- Flat welds are the easiest welds to make. Note that the face in the flat position points straight up, even if the pieces themselves must be tipped at a 45 degree angle.
- Horizontal welds have gravity as a factor, but the welder's back is usually straight and tend to stay out of the breathing zone.
- Vertical welds are greatly dependent on the direction traveled. Downhill welding is easier because the weld pool follows the pull of gravity. Downhill welds tend to have shallower penetration than uphill welds. This is good or bad, depending on the depth of penetration required. Too much penetration on thin metals produces burn through. Vertical welds are also more sensitive to heat than flat and horizontal positions - too much heat and the liquid metal can spill out of the puddle and run down the face of the joint. Optimum heat for vertical welds is usually slightly less than for welds in other positions.
- Overhead welds are only possible because liquid metal has a fair amount of surface tension and will stay in the molten puddle as long as the puddle is not allowed to become too big. Because overhead welds require about the same heat input as flat welds, before welding overhead, it may be beneficial to practice a similar weld in the flat position.
Joint types: butt, corner, lap, tee, edge
Positions: flat, horizontal, vertical, overhead
Weld types: groove, fillet, plug, slot
Preparations: square, bevel, J, U
