Specifies requirements for the welding of a wide range of welded construction using high strength quenched and tempered steels with a specified minimum yield strength not exceeding 800 MPa. It applies to statically loaded structures as well as some welds subject to fatigue conditions, and provides three categories of weld with three differing levels of weld quality assurance associated with the different types of service to which the welds are subjected. It aligns with AS 1554.1, Structural steel welding, Part 1: Welding of steel structures.