In the welding world, the is often called the "Holy Grail" of certifications. It is widely considered the most difficult and comprehensive test of a welder's skill because it requires performing a perfect weld around a pipe fixed at a permanent 45-degree angle .
You must manage the "sag" of the puddle as you move up the sides.
The 6G position is considered one of the most challenging pipe welding positions, as it requires the welder to work on the top side of the pipe, dealing with gravity and molten metal flow.