Specifies the technical requirements for cold-formed steel hollow sections for structural purposes, for the six grades of steel that are suitable for welding. Grade C200 and all hot-formed grades have been deleted. It includes a new cold-formed grade C450 and grades with guaranteed impact performance at 0¿¿C, namely C250L0 and C450L0. Tensile strengths of grades C250 and C350 are reduced to reflect the properties obtained on cold-formed sections.