji K. Co., Ltd.

Large Brake Drum (Rear) Production Commencement

Solar Power Generation Implementation

Brake Camshaft Production Commencement

Axle Pipe Production Commencement

Large Brake Drum (Front) Production Commencement : Type Brake Drum (Rear) Production Commencement

Expansion and Renovation of Building 3 in Iruma

Large Special Axle Production Commencement

Dead Axle Tube S/A Production Commencement

Iruma Logistics Center Completion

Medium and Small Hub & Hub Drum Production Commencement

Celebrating 20th Anniversary of Founding

Large Hub Drum Production Commencement

Automation of Aluminum Air Tank

Renovation of 1st Floor Office in Building 1, Iruma

Renovation of 2nd Floor Office in Building 2, Tamagawa

Large Propeller Shaft Production Commencement

Renovation of 1st Floor Cafeteria in Building 2, Iruma

Newly established Niren factory (building area: 5,572.14 m²) in Koriyama City, Ibaraki Prefecture

Obtained certification as a health‑promoting company "Silver"