- Sumida is one of the leading manufacturers of coils and wire wound electronic products. Sumida currently has over 31000 products in its coil catalog-attesting to the diversity to which coil technology can be applied in the present day information age. All of Sumida's products are manufactured outside of Japan in various locations in the Asian region as well as in Mexico. This has allowed Sumida to keep costs to a minimum, spread risk and increase response times.