CFS Version 15 Changes Released October 2025

CFS now supports the 2024 Edition of the North American Specification for the Design of Cold-Formed Steel Members (S100-24). This includes ASD and LRFD for U.S. and Mexico, as well as LSD for Canada. CFS continues to support the 2022, 2020, 2018, 2016, 2012, 2010, 2007, 2004, and 2001 Editions. The CFS changes to support the 2024 Edition include:

• New DSM formulas for local and distortional buckling of beams and columns
• Determination of coefficients αs and βs for DSM beam strength
• New provisions for DSM lateral-torsional buckling strength
• New provisions for shear strength
• New provisions for torsion bimoment strength
• New provisions for torsion and bending interaction

• Added several steel grades for ASTM A1079 and A1088
• New DSM entries for gross and net section local buckling
• New DSM entries for αs coefficients
• New DSM entries for bimoment buckling
• Elastic buckling analysis for bimoment stress distribution
• Updated SFIA and SSMA libraries to include the new DSM entries
• Include X-Y axis orientation in printouts
• For messages about exceeded limits, the value and limit are both stated
• For global buckling of members with holes, show reduced properties in the calculation trace
• Allow closer hole spacing, down to 1 inch

• Allow adjacent elements in the same direction for all calculations except effective width, shear, and web-crippling
• Implemented increased Fcre for members with holes to calculate Fn for EWM local buckling
• Mne is limited to My for DSM local buckling strength (2022 and 2024 editions)
• In LRFD and LSD reports, use Pa, Ma, Va, etc. (available strengths) rather than ϕPn, ϕMn, ϕVn, etc.
• Fixed plastic section modulus for flat plate in minor axis bending
• Changed metric torque and bimoment units to use meters (m) rather than millimeters (mm)