Seymour Tubing Inc. (STI) will spend $20 million to expand its automotive tubing plant in Seymour, Ind., according to state authorities.

STI, a joint venture between Sumitomo Metal Pipe & Tube Co. Ltd. and Mitsui & Co. (USA) Inc., will build a 51,000-square-foot addition and install tube forming and cutting equipment, as well as hire up to 18 additional workers.

"In conjunction with the expansion of our facility and the installation of tube forming and cutting equipment, STI will increase the number of employees at our facility," a spokesman said in a statement. A $90,000 state work force training grant will help STI "better serve our customers, our employees, our shareholders and our community."

STI, which employes more than 390 people currently, will begin hiring manufacturing, production and quality control personnel later this year, with the new production capacity scheduled to start up by July 2013.

The Seymour City Council approved a property tax abatement for the expansion.

"Indiana continues to see international companies invest in our automotive manufacturing industries," Indiana commerce secretary Dan Hasler said in a statement.

STI supplies carbon and stainless steel tubing used primarily in automobiles. The company has forecast that its 2012 sales will rise 20% compared with sales in each of the past three years, and expects to see an improvement of another 20% through 2015.

STI's expansion comes on the heels of Indiana Marujun LLC's announcement last week that it will invest nearly $21.8 million to increase capacity at its Winchester, Ind., facility, adding up to 50 new jobs, by 2015. Marujun, a Tier I automotive supplier, makes body parts and service parts for Honda Motor Co. Inc.