Since its founding, KOUEI has been supplying high temperature / corrosion resistant alloys, magnetic materials, low-expansion alloys (Kovar, Invar), electronic metal parts and various special alloys to many different fields such as petrochemical, industrial machine, heat exchanger, electronics industry, marine development, electric power, aerospace industry and other industries.
At first, we delivered raw materials in a shape of wire, bar, sheet, pipe and strip, and gradually as responding to various demands, we have been supplying processed parts in many opportunities. Today, we also design and manufacture various industrial machineries and plant equipment.
Regarding to processing way for special metal alloys, there are variety of problems like poor machinability, difficult plasticity, specific heat treatment specification and special welding techniques.
We have improved and researched these processing techniques and application of the materials for a long time. And more, we have established network of cooperative factories.
In 2009, we opened a factory for rolling and heat treatment of strips, and for development of clad metals. The factory can answer to customer’s requests such as small amount of custom-made products or from trial production to mass production.
In the field of advanced technology development, special alloys are playing an important role increasingly large every year.
KOUEI will contribute to development of technology through supplying highly- functional materials.

President Kazuhiro Yamaguchi

About us

HQ main building HQ new building
(H.Q. Main building)    (H.Q. New building)
Company name KOUEI CO., LTD.
Foundation March 1977
Establishment October 1978
Capital 48,000,000 JPY
Services Design and production of precious metal contacts materials

Processing of metal materials, design and production of machineries

Number of employees 94(include director)
Fiscal term March 31st

■New Building
3-5-4, Chuo, Edogawa-ku, Tokyo, JAPAN 132-0021

■Main Building
3-5-6, Chuo, Edogawa-ku, Tokyo, JAPAN 132-0021

Strip Sales Dept. +81-3-3674-5221

Functional materials Dept. Material Gr. +81-3-3674-5222

Functional materials Dept. Precision parts Gr. +81-3-3674-5203

Technical Sales Dept. +81-3-3674-5223

International Sales Dept. +81-3-5879-9927

FAX +81-3-3656-0503


■Kansai Branch

2F, Akashiya Building, 2-5-13, Koraibashi, Chuo-ku, Osaka City, Osaka, JAPAN 541-0043


FAX +81-6-6786-8151

■Inspection Building

3-6-1, Chuo, Edogawa-ku, Tokyo, JAPAN 132-0021

■Edogawa Warehouse

3-6-14, Chuo, Edogawa-ku, Tokyo, JAPAN 132-0021

■Saitama Factory

1450-10, Ohmidoh, Kamisato-Machi, Kodama-Gun, Saitama, JAPAN 369-0315




1977. 3 Founded in Higashi-mizue, Edogawa-ku
1978. 12 Moved to Matsue, Edogawa-ku
1988. 9 Moved to Chuo, Edogawa-ku
1990. 3 Opened a warehouse in Koiwa, Edogawa-ku
1992. 10 Opened a warehouse in Ohsugi, Edogawa-ku
1995. 6 Consolidated warehouses in Ohsugi, Edogawa-ku
1997. 7 Moved office to current address
2002. 1 Moved warehouse to Chuo, Edogawa-ku
2005. 12 Certified ISO 9001 (JAB, UKAS)
2009. 5 Opened Saitama Factory and Saitama Office
2013. 5 Certified ISO 14001 (JAB, UKAS)
2020. 10 Headquarter New Bldg. Completion
2021. 7 Kansai Branch opened