Ko-ken Tool Co., Ltd. Japan

Ko-ken Tool Co., Ltd. headquarters and Manufacturing plant is located at Kakegawa-City, Shizuoka-Pref., Japan. Founded by Mr. Soichiro Yamashita in 1946. The Company has continually grown with its focus on producing high quality socketry, Globaly recognised as one of the highest quality manufacturers. with a workforce of over 130 Ko-ken products are designed and manufactured using the latest technologies to deliver the highest quality and most modern designed tools.


The 3D-CAD is used to improve standard
products, designing new products and making
customized items for special requirements.
Trial products are regularly developed,
manufactured and tested to improve the
durability, appearance and functionality of all
tools produced by Ko-ken.

Ko-ken uses a variety of test equipment.
Strength is measured by the Static Load Test
Machine that can measure torque load up to
5,000Nm. Durability is measured by the Cyclic
Test Machine and corrosion resistance testing
is done by the Salt Spray Test Machine. The
test results are used to improve our standard
products and assist with new product design
and development.

The Forming machines are used for the forging
process. These machines can produce mass
quantities of sockets and parts with high
accuracy that ordinary drop forging machines
can not achieve. However, for small production
runs, ordinary forging machines are also used.

The forged steel is turned into required
shapes and dimensions. The MC (Machining
Center) operates with extraordinary speed
and precision. The article number, size, logo,
production number, and MADE IN JAPAN
are marked on the products after the turning
process has been completed.

To make the tools stronger and more durable,
proper heat treatment is critically important.
The temperature and the time of the heat
treatment are strictly regulated by a very
accurate control device.

Products are periodically checked at each
production process by inspection devices.
Highly accurate 3-D measuring instruments
are used to inspect and confi rm dimensions.

ISO 9001

Ko-ken Tool Co., Ltd., manufacturing processes have been certified in accordance with ISO 9001 since 1999. Ko-ken were the first Japanese tool manufacturer to obtain ISO 9002 Certification in Novenber 1995.