Why doesn't the 4G alone cover the 3G vertical position?

Per AWS D1.1 Table 6.10, the qualification scope is based on what positions were actually tested. The 4G demonstrates skill in the overhead position, which by the code's logic also qualifies the easier flat and horizontal positions. Vertical is a separate skill set and requires its own test. This is why most contractors request the combined 3G/4G test rather than either position alone.

What plate thickness do I need for unlimited thickness qualification?

Use a 1-inch (25mm) ASTM A36 test plate. Per D1.1 Table 6.11, a 1-inch plate qualifies the welder for unlimited production thickness. A 3/8-inch plate only qualifies up to 3/4-inch production thickness.

What is the joint configuration for the 4G plate test?

The standard joint per AWS D1.1 is a single V-groove CJP with 45-degree included angle (22.5 degrees per side), 1/4-inch root opening, knife-edge root face, and a 1/4-inch by 1-inch A36 backing bar. Base metal is ASTM A36. This is identical to the 3G joint configuration — the only difference is the plate orientation.

What welding processes can be used for the 4G test?

SMAW with E7018 electrodes is the most common and provides the best puddle control overhead. FCAW-G and FCAW-S are also permitted. GMAW short-circuit transfer is technically allowed but rarely used overhead due to spatter and heat management challenges. Each process qualifies separately.

How many bend tests are required for the 4G qualification?

Four guided bend tests are required: two face bends and two root bends. The backing bar is removed before specimens are cut. Each specimen is bent 180 degrees. No individual discontinuity may exceed 1/8 inch in any direction.

Is the 4G the hardest plate qualification test?

Yes — the 4G overhead is widely considered the most physically demanding single-position plate test. Welding with the plate above you means molten metal constantly wants to drip toward you. Managing arc length, heat input, and puddle control while in an awkward body position makes the 4G a genuine test of skill. Many experienced welders consider it more demanding than the 3G vertical.

Should I take the 4G alone or the 3G/4G combined test?

If you already hold a valid 3G qualification and only need to add overhead coverage, the standalone 4G test is the efficient choice. If you are starting fresh and want full all-position qualification, the combined 3G/4G test is more cost-effective than two separate tests and explicitly qualifies all positions in one session.

What is the most common failure on the 4G overhead test?

Puddle sag and overlap are the most common failures — the overhead puddle runs and flows over the base metal, creating a visual rejection for overlap before bend testing even occurs. The second most common failure is incomplete root fusion on the root bend specimens, caused by insufficient heat or incorrect arc angle on the root pass. Arc strikes outside the weld zone are also an automatic rejection.

Can I mail in my 4G test plate for inspection?

Yes. WeldCertTest provides a complete mail-in service for 4G qualification. Your welder completes the overhead plate under a qualified WPS at your shop, you ship it to us, and our AWS CWI performs visual inspection followed by accredited bend testing. Official WPQ documentation is issued on passing.

How long does the 4G certification remain valid?

Per AWS D1.1 Clause 4.25, the qualification is valid indefinitely as long as the welder uses the qualified process at least once every six months. The employer must maintain a continuity log with sign-offs at each six-month interval. If more than six months passes without using the process, the qualification expires.

What industries require the 4G overhead plate qualification?

Structural steel erection contractors, shipyards, bridge construction crews, heavy equipment manufacturers, and any operation governed by AWS D1.1 that involves overhead groove welds require the 4G qualification. Field erection work in particular involves significant overhead welding on beam connections and structural column joints.

AWS D1.1 4G Overhead Welder Qualification | Mail-In WPQ

Q: What positions does the AWS D1.1 4G qualification cover?

The 4G overhead plate qualification covers groove welds in flat (1G), horizontal (2G), and overhead (4G) positions per AWS D1.1 Table 6.10. It also qualifies fillet welds in 1F, 2F, and 4F positions. It does not cover the 3G vertical position — a separate 3G test is required for vertical, or the combined 3G/4G test covers all positions at once.

