Sumitomo Electric Group History



The Sumitomo Electric Group

FOUR Centuries of Technical and Industrial Heritage underpinning 21st Century innovation

Established in the 16th Century in Japan, Sumitomo led the field, as early pioneers of the Japanese copper mining and refining industry. Today SEI stands proudly as a Global Leader of electrical technologies.

The long and illustrious history of Sumitomo, dates back to a family business founded by Masatomo Sumitomo, over four centuries ago and it was Masatomo Sumitomo himself (1585 – 1652), who created the long-enduring principles, of the Sumitomo Business Spirit, “Monjuin Shiigaki” which still today, underpin the strong business ethics and codes of practice.


Sumitomo House and Gardens, Kyoto

Yu-ho-en, Sumitomo House and Gardens, Kyoto


The name “SUMITOMO” has become synonymous with QUALITY and INTEGRITY.

These two principles, handed down over generations of the Sumitomo family, evolved to become the twin pillars of the business, upon which all Sumitomo group companies are built today.

1: Sumitomo shall achieve prosperity based on solid foundation by placing prime importance on integrity and sound management in the conduct of its business.

2: Sumitomo’s business interest must always be in harmony with public interest; Sumitomo shall adapt to good times and bad times but will not pursue immoral business.


In February 1917 Tokai Electric Wire Works to start manufacturing and sales of bare wires and shielded wires.  In July 1931 Tokai Electric Wire entered into a technical and capital alliance with Sumitomo Electric Wire and Cable Works (now Sumitomo Electric Industries Ltd.).  By 1957 the company had started to produce ARB – rubber insulated low-voltage wire designed specifically for the automotive industry.  Shortly after in May 1959, the company started the first wire harness production for two-wheeled vehicles.  The company expanded quickly and in 1967 new branches in Suzuka, Toykyo and Osaka were constructed.

In April 1985 the company changed the trading name to Sumitomo Wiring Systems, Ltd. and was listed on the Nagoya Stock Exchange in November 1986.  In May 1999, SWS acquired acquired Lucas SEI Wiring Systems Ltd in the UK and so Sumitomo Electric Wiring Systems – Europe (SEWS-E) was established.

We have in that time, cemented valuable relationships with our growing customer base and suppliers and have grown our business across more than 50 sites, throughout Europe and North Africa, employing 20,000 people.