The 2024 edition of the North American Standard for Cold-Formed Steel Structural Members – AISI S100 has been completed and is available at: https://sdi.org/publications/publications/aisi-standards/ansi-sdi-aisi-s100-24/. All CFS researchers and engineers are encouraged to use the latest edition – and this 2024 edition is expected to be in effect until at least 2033 in the United States. ANSI/SDI AISI S100-24 includes simplifications for the Direct Strength Method including a new form for the base strength expressions and simplifications for direct design of beam columns. The provisions also include improvements for built-up member design, bracing design, fire performance-based design provisions (for the first time in the U.S. standard), and more. Creation of the standard included a large body of volunteers and was stewarded by Technical Director Dr. Tom Sputo at the Steel Deck Institute.
In 2023 the American Iron and Steel Institute (AISI) exited the creation of construction standards in the U.S.. See my open letter for the longer story. The Steel Deck Institute stepped up and provided an ANSI approved standards organization for completing the most recent code cycle – many of the updated AISI standards are available through SDI: AISI standards maintained by SDI. It is expected that SDI will continue to maintain standards relevant to steel deck, and they have led the effort to insure longevity of the standards to pertinent organizations. Former AISI Standards that pertain to cold-formed steel framing (AISI S202, AISI S220, AISI S230, AISI S240, AISI S250, AISI S400, AISI S910. AISI S911, AISI S913, AISI S914, AISI S915, AISI S916, AISI S917, AISI S918, AISI S919, AISI S920, and AISI S921) were transferred to the Steel Framing Industry Association (SFIA) in 2024. Former AISI Standards that pertain to metal building systems (AISI S901, AISI S906, AISI S908, and AISI S912) were transferred to the Metal Building Manufacturers Association (MBMA) in 2025.
The current expectation is that the American Institute of Steel Construction (AISC) will take over further development of AISI S100. This effort is currently in planning stages with a vision of providing a combined single U.S. standard for member and connection design of hot-rolled and cold-formed steel by 2033. Significant work remains for that vision to come to fruition, but working groups within AISC are already beginning this process.
It remains a dynamic time in the development of cold-formed steel structural standards in the U.S., but SDI’s release of ANSI/SDI AISI S100-24 is an important moment in the long-term development of cold-formed steel standards.