Q: What electrode size works best for 4G SMAW overhead?

3/32-inch E7018 electrodes provide better puddle control overhead compared to 1/8-inch. The smaller diameter allows slightly lower amperage while maintaining arc stability, making it easier to keep the puddle tight and prevent sag. Many welders use 3/32 for the root and first fill pass, then step up to 1/8 inch only if they feel confident controlling the larger puddle overhead.

What Is the 4G Plate Qualification?

The AWS D1.1 4G plate qualification is a Complete Joint Penetration (CJP) groove weld test performed in the overhead position — the plate is positioned horizontally above the welder, and the weld is made from below. It is the most physically demanding single-position plate test in structural welding.

The "4" designates overhead. The "G" designates groove weld. Every ounce of molten metal wants to fall toward the floor — or toward the welder. Controlling the puddle overhead requires short arc length, lower-than-flat amperage, deliberate travel speed, and consistent body position. Passing the 4G is a legitimate demonstration of advanced welding skill.

Professional welder in full leather PPE and welding helmet performing overhead groove weld with bright arc and sparks falling downward, plate positioned horizontally above in steel welding fixture — **4G overhead position in practice:** The plate is fixed horizontally above the welder. Sparks and spatter fall continuously. Short arc length and controlled travel are critical — the puddle will sag and overlap the base metal the moment heat gets away from you.

Why the 4G Is the Hardest Plate Test

Every other plate position has gravity working with you to some degree — even the 3G vertical uphill allows the puddle to build against the leading edge of the bead. Overhead removes that entirely. The puddle has no support except the surface tension of the molten metal and the freezing rate of the filler. The welder's only tools are arc length and travel speed.

Beyond the physics, the body position is uncomfortable. Welding overhead means working with arms raised, neck craned back, and spatter falling directly at your face and neck. Fatigue sets in faster than any other position. The best overhead welders aren't necessarily the most technically gifted — they're the ones who've conditioned their bodies for the position and can hold a consistent arc through discomfort.

Physical Preparation Matters: Before test day, practice your bracing position. Find where your elbows rest, how your arm sweeps along the joint, and where you stand relative to the plate. Overhead welding fatigue is real — running five practice plates is worth more than any amount of reading about technique.

What the 4G Qualification Covers

A standalone 4G qualification provides broad position coverage — but with one notable gap. Per AWS D1.1 Table 6.10, passing the 4G overhead groove weld test qualifies the welder for the following positions:

4G position coverage per AWS D1.1 Table 6.10
Weld Type	1G Flat	2G Horiz.	3G Vert.	4G OH	1F	2F	3F	4F
4G Groove Test	✓	✓	✗	✓	✓	✓	✗	✓

The gap is the 3G vertical position and 3F vertical fillet. The 4G does not cover vertical. This surprises many welders — intuitively, passing the hardest position should cover everything. But per D1.1's qualification logic, vertical is a distinct skill set that requires its own test. If your production work includes both overhead and vertical groove welds, you need either the standalone 3G in addition to this test, or the 3G/4G combined qualification which covers all positions at once.

⚠ Vertical (3G) Is NOT Covered: A standalone 4G qualification does not qualify the welder for vertical groove welds. If a job site requires "all-position certified," the 4G alone will not satisfy that requirement — you need the combined 3G/4G test.

Thickness Qualification

Same rule as every other plate test — the thickness you test on determines what you can weld in production. Use the 1-inch plate. The cost difference is minimal, the downside of testing on 3/8-inch and discovering the project requires unlimited thickness is not.

4G Thickness Qualification — AWS D1.1 Table 6.11
Test Plate	Min Production	Max Production	Recommended?
3/8" (9.5mm)	1/8"	3/4" max	Light fab only
1" (25mm)	1/8"	Unlimited	Yes — always

Test Plate Specifications

Plate Material

ASTM A36 Structural Steel

Plate Thickness

1 inch (unlimited qualification)

Groove Angle

45° included (22.5° per side)

Root Opening

1/4 inch

Root Face

Knife edge (0" land)

Backing Bar

1/4" × 1" × 8" A36

Joint Type

CJP Single V-Groove

Position

Plate horizontal overhead

Welding Processes for the 4G Test

Process selection matters more on the 4G than any other position. The overhead environment punishes processes that produce a fluid, slow-freezing puddle. SMAW E7018 dominates because it freezes quickly and the welder has direct control over heat through arc length and travel speed.

