Mike, I understand that the tensile str of the weld material is a limiting factor in the overall strength of the joint... but I don't understand when you say that the penetration (or more importantly, the lack of penetration) is not a consideration. If there were no penetration, or perhaps extremely...

I've heard that vertical down mig welding makes for pretty weak joints, with poor penetration, so I thought I'd give it a test: I welded two 1/2" HRS plates together in a T joint, both sides vertical down. Then I laid the joint flat and clamped it to the table and started wailing with a two han...