AWS B2.1 is not a code, it is primarily a standard for qualifying welding procedures and welders.
AWS D1.6 is the structural welding code for stainless steel, but it is for materials 1/8 inch or thicker.
If I remember correctly, the structural sheet metal code is primarily for carbon steel. I have a copy around here somewhere, the the devil is trying to locate it.
Best regards - Al
Best regards - Al