SMAW — E7018 (Recommended)

Best puddle control of any process overhead
Use 3/32" electrodes — smaller diameter = lower amperage = tighter puddle
E7018 freezes faster than E6010, better for fill and cap overhead
Store in rod oven — wet electrodes cause porosity and cracking
Work angle: 90° perpendicular to plate face (pointing straight up)
Travel angle: 5°–15° in direction of travel
Most universally accepted by all structural contractors

FCAW — Flux-Cored

FCAW-G (gas-shielded) works overhead with correct parameters
Higher deposition than SMAW — faster but harder to control
Reduce wire speed and voltage below flat position settings
FCAW-S (self-shielded) viable for outdoor overhead work
Slag removal overhead is harder — chip aggressively between passes
Requires more practice to master overhead than SMAW

GMAW — MIG (Short-Circuit)

Technically permitted under D1.1 for overhead
Short-circuit transfer only — spray arc overhead is not viable
High spatter overhead — full leather PPE essential
Per D1.1: RT cannot substitute for bend tests on GMAW-S
Less common for overhead structural testing — SMAW preferred
Check project specs — some restrict GMAW on structural plate

Process Comparison — 4G Overhead

SMAW: Best control, slowest, universal acceptance ✓
FCAW-G: Good if parameters dialed, higher deposition
FCAW-S: Field/outdoor overhead, no gas needed
GMAW: Rarely used overhead, check specs first
Each process qualifies separately — SMAW cert doesn't cover FCAW
Match your test process to your production process

4G Overhead Welding Technique

Every experienced overhead welder will tell you the same thing: it's 80% body position and 20% technique. If you're uncomfortable, shaking, or can't brace your arms, no amount of welding knowledge will save you. Get comfortable first, then focus on arc length and travel speed.

Body Position and Bracing

Brace both elbows against your torso or the fixture — eliminate shake
Position your head to the side of the joint, not directly below it
Crouch or kneel so the plate is 8–12 inches above your helmet — not arm's length
Full leather jacket, gloves, and rear neck protection — spatter burns are serious overhead
Use a welding blanket over your lap and shoulders if possible
Test your body position before striking the arc — can you travel the full joint without repositioning?

Root Pass Overhead

Keep arc length extremely tight — half the electrode diameter maximum
Move slightly faster than feels natural — puddle sag starts the moment you slow down
Use 3/32" electrodes for root — better control than 1/8"
A narrow, slightly convex root bead is correct — wider is not better overhead
Don't stop mid-pass if you can avoid it — a cold restart creates a slag trap
Chip and grind root pass before fill — overhead slag is harder to see

Fill Passes Overhead

Run stringer beads — no weaving overhead
Each pass should be narrow and slightly convex — flat or concave will sag
Grind any high spots flush before the next pass — humps trap slag
Chip and wire brush every pass more aggressively than you would flat
Allow brief interpass cooling — hot plate + overhead = guaranteed sag
Build the groove with 3–4 stringers rather than 1–2 wide passes

Cap Pass and Final Inspection

Cap reinforcement must stay under 3/16" — high caps fail visual
Keep travel speed consistent — speed changes create high/low profile
Tie tightly into both toes — undercut overhead is the most common visual failure
After welding, inspect base metal adjacent to the weld for arc strikes
Let the plate cool before shipping — thermal stress during transport won't affect welds but handling hot plate is dangerous

Close-up of leather-gloved hand holding E7018 stick electrode performing structural welding, showing bright arc, consistent weld bead, and heat affected zone on steel plate — **SMAW E7018 technique — electrode control:** The same tight arc length and deliberate travel speed used on vertical uphill applies overhead — but with even less margin for error. Overhead removes the puddle support that vertical provides. Every millimeter of arc length increase risks puddle sag.

