A588 Steel is a High Strength Low Alloy Structural Steel, used in the construction of bridges and buildings. This steel possesses additional elements that produce high yield and tensile strengths as well as offering a high corrosion resistance to all types of weather conditions. The official standard, ASTM A588 was established by the organization ASTM International extends the same strength as A572 but with enhanced corrosion resistance when weathering the elements. An equivalent grade is Corten Steel, with a registered trademark name of United States Steel Corporation. The specification A588 applies to all foreign and Domestic Steel Plate as well as Structural shapes including Angles, Channels, Flat Bars, and Beams, that are fabricated, welded, riveted or bolted for use in mostly Bridge construction. Also employed in other similar applications A588 Steel is regularly used in the fabrication of structural steel buildings, railcar equipment and is well suited for use in shipbuilding. Outdoor structures and those that are regularly exposed to the elements are well suited to incorporating, as A588 Steel remains one of the best alternatives for finished structures.
This grade of steel is also known as and frequently referred to as "Weathering Steel" and can withstand the exposure to most weather conditions and elements. A588 Steel resists corrosion substantially better than standard Carbon Steel grades due to its chemical composition. A588 Steel was developed initially to eliminate the need for continuously having to be painted. This weather resistant steel can be left bare or uncoated as exposing it to atmospheric weather conditions allows for a protective rust-like layer to form, thereby shielding the steel from the weather and elements. As time passes by, the metal oxidizes and rusts, creating more of a protective barrier furthering slowing any corrosion.
The standard specification for this material requires a specific chemical composition and mechanical properties of performance. The main elements used in the chemical composition are Carbon, Manganese, Phosphorus, Sulfur, Silicon, Copper, Nickel, Chromium, Niobium, Molybdenum and Vanadium. The mechanical properties require a minimum 50,000, psi yield strength as well as a minimum tensile strength of 70,000 psi.