Contact Us

1100 McKinley Road
St Marys, OH 45885
P: 419-394-7840
F: 419-394-4776

Forty-Three Million Wheels...

A leader in the manufacture of
cast aluminum automotive wheels.

Our products can be found on some
of the most popular vehicles today.

Our clients include some of the largest
auto manufacturers in the world.

Quality in Every Phase

We are proud of our history and our capabilities in the design and manufacture of aluminum castings. Kosei is an American company, which enjoys the support of Kosei Aluminum Co., LTD. – a world leader in metallurgy and a wide variety of metal products. This relationship allows us to utilize the best of American and Japanese technology and management skill to produce the highest quality products.


“Continuous Improvement” is one of Kosei’s most important philosophies.  All of our processes, procedures, and programs are continuously evaluated to determine opportunities for improvement. All associates, regardless of position, are actively involved in supporting this philosophy, as well.  Our investment in training and development ensures formation of a strong team and helps us meet our goals.   We are constantly researching new manufacturing processes to give our clients the best product at the lowest price.



Environmental Policy

In the arena of environmental management, Kosei St. Marys (KSM) is committed to continuous improvement and will strive...

Corporate Social Responsibility

CSR is a commitment to contribute to sustainable economic development, working with employees, their families...