Common 4G Test Failures — And How to Avoid Them

Puddle Sag and Overlap

The overhead puddle runs downward and flows over the base metal — automatic visual rejection for overlap. Cause: arc length too long, amperage too high, travel speed too slow. Fix: shorten the arc, reduce amperage 10–15% from flat position settings, increase travel speed slightly, and run narrow stringer beads rather than weaving.

Incomplete Root Fusion

Most common bend test failure. Root pass didn't fully tie in to the backing bar, shows as a planar defect on root bend specimens. Cause: arc too far from the root, inconsistent root gap, or moving too fast through tight sections. Fix: aim the arc directly at the root opening, verify consistent 1/4" gap before starting, slightly higher amperage on root than fill passes.

Undercut at Cap Toes

Undercut exceeding 1/32" is an automatic visual rejection. Cause: moving too fast at the toes while trying to avoid sag, or excessive amperage on the cap. Fix: run the cap as stringer beads tied tightly into each toe. Pause briefly at each toe edge to ensure full tie-in. Reduce cap amperage below fill pass settings.

Arc Strikes Outside Weld Zone

Per D1.1 Clause 4.9, any arc strike on the base metal adjacent to the weld is an automatic visual rejection — no exceptions. Overhead welding increases this risk because electrode angles shift during repositioning. Fix: strike the arc on a scrap piece and transfer to the joint. Inspect base metal carefully before shipping the plate.

Slag Inclusions from Poor Interpass Cleaning

Overhead slag is harder to see and easier to miss. A thin layer of residual slag welded over creates linear inclusions that fail the bend specimens. Fix: chip every pass thoroughly, use a wire wheel grinder on each pass, and hold the plate at an angle under a light source to spot any residual slag before the next pass.

Body Fatigue Causing Inconsistent Travel

Overhead welding is tiring. As arms fatigue, arc length creeps up and travel speed slows — both cause puddle sag and inconsistent bead profile. Fix: condition your body before test day with practice sessions. On test day, take the time to position comfortably before each pass. A 30-second pause to adjust your stance is worth more than rushing through with bad bracing.

Visual Inspection Requirements

The completed 4G plate must pass visual inspection by an AWS CWI before any bend specimens are cut. Overhead plates get the same inspection criteria as every other position — the code makes no allowance for the difficulty of the position.

Visual Acceptance Criteria — AWS D1.1 Clause 4.9
Discontinuity	Limit	Notes
Cracks	None permitted	Any crack = immediate rejection
Incomplete fusion	None permitted	Anywhere in joint
Undercut	≤ 1/32" (0.8mm)	Depth at toe of weld
Reinforcement height	≤ 3/16" (4.8mm)	Above base metal surface
Arc strikes	None outside weld zone	Automatic rejection — no exceptions
Overlap	None permitted	Most common overhead visual failure
Porosity	Per D1.1 Clause 4.9.3	Size and frequency limits apply

Guided Bend Testing

Plates passing visual proceed to accredited laboratory bend testing. Four specimens are cut: two face bends and two root bends. The backing bar is removed before cutting. Each specimen is bent 180° in a guided bend jig. All four must pass — one failure fails the entire test.

Specimens Per Plate

4 (2 face, 2 root)

Bend Angle

180 degrees

Max Discontinuity

1/8" in any direction

Backing Bar

Removed before bending

Welder Performance Qualification Record document on wooden desk showing fields for welder name, process, position, test date, and certified welding inspector signature line, with hard hat and welding gloves in background — **Welder Performance Qualification (WPQ) record:** The official CWI-signed document issued on passing. Your contractor, project inspector, and owner will ask for this document by name. WeldCertTest issues WPQ records on all passing 4G tests.

4G Standalone vs. 3G/4G Combined — Which Do You Need?

