A572

A572 refers to a family of high-strength, low-alloy structural steels specified by ASTM A572/A572M. These steels are intended for welded construction of structural members such as beams, channels, plates, and girders used in building frames and bridges. A572 steels combine higher yield strength with good weldability and formability, while maintaining compatibility with standard fabrication practices.

The standard defines several grades, including Grade 42, Grade 50, Grade 55, Grade 60 and Grade 65. Each grade designates a minimum yield strength in ksi (42, 50, 55, 60, and 65 respectively). Tensile strength and ductility increase with grade, and the exact properties depend on product form and thickness. The steels are low-carbon and are alloyed to achieve the specified strengths, with controlled levels of other elements to support weldability and toughness.

Welding and fabrication: A572 steels are prized for weldability and are commonly used in welded structures without requiring specialized heat treatments. They can be produced in plates, hot-rolled shapes, and bars, in a variety of thicknesses to meet design specifications.

Applications: Typical uses include structural frames for buildings, bridges, and other load-bearing steel structures, where high strength-to-weight and economical fabrication are important.

Standards: A572/A572M is the governing standard, with product forms and mechanical properties specified for each grade.

See also: high-strength low-alloy steel, HSLA steel, ASTM A572.