Horizontal Position — What It Is and Why It Matters
Horizontal position (2G for groove welds, 2F for fillet welds) is welding on a vertical surface where the weld axis runs horizontally. The weld pool tends to sag downward due to gravity, requiring the welder to angle the torch or electrode slightly upward and manage heat to prevent the bead from rolling over on the bottom toe.
Horizontal welding is very common in structural fabrication — many beam-to-column connections, stiffener plates, and web splices are made in the horizontal position. It is less challenging than vertical or overhead but requires more skill than flat position, particularly for achieving consistent fillet weld leg lengths (gravity pulls the pool toward the bottom leg, making it larger than the vertical leg).
A 2G qualification test is often specified alongside or instead of a 3G test, depending on the code and application. Passing 3G qualifies the welder for 1G, 2G, and 3G positions, making it the more versatile single qualification.
Frequently Asked Questions
Why are my horizontal fillet welds uneven?
Gravity pulls the weld pool toward the lower plate, making the bottom leg larger and the top leg smaller. To compensate, aim the arc slightly higher (toward the upper plate) and use a work angle of about 45° but biased 5-10° toward the top. Practice is the best teacher — uneven legs are the most common horizontal fillet issue.
What does 2G mean?
2G designates a groove weld made in the horizontal position — the weld axis is horizontal on a vertical surface. 2F means a fillet weld in the horizontal position. These are intermediate-difficulty positions between flat (1G/1F) and vertical/overhead (3G/4G).