This is the most important decision before you order a test. The answer depends on what the welder already holds and what the project requires.

Situation	Best Choice	Why
Welder already holds valid 3G, needs overhead added	4G Standalone	Most efficient — adds overhead without retesting 3G
Starting fresh, want full all-position qualification	3G/4G Combined	One session, one cost, covers everything
Project requires "all-position certified"	3G/4G Combined	4G alone doesn't cover 3G vertical
Project only involves overhead groove welds	4G Standalone	No need to pay for 3G if not required
Ironworker field erection work	3G/4G Combined	Field work involves both vertical and overhead joints

4G vs. All Plate Qualifications

Test	Groove Positions	Vertical?	Overhead?	Plates
1G Flat	1G only	No	No	1
2G Horizontal	1G, 2G	No	No	1
3G Vertical	1G, 2G, 3G	Yes	No	1
4G Overhead	1G, 2G, 4G	No	Yes	1
3G/4G Combined	All — 1G, 2G, 3G, 4G	Yes	Yes	2

Certification Validity — The 6-Month Rule

Per AWS D1.1 Clause 4.25, the 4G qualification is valid indefinitely as long as the welder uses the qualified welding process at least once every six months. The employer maintains a continuity log. If more than six months passes without using the process, the qualification expires and retesting is required.

✓ Continuity Tip: Even a single overhead fillet weld using the qualified process counts toward continuity. Keep your log current and you will never need to retest purely due to a paperwork gap.

Mail-In Service — How It Works

Contact us for WPS and quote

Confirm the process (SMAW, FCAW, etc.) and we provide pricing plus a qualified WPS. If you have an existing D1.1 prequalified WPS, you may use it.
Weld the overhead plate at your shop

Your welder completes the 4G plate under the WPS at your facility. Plate horizontal overhead in a fixture, 45° groove, 1/4" root opening, backing bar in place.
Ship the completed plate

Follow our shipping instructions. Standard ground shipping is fine. Include welder name, contact info, and process with the shipment.
CWI visual inspection

Our AWS CWI performs full visual inspection per D1.1 Clause 4.9. We contact you on any visual rejection before proceeding to bend testing.
Accredited bend testing

Four specimens cut, prepared, and bent per D1.1 at our accredited testing lab. Full test data documented.
WPQ issued and delivered

CWI signs and issues the official Welder Performance Qualification record on passing. Delivered by email and mail. See timeframes for turnaround.

Industries That Require the 4G Qualification

Structural Steel Erection

Field ironworker crews performing beam-to-column connections and structural splices encounter overhead groove welds regularly. Most structural erection contractors require the 4G or 3G/4G combined qualification.

Shipyards and Marine

Ship hull construction involves welds in every orientation including significant overhead work. Shipyard structural welders routinely hold 4G qualifications as a baseline credential.

Bridge Construction

Bridge girder flange and web connections, diaphragm attachments, and under-deck connections involve overhead groove welds requiring 4G qualification on D1.1 and D1.5 projects.

Industrial Maintenance

Maintenance welding on existing structures, process equipment, and plant infrastructure regularly involves overhead joints where equipment layout prevents repositioning the work.

Glossary

4G Position

Overhead groove weld position per AWS D1.1. Plate is horizontal above the welder, weld made from below. The most physically demanding plate position.

CJP — Complete Joint Penetration

A groove weld with full fusion through the entire joint thickness. The 4G test uses a CJP single V-groove with permanent steel backing bar.

Puddle Sag

Molten weld metal that flows downward under gravity during overhead welding, causing overlap on the base metal. The most common overhead welding defect.

WPQ — Welder Performance Qualification

Official AWS document signed by a CWI certifying the welder's qualification. Lists process, positions covered, thickness range, and test results.

E7018 Electrode

Low-hydrogen SMAW electrode preferred for overhead structural welding. Freezes quickly, provides better puddle control overhead than higher-hydrogen electrodes.

