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.

Driven By Excellence

Our reputation for providing high quality, low cost products, with on-time deliveries has led to our rapid growth as an automotive supplier. At the very foundation of our efforts at Kosei is the philosophy of “continuous improvement.”


Made of light aluminum alloy, Kosei wheels are designed for optimal cosmetic and structural integrity with the least amount of weight.  Defect prevention not detection is our focus during the manufacturing process. Training of our associates and managers, in our non-union plant, strives to enhance safety, quality, and process. To meet the needs of our customers and the challenges of our competitors requires the never-ending pursuit of excellence. 


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






"Supplying America's Automotive Industry"


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...

Industry Links

Honda ››

  • Accord
  • Accord Crosstour
  • Acura
  • Civic
  • CRV
  • Element
  • Pilot
  • Ridgeline

Subaru ››

  • Outback

Volkswagon ››

  • Jetta
  • Passat

Nissan ››

  • Infiniti
  • Rogue