Quanex Corp. Houston, Tex., a manufacturer of engineered materials and components, has closed its asset purchase of the Monroe, Mich. steel mill of North Star Steel, a subsidiary of Cargill, Inc., for $115 million in cash. The company financed the acquisition by borrowing against its $310 million revolving credit facility. The mini-mill facility can produce over 500,000 tons of special bar quality and engineered steel bars in diameters from 0.5625 to 3.25 in., primarily serving the light vehicle and heavy-duty truck markets. The newly acquired business, with approximately $175 million annualized sales and 380 employees, will be integrated with Macsteel and renamed Macsteel Monroe.The facility has both process and environmental ISO and QS certifications.