Continuity (6-Month Rule)

D1.1 Clause 4.25 requirement: welder must use the qualified process at least once every 6 months or the qualification expires.

Frequently Asked Questions

What positions does the 4G qualification cover?

The 4G covers groove welds in flat (1G), horizontal (2G), and overhead (4G) positions per AWS D1.1 Table 6.10. It also qualifies fillet welds in 1F, 2F, and 4F positions. It does not cover the 3G vertical position or 3F vertical fillet — those require a separate 3G test or the combined 3G/4G qualification.

Why doesn't the 4G cover the 3G vertical position?

Per D1.1 Table 6.10, qualification scope is based on the positions actually tested. Overhead and vertical are treated as distinct skills under the code. Passing the hardest position does not automatically qualify the others — vertical requires its own test. This is the primary reason most contractors require the combined 3G/4G test rather than either position alone.

Should I take the 4G alone or the 3G/4G combined?

If you already hold a valid 3G qualification, the standalone 4G is the efficient choice — it adds overhead without retesting what you already hold. If you are starting fresh or your contractor requires all-position certification, go directly to the combined 3G/4G test. It covers everything in one session at a lower combined cost than two separate tests.

Is the 4G really the hardest plate test?

Yes — universally regarded as the most physically demanding single-position plate test. Gravity acts directly against the weld puddle, body position is uncomfortable, and fatigue sets in faster than any other position. Many welders who pass the 3G on their first attempt take multiple attempts on the 4G. The 6G pipe test is comparable in difficulty but involves a round pipe rather than flat plate.

What electrode size is best for 4G SMAW overhead?

3/32-inch E7018 provides better puddle control overhead than 1/8-inch. The smaller diameter allows lower amperage while maintaining arc stability, making it easier to keep the puddle tight and prevent sag. Most experienced overhead welders use 3/32 throughout or at minimum for the root and first fill pass before stepping up.

What is the most common reason for failing the 4G?

Puddle sag causing overlap is the most common visual failure — the puddle runs and flows over the base metal, which is an automatic rejection. For bend test failures, incomplete root fusion is most common. Third most common is undercut at the cap toes. Arc strikes outside the weld zone are an automatic visual rejection and happen more overhead due to repositioning during welding.

What plate thickness gives unlimited qualification?

A 1-inch (25mm) ASTM A36 plate qualifies for unlimited production thickness per D1.1 Table 6.11. A 3/8-inch plate only covers up to 3/4-inch production thickness. Always use 1-inch plate unless the project is specifically limited to light material.

Can I mail in my 4G test plate?

Yes. AWS D1.1 does not require the CWI to witness the welding. Your welder completes the overhead plate at your shop under a qualified WPS, ships it to WeldCertTest, and our CWI performs visual inspection followed by accredited bend testing. This is fully code-compliant and our standard service.

How long does the certification stay valid?

Valid indefinitely per D1.1 Clause 4.25 as long as the welder uses the qualified process at least once every six months. The employer maintains a continuity log. Qualification expires if six months passes without using that process — retesting required.

Does the 4G qualify fillet welds?

Yes. The 4G groove weld test qualifies fillet welds in 1F (flat), 2F (horizontal), and 4F (overhead) positions per D1.1 Table 6.10. A separate fillet weld test is not required. Note: 3F vertical fillet is not covered by the standalone 4G — it requires the 3G or 3G/4G combined test.

What if the welder fails the 4G test?

Per D1.1 Clause 6.25, a retest is permitted after additional practice if the failure is due to lack of skill. A fresh plate must be welded — the failed plate cannot be resubmitted. Contact us to review the failure mode before retesting. Knowing whether it was a visual rejection or a specific bend specimen failure helps focus the practice session before the next attempt.

Do I need a WPS for the 4G test?

Yes. D1.1 requires the welder to test under a qualified Welding Procedure Specification. WeldCertTest provides a WPS with each test, or you may use your company's existing D1.1 prequalified WPS. The WPS is referenced on the WPQ record.

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4G Overhead Plate Qualification