WASHINGTON, D.C. – The American Iron and Steel Institute (AISI), in cooperation with CSA Group, announced publication of the new edition of the North American Specification for the Design of Cold-Formed Steel Structural Members. This latest edition provides updated information from recent advances in research on cold-formed steel design. It supersedes all previous editions.

The North American Specification harmonizes cold-formed steel design technology across the United States, Canada and Mexico, allowing for faster introduction of new technologies as well as opening up the market for a variety of derivative products such as design aids and educational materials. The Specification includes a main document—Chapters A through G and Appendices 1 and 2—that is intended for use by all three countries. There are two country-specific appendices: Appendix A is for use in the United States and Mexico, and Appendix B is for use in Canada. The Specification provides an integrated treatment of Allowable Strength Design (ASD), Load and Resistance Factor Design (LRFD), and Limit States Design (LSD).

Reflecting ongoing research to develop new and improved information on the structural behavior of cold-formed steel members, the new edition includes the following additions and revisions:

  • Addition of material standard ASTM A1063.
  • Reorganization of all referenced ASTM material standards in accordance with the ranges of the minimum specified elongation.
  • Addition of Section B1.3, Corner Radius-to-Thickness Ratios.
  • Addition of Section B2.5, Uniformly Compressed Elements Restrained by Intermittent Connections.
  • Unification of country-specific provisions on tension member design, which have been moved to the main body of the Specification.
  • Revision of the reduction factor for combined bending and torsional loading.
  • New provisions on combined shear and tension on arc spot welds and top arc seam sidelap welds.
  • Provisions for determining the web shear strength using the Direct Strength Method, which is an alternative approach for determining the strength and stiffness of cold-formed steel beams and members.
  • New design provisions for power-actuated fasteners, which are widely used in building construction.

The North American Specification is the result of a cooperative effort by AISI’s Committee on Specifications for the Design of Cold-Formed Steel Structural Members and the CSA Group Technical Committee on Cold Formed Steel Structural Members.

The new edition is designated as AISI S100-12 in the United States and is available for purchase on AISI’s website at www.steel.org. In Canada, this edition is designated as CSA S136-12 and is available for purchase on the CSA Group’s online store at www.shop.csa.ca. It has been approved in the U.S. by the American National Standards Institute (ANSI) as the American National Standard, developed in Canada by CSA Group, and endorsed in Mexico by Camara Nacional de la Industria del Hierro y del Acero (CANACERO).