3G and 4G Welding Explained: Vertical and Overhead Positions, Certification, and Technique

Why 3G and 4G Welding Are the Real Test of a Welder

Your flat beads look like they came off a brochure. The machine is dialed in, the joint is clean, and every pass lays down smooth and even. Then your foreman points to an overhead V-groove above your head and says the inspector shows up at four o’clock. Gravity is no longer your friend. Heat wants to sag, the puddle wants to fall, and suddenly the skill you built on a bench gets tested for real. That jump from flat plate to vertical uphill and straight overhead is where welders find out what actually holds up.

3G and 4G welding sit at the center of that test. They are position codes, and they matter because the position changes almost everything: how fast you travel, how you hold the electrode or torch, and how much control you have over a puddle that is actively trying to escape.

What 3G and 4G Actually Mean

The letters and numbers come straight from AWS A3.0M/A3.0 Standard Welding Terms and Definitions, where G stands for groove weld and F stands for fillet weld. The digit tells you the position: flat (1), horizontal (2), vertical (3), and overhead (4); 1G through 6G simply extend that logic to pipe. So 3G is a vertical groove weld, and 4G is an overhead groove weld.

Why These Positions Expose Weak Technique

On flat work, gravity helps you. The puddle sits in the joint, you can see everything, and your body is relaxed. Rotate the same joint to vertical and you are fighting a puddle that wants to run downhill while you climb uphill. Flip it overhead and gravity pulls the entire molten pool away from the joint, toward your face and your arms. That is why overhead (4G) is widely considered the most physically demanding single-position plate test there is. See Miller’s overview of the four basic welding positions.

Access makes it worse. Overhead work means hot spatter falling on your shoulders, arms, and hood. Vertical uphill work often means awkward reach and a narrow window to watch the puddle. When gravity, access, and body position all stack against you at once, sloppy technique that flat welding hides gets exposed.

What This Guide Covers

This article walks through everything that matters for 3G and 4G work:

• The full AWS position system, including 5G and 6G
• Step-by-step technique for vertical uphill welding
• Puddle control when you are welding overhead
• Settings, electrode choices, and process selection
• Qualification and testing under AWS D1.1
• Common defects and how to avoid them
• Career value, training plans, and safety

The career angle is real. AWS data estimates the U.S. welding workforce at roughly 771,000 professionals, with about 320,500 new welders needed by 2029. Code-qualified welders who can pass a 3G or 4G test are exactly the people employers chase, because those positions show up constantly in structural and pipeline work.

Positions also shape pay and employability. Structural steel, pressure piping, shipbuilding, and field erection all rely on vertical and overhead welds, so a welder limited to flat and horizontal work has a much smaller pool of jobs. The U.S. Bureau of Labor Statistics tracks welders, cutters, solderers, and brazers as one occupational group, and demand stays tied to construction and repair work that rarely happens in a comfortable flat position.

Along the way, we’ll touch on how consumables and setup feed into position work, from contact tip selection to wire feed consistency, because a weld that fails in a vertical test is often a setup problem wearing a technique costume.

If you are still building your fundamentals, a solid plan for welding practice pays off before you chase a code. But once flat work feels easy, vertical and overhead are the next honest benchmark. Let’s break down the positions first.

The AWS Position System: 1G, 2G, 3G, 4G, 5G, and 6G Decoded

In welding’s position numbering, the number tells you where the joint sits in space; the letter tells you what kind of joint it is. G stands for groove, F stands for fillet. So 3G is a groove weld made in the vertical position, while 3F is the fillet version of that same vertical orientation. Miss the letter and you can misread an entire qualification record.

These designations are not shop shorthand. They are the language of qualification testing used in codes like AWS D1.1, and they show up on the Welding Procedure Specification (WPS) and on a welder’s certificate. If you want a clean overview of how positions fit into the wider skill picture, our guide to welding practice is a good companion.

