The American Iron and Steel Institute (AISI), in cooperation with CSA Group, today announced publication of the 2016 edition of the North American Specification for the Design of Cold-Formed Steel Structural Members (also referred to as the North American Specification, or Specification). The 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 2016 edition of the Specification has been reorganized―it includes the Direct Strength Method in the main body of the document in parallel to the traditional Effective Width Method; has a similar format to the AISC 360 specification for structural steel buildings; and minimizes the differences in design provisions between the U.S., Canada and Mexico. The reorganized Specification contains a main document—Chapters A through M and Appendices 1 and 2—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 also 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:

• Referenced standards―including those country-specific to the U.S. and Mexico, or Canada― are listed in the main body of the Specification.
• The previous country-specific design provisions for applications of other steels have been consolidated.
• The limitations for applying the Effective Width Method and the Direct Strength Method are streamlined.
• The system stability analysis, including second-order analysis, has been revised to be consistent with the method in AISC 360.
• The Direct Strength Method design provisions are incorporated into compression member design (Chapter E), flexural member design (Chapter F) and shear design (Chapter G).
• The interaction check equations for ASD, LRFD and LSD methods are combined into one format.
• AISI S240, North American Standard for Cold-Formed Steel Framing and AISI S400, North American Standard for Seismic Design of Cold-Formed Steel Structural Systems, are referenced for cold-formed steel light-frame construction applications. AISI S310, North American Standard for the Design of Profiled Steel Diaphragm Panels, is referenced for diaphragm design applications.   
• New provisions for power-actuated fastener embedment in concrete are added specifically for track connections in cold-formed steel framing applications.
• A total of 16 AISI test standards (AISI S900 series) are referenced.
• Statistical data for the determination of resistance factors are reorganized and greatly simplified in format.
• A new section, “Elastic Buckling Analysis of Members,” is introduced as Appendix 2.  

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 S100-16 in the United States and is available online for free download at www.aisistandards.org. In Canada, this edition is designated as CSA S136-16 and is available online for free download on CSA Group’s online store at www.shop.csa.ca. The North American Specification has been approved in the U.S. by the American National Standards Institute (ANSI) as the American National Standard, approved in Canada by CSA Group, and endorsed in Mexico by Camara Nacional de la Industria del Hierro y del Acero (CANACERO).