FPHSD — Cold-Formed Steel Member Connection Loads, Steel-to-Steel
Screws and connections have been tested per AISI Standard Method
S904-08 and S905-08.
The tabulated ASD and LRFD allowable loads for cold-formed steel (CFS)
members are based on the lower of the screw strength or the strength of the
screw in the connected members per AISI S100-07 Section E4.
Values are based on CFS members with a minimum yield strength of
Fy = 33 ksi and tensile strength of Fu> = 45 ksi for 43 mil (18 ga.) to 27 mil
(22 ga.), minimum yield strength of Fy = 50 ksi and Fu> = 65 ksi for 54 mil
(16 ga.) to 97 mil (12 ga.).
For design purposes, steel sheet thicknesses are 0.0283" for 27 mil, 0.0346"
for 33 mil, 0.0451" for 43 mil, 0.0566" for 54 mil, 0.0713" for 68 mil, and
0.1017" for 97 mil. The actual sheet thickness shall not be less than 95% of
these design thickness as specified in AISI S100-07 Section A2.4.
Screw diameters per AISI S200-07 General Provision Commentary Table D1.1.
Minimum required screw length is the lesser of 3/4" or the minimum length
required for the screw to extend through the steel connection a minimum of
three exposed threads per AISI S200-07 General Provisions Standard Section
Screw head dw for #10 and #12 screws is 0.357".
The allowable load (ASD) values shown are not permitted to be increased for
short-duration loads such as wind or earthquake loads.
The lower of the pull-over and pull-out allowable load should be used for
The tabulated shear values are based on the thinner steel member in
connection. Steel thickness for both members must be in the range of
FPHSD (#10) Screw — (Sheet Steel Sheathing-to-CFS)
Nominal Shear Strength (Rn) for Wind (W) and Seismic (S) for Shear Walls1 (lb./ft.)
Nominal strength shall be multiplied by the resistance factor (Φ = 0.6, LRFD
Seismic, Φ = 0.65, LRFD Wind) to determine design strength or divided by
the safety factor (Ω = 2.5, ASD Seismic, Ω = 2.0, ASD Wind) to determine
Screws in the field of the panel shall be installed 12" (305 mm) on center (o.c.).
Shear wall height-to-width aspect ratio (h/w) greater than 2:1, but not exceeding
4:1, shall be permitted provided the nominal strength values are multiplied by 2w/h.
Wall studs and track shall be of ASTM A1003 Structural Grade 33 (Grade 230)
Type H steel for members with a designation thickness of 33 and 43 mil.
In lieu of blocking, panel edges shall be permitted to be overlapped and attached
to each other with screw spacing as required for panel edges. Where such a
connection is used, tabulated design values shall be reduced 30%.
Maximum stud spacing 24" o.c.
Blocking, if applicable, shall be a minimum 33 mil 1 1/2" width.
Table based on Table C2.1-1 AISI Standard North American
Standard for Cold-Form Steel Framing-Lateral Design 2007 Edition with
Supplement No. 1 and Commentary.