AK Steel said today that it will increase transaction base prices by 10% to 16% for stainless steel alloys used primarily in automotive exhaust applications, effective with shipments on July 1, 2007. The transaction price will increase by 10%, or US$120 per ton, for Type 409, and by 10%, or US$180 per ton, for Type 439. Transaction prices will also increase by 10% for Type 409 Ni, Aluminized 409 and Aluminized 439. Due to recent increases in the cost of columbium (also known as niobium), transaction base prices for 18 Cr-Cb(TM), 15 Cr-Cb(TM) and 410 Cb will increase by approximately 16%. The company said that all of its existing raw material surcharges will remain in effect. Headquartered in Middletown, Ohio, AK Steel produces flat-rolled carbon, stainless and electrical steel products, as well as carbon and stainless tubular steel products, for automotive, appliance, construction and manufacturing markets.