One of the most requested qualification tests in structural steel. The 3G covers flat, horizontal, and vertical positions — making it the practical choice for most fabrication and construction work.
The 3G is a Complete Joint Penetration (CJP) groove weld test performed in the vertical position — plate standing upright, welding progressing from bottom to top (uphill). The "3" means vertical, the "G" means groove weld. Downhill is not permitted for D1.1 structural qualification.
The test plate uses a 45° included angle CJP groove with a ¼" steel backing strip. For full thickness qualification you use 1" plate. For limited range you can use 3/8" plate. The difference matters — see the thickness table below.
This is the part that trips people up. Your 3G groove weld test also qualifies you for fillet welds in multiple positions — you don't need a separate fillet test. Here's exactly what you get per D1.1 Table 6.10:
| Weld Type | Positions Qualified |
|---|---|
| Groove Welds (CJP & PJP) | Flat (1G), Horizontal (2G), Vertical (3G) |
| Fillet Welds | Flat (1F), Horizontal (2F), Vertical (3F) |
| Overhead (4G/4F) | NOT covered — requires 4G test |
The plate you test on determines what you can weld in production. Per D1.1 Table 6.11:
| Test Plate Thickness | Qualified Thickness Range |
|---|---|
| 3/8" (9.5mm) | 1/8" minimum to 3/4" maximum |
| 1" (25mm) | 1/8" minimum to unlimited |
If your welders are going to be working on material over 3/4", test on the 1" plate. Don't make them retest because you saved $30 on plate material.
The process you qualify on is the process you're qualified to use in production. All of these work for 3G testing:
The workhorse. E7018 is the go-to for 3G — low hydrogen, good puddle control. E6010 for root passes. Uphill stick is a skill test, which is exactly the point.
Both FCAW-G (gas-shielded) and FCAW-S (self-shielded) work well for 3G. High deposition rates. Manage your slag or it'll manage you.
Short-circuit transfer for vertical. Tight parameter control — voltage and wire speed both matter. Note: GMAW-S requires bend tests only, no RT substitution.
Slower, more precise. Used where weld quality requirements are especially tight. Full capability in vertical uphill.
Once your plate arrives, we run the following per D1.1 Clause 6:
Step 1 — Visual Inspection: CWI examines the weld for cracks, undercut (max 1/32"), reinforcement height (max 1/8"), and crater fill. Any crack = automatic failure, no exceptions.
Step 2 — Weld Soundness: Either bend tests or radiographic testing (RT), depending on your process. For a 3G CJP plate, we cut specimens and bend them. Acceptance criteria: no single discontinuity over 1/8", no combined discontinuities over 3/8" total.
Step 3 — WPQ Records: CWI signs the Welder Performance Qualification record. You get the signed WPQ plus lab reports. That's your official documentation. File it. Start your continuity log.
Fail the 3G? You can retest, but the code governs how. Per D1.1 Clause 6.25, if the failure is due to lack of skill (not a procedure issue), a retest is allowed after additional practice. You'll need to retest the failed position — not just resubmit the same plate. Call us and we'll walk through what happened.
| Position | Vertical (uphill) |
| Weld Type | CJP Groove |
| Backing | 1/4" steel strip |
| Groove Angle | 45° included |
| Test Thickness | 3/8" or 1" |
| Covers Overhead? | No |
| D1.1 Reference | Table 6.10, 6.11 |
The 3G+4G combo qualifies everything — all positions, unlimited thickness. One test.
3G/4G All-Position