flat width of cold formed steel sections

huangyhg

flat width of cold formed steel sections
for cold formed steel in gauge thickness, if you don't know what the corner radius is, can you take the flat width as the overall width minus three times the member thickness?  this is from the aisc spec for hollow structural sections. yes, i know that aisc governs for structural steel, and that aisi governs for light gauge steel.  i have not been able to find in the aisi spec a procedure to determine flat width thickness.
specifically, i have a 2" square 14 gauge steel tube, astm a500 steel that i am calculating the bending capacity for.  thanks.
look in page 5 of the pdf file for the ssma catalog, near the upper left for the inside corner radii used for design.
all the standard shapes in the aisi manual for 14 gage material have an inside radius of 3/32".  the flat width would be b-2*(t+r)=1.6625".  i would then specify a 3/32" radius.
thanks for your help.