I've attached two options for welding square HSS members of the same size together. I'm wondering which, if either, of the two options I show is most common. If neither, what's another option? In both options, you weld the first tube to the one I show in cross section using a flare-bevel weld. Now when you attach the third one you can no longer use a flare-bevel on the inside corner because you've welded shut your bevel. With option A you would do a bevel weld at the inside corner. This seems the most robust design but more difficult for the shop. With option B, the tube would simply be square cut and you would make a fillet weld on the inside corner. This is easier but it makes for strange goings on in the world stress right there.