BS 5950-5:1998 gives recommendations for the design of structural steelwork in buildings and allied structures using cold formed sections. It is primarily intended for steel sections of thickness up to 8 mm. Requirements for materials and construction are given in BS 5950-7.
Sections may be either open or closed and should be made up of flat elements bounded either by free edges or by bends with included angles not exceeding 1358 and internal radii not exceeding 5t where t is the material thickness.
Closed sections may be made either:
i) by joining together two previously formed open sections by continuous welding;
ii) from a single flat strip, by forming the corners to make a box, and continuously welding the longitudinal joint.
Welded cold formed hollow sections conforming to BS EN 10219 are not covered by this part of BS 5950.
NOTE Cold formed products conforming to BS EN 10219 are the subject of amendments to BS 5950-1 and -2 which are in preparation.