December 1946

The founder Mr. Soichiro Yamashita established "Ko-ken Tool Company"

August 1959

Reorganized into Ko-ken Tool Co., Ltd.

February 1962

M.I.T.I. recognized the license of J.I.S. marking and shown on the Ko-ken products.

November 1965

Started direct export business.

February 1973

Started to exhibit at the Cologne Fair, in Germany .

May 1973

Factory and office were moved to 656 Nakaho, Daito-cho (Kakegawa)

August 1984-87

Exhibited at Chicago Hardware Show, in USA .

June 1991

S.O.D.H. System was adopted for reversible ratchets.

April 1995

Heat treatment plant was renewed.

November 1995

The first Japanese tool manufacturer to obtain ISO 9002 Certification.

June 1997

Parts-former plant was built to install new forming machines.

June 1999

Obtained ISO9001 Certification.

October 2007

Used as official socket wrench at WorldSkills Competition.