The ASTM A242 specification is the standard specification for high-strength low- alloy structural steel for structural members where weight savings and atmospheric corrosion resistance are important. Mechanical property requirements are specified by product type (plates and bars, and structural Shapes) and by thickness.

ASTM A242 steel has atmospheric corrosion resistance

The steel plate under ASTM A242 standard also called the weathering steel plate, referred to the semi-killed or fully killed steel. It has good atmospheric corrosion resistance so the steel could be used in a lot of working environments.