Whether for home, farm, builder or industrial customers, National has all the right hardware in the sizes and finishes you need. With over a century of service National is committed to maintaining the highest level of product quality, innovation and manufacturing technology. Quality metal sheets and rod both threaded and smooth for all for your construction projects. Plain steel contract-it materials allow you to weld, form and fabricate easily because the steel is not treated with oil. The plain steel assortment includes angles, flats, sheets, sheet metal, channels, tubes and rods, rebar and squares, among others.