So happens i was working on a fence bracket for a machine in the wood shop and was adding a 3/8" flat to a piece of 3/8" x 3" flat bar. 200DX was flawless heated up quick made short work of the weld. 160 amps 15cf gas 1/8" 4043 filler. Maybe Mark or someone can shed some light on the thickness rating. But as far as i am concerned for what i am doing it will be just fine on 3/8"
Attachment 8714.