Specifies requirements for the welding of steel structures made up of combinations of steel plate, sheet or sections, including hollow sections and built-up sections, or castings and forgings, by the MMAW, SAW, GMAW, GTAW or TIG, FCAW, ESW and EGW processes. The Standard is limited to the welding of steel parent material with a specified minimum yield strength not exceeding 500 Mpa.