Welding position determines more than joint geometry — it defines the range of work a welder can legally perform and the scope a WPS can claim. Misread the position qualification ranges, and you can have a welder assigned to overhead joints with a WPQ that covers flat and horizontal only, or a WPS applied to vertical-up joints when the PQR was run flat.
AWS D1.1 defines positions systematically, assigns them difficulty tiers, and allows higher-tier tests to cover lower-tier work positions. Understanding that tier system is the difference between a qualification program that runs lean and one that generates retest after retest.
The Four Plate Positions
AWS D1.1 uses a numeric-plus-letter notation for position. For plate:
1G — Flat. The joint is oriented so welding is performed from above, with the weld axis horizontal. The easiest position mechanically. Gravity works with the welder — the weld pool stays put and the bead is easy to control. Travel speed, bead shape, and interpass cleaning are the primary variables to manage.
2G — Horizontal. The joint is vertical, the weld axis horizontal. Gravity wants to pull the bead downward, creating the risk of undercut on the top toe and overlap on the bottom. Most processes can handle 2G without significant technique adjustment; GMAW short-circuit and spray transfer both run well in 2G on structural steel.
3G — Vertical. The joint is vertical, the weld axis vertical. Welding progresses either uphill (3G-up) or downhill (3G-down). Uphill is the standard for most structural groove weld applications — it produces better fusion at the root and sidewalls than downhill travel. Downhill is typically limited to thin-section fillet welds and certain GMAW short-circuit applications. A welder qualified 3G-up is not automatically qualified 3G-down.
4G — Overhead. The joint is horizontal, welding performed from below. The hardest plate position: gravity opposes the welder, weld pool control requires constant attention, and spatter management becomes critical for maintaining consistent bead geometry.
Rule library based on AWS D1.1:2025; verify against your governing edition.
Plate Position Qualification Ranges
The test position establishes the range of production positions the WPS or WPQ covers:
| Test Position | Groove Positions Qualified |
|---|---|
| 1G | 1G only |
| 2G | 1G, 2G |
| 3G | 1G, 2G, 3G |
| 4G | 1G, 4G |
| 3G + 4G | All plate positions |
The most common all-position qualification path in structural fab shops is the 3G+4G combination. Run both tests, pass both, and the welder is cleared for any plate joint orientation. Many shops qualify all new structural welders on 3G+4G to avoid scope issues mid-project.
Notice that 4G alone covers only flat and overhead — it does not cover horizontal or vertical. A welder who tested in overhead only and is then assigned to vertical-up groove joints is outside their qualified range, even though overhead is mechanically more demanding.
Pipe and Tube Positions
Pipe positions use a different notation to reflect the fixed (non-rotating) nature of the test coupon in most real-world applications:
1G (pipe rotated) — Flat. The pipe rotates under the torch; welding is always performed in the flat position at the top of the joint. Qualifies for flat position only. This test is rarely used for qualification purposes because it doesn't reflect field conditions.
2G (pipe horizontal fixed) — Horizontal. The pipe axis is vertical, the pipe is fixed, and the welder travels around the joint in the horizontal position throughout. Qualifies for 1G and 2G.
5G (pipe vertical fixed) — Multiple. The pipe axis is horizontal, the pipe is fixed. The welder encounters flat, vertical, and overhead positions as they travel around the joint. A 5G test qualifies for 1G, 2G, 3G, and 4G positions.
6G (pipe inclined fixed) — All positions. The pipe is fixed at a 45° incline. This is the most challenging pipe qualification test because the welder encounters an asymmetric rotation through all positions simultaneously. Passing 6G qualifies for all pipe welding positions.
| Test Position | Pipe Positions Qualified |
|---|---|
| 1G (rotated) | 1G only |
| 2G (horizontal fixed) | 1G, 2G |
| 5G (vertical fixed) | 1G, 2G, 3G, 4G |
| 6G (inclined fixed) | All positions |