The objective of this Standard is to provide designers of cold-formed steel structures with specifications for cold-formed steel structural members used for load-carrying purposes in buildings and other structures.

This edition incorporates the following major changes to the previous edition:

(a) Inclusion of G500 and G550 steels in Clause 1.5.1.3 for steels where the effects of welding do not need to be tested.
(b) Inclusion of reference to first order elastic, second order elastic and advanced analyses in Clause 1.6.2.
(c) Earthquake design for Australia in Clause 1.6.4.1 based on structural ductility index and structural performance factor to align with latest edition of AS 1170.4.
(d) Earthquake design for New Zealand in Clause 1.6.4.2 allows structural ductility factors up to 6.
(e) Non-circular holes added to uniformly compressed stiffened elements in Clause 2.2.2.
(f) New Clause 2.2.5 on intermittent connections in uniformly compressed elements.
(g) Elastic buckling moments in Clause 3.3 moved to Paragraph D2.1, Appendix D, for members subject to bending.
(h) Elastic buckling stresses in Clause 3.4 moved to Paragraph D1.1, Appendix D, for concentrically loaded compression members.
(i) New Clause 3.7 for sections subject to combined bending and torsional loading.
(j) New Clause 4.1.2 for compression members composed of two sections in contact.
(k) Old Clause 4.3.3.3 for bracing of cleatless roof systems under gravity load deleted.
(l) Revised Clause 4.3.3.3 (old Clause 4.3.3.4) for neither flange connected to sheeting has improved equations and a new diagram.
(m) New equation for net section tension in Clause 5.3.3 has improved shear lag factor.
(n) Bolted connections in bearing in Clause 5.3.4 now includes oversize and short-slotted holes.
(o) Screws in shear and tension now allow the limit state based on testing of the screws.
(p) Screwed connections in tension in Clause 5.4.3.2 now include round head, hex head, pancake screw washer head, hex washer head and domed head.
(q) New rules in Clause 5.4.3.2 for screwed connections attaching roof battens.
(r) New rules for screwed connections in combined bending and tension.
(s) Design of power-actuated fasteners (PAFs) now included in Clause 5.5.
(t) Revised equations for block shear rupture in Clause 5.7.3 based on active shear planes.
(u) Range of prequalified members in Clause 7.1.1 (Table 7.1) for the direct strength method (DSM) extended to a wider range of sections with multiple intermediate stiffeners and return lips.
(v) Compression and flexural members with holes and flexural members with inelastic reserve capacity now included in the DSM Clauses 7.2.1 and 7.2.2.
(w) Shear and combined bending and shear added to the DSM in Clause 7.2.3.
(x) Combined compression/tension and bending added to the DSM in Clause 7.2.4.5 respectively.
(y) Design values based on prototype testing in Clause 8.4.1 can now use the average test value.
(z) Strength prediction model from testing based on verification model BV1 of National Construction Code (NCC).
(aa) New Section 9, Fire design, added for steel sections made from AS 1397, steel and with a fire resistant barrier.
(bb) New Appendix B, Paragraph B2, First order elastic analysis, Paragraph B3, Second order elastic analysis and Paragraph B4, Advanced analysis, added.
(cc) Appendix D extended to buckling stresses and actions for sections in compression, bending and shear including sections with holes.
(dd) Informative Appendix G added for members subject to non-uniform temperature distribution.

Notes to the text contain information and guidance. They are not an integral part of the Standard.

Sections of this Standard have been reproduced from AISIS100, North American Specification for the Design of Cold-Formed Steel Structural Members, with permission from the American Iron and Steel Institute.

Standards Australia thanks NASH (National Association of Steel-framed Housing) for permission to reproduce sections of NASH Standard—Residential and Low-rise Steel Framing, Part 1: Design Criteria in Clause 1.6 and Clause 8.4 of this Standard.

A statement expressed in mandatory terms in a note to a table is deemed to be a requirement of this Standard.

The terms ‘normative’ and ‘informative’ have been used in this Standard to define the application of the appendix to which they apply. A ‘normative’ appendix is an integral part of a Standard, whereas an ‘informative’ appendix is only for information and guidance.

Originated in Australia as AS 1538-1974. AS 1538-1988 jointly revised and redesignated AS/NZS 4600:1996. Previous edition 2005. Third edition 2018.