|   difficult weld |   bad adjustment |   tack weld which must be continuous weld | 
|   big weld job, two welders needed |   welder must be left handed |   Very big and expensive weld | 
|   Bad quality very probable |   used in case if it is unknown from which side has to be welded |   Used for tack welds, when the connected parts will anyway not fit together | 
|   Special weld mark for welding engineers to demonstrate high knowledge of welding technology |