Every position label answers the same two questions: is the joint a groove or a fillet, and how is it oriented in space? A “2G” on a drawing tells the fabricator the joint is horizontal; a “4F” tells the welder it is an overhead fillet. That is the whole logic of the system — encode orientation and joint type into a short code so a WPS, a test record, and a shop drawing all speak the same language.

Plate Groove Positions: 1G to 4G

For plate, four groove positions cover the common ground:

Fillet welds reuse the same four numbers with an F: 1F flat, 2F horizontal, 3F vertical, and 4F overhead. The distinction matters because fillet and groove coverage are tracked separately in AWS D1.1. Passing a 3G groove test does not automatically clear you for 3F fillet work, and it doesn’t work the other way around either. The code treats them as different qualifications.

Pipe Positions: Same Letters, Different Geometry

Pipe throws a wrinkle into the system because the pipe can be rotated or locked in place, and that changes everything about difficulty:

• 1G pipe is rolled on turning rollers so the weld stays in the flat position while the pipe spins under the arc.
• 2G pipe is fixed with its axis vertical, so you run a horizontal bead around a joint that won’t move.
• 5G pipe is fixed horizontal; the welder has to carry the bead through flat, vertical, and overhead in one continuous pass around the circumference.
• 6G pipe is fixed at roughly 45 degrees, forcing the welder through every orientation in a single joint. It is the broadest of the common pipe qualifications.

The position numbering system is consistent across plate and pipe, but the geometry of a fixed pipe makes the same number far harder to earn. Miller’s overview of the basic welding positions reinforces why orientation, not just joint type, drives difficulty.

“Higher Number Means Harder” Is a Guide, Not a Rule

It’s tempting to rank positions 1 through 6 as a difficulty ladder, and in practice the higher numbers usually are tougher — a rolled 1G pipe is a breeze next to 6G. But that is a rough rule of thumb, not a code rule.

Under AWS D1.1, position scope is defined by the positions you actually tested. A code table governs coverage, not intuition. Passing 4G does not quietly grant you 5G or 6G, and those written rules — not your gut or your foreman’s — decide which joints you can legally weld and sign off on. Think of the number as a hint about difficulty, never as a substitute for reading the coverage table.

3G Vertical Welding: Technique for Welding Uphill Against Gravity

3G is the position where gravity stops being a spectator and starts working against you. In a 3G groove weld, the plate stands vertically and the joint axis runs vertical too, so the molten puddle wants to sag, drip, and slide down the face before it freezes. You either fight it uphill or let it fall downhill — and the choice you make changes the weld you get.

Uphill Is the Structural Default

Most code work calls for vertical-uphill. Traveling bottom to top forces heat into the sidewalls and drives molten metal ahead of the arc, producing deeper sidewall fusion and a narrower, stronger bead. On thicker sections that fusion is the whole point, so vertical-up dominates structural procedures.

Vertical-down is a different animal. It runs faster and looks smoother, but it lays metal on top of cold steel with shallow penetration and a real risk of lack of fusion. Because of that, AWS D1.1 treats vertical-up and vertical-down as distinct essential variables for both procedure and performance qualification (see how qualification works) — one test does not cover the other. Unless a qualified WPS explicitly authorizes downhill, assume the job is uphill.

There’s real value in that: a 3G test on 1-inch plate can qualify a welder from 1/8 inch to unlimited thickness, depending on the code edition and WPS, which is why it’s one of the most useful tests to chase (plate qualification details).

Root Pass Strategy

The root sets everything. On an open root, keep the gap and land consistent, watch the keyhole, and let the arc bite both edges before you move. A slight side-to-side motion helps you read the keyhole without blowing through. For a closed root, focus on full fusion into the corner and avoid cold lap and overlap.

Stringer or Weave?

Beginners should build skill with stringers. A straight drag with little to no oscillation is easier to keep consistent and keeps heat input low, which tames sagging. Weaves are reserved for fill and cover, and even then narrow is safer — keeping the weave within about three electrode diameters for stick welding prevents the puddle from outrunning the arc at the edges.

Angle, Arc Length, and Travel Speed

For a 3G groove, a 90-degree travel angle — electrode perpendicular to the plate — is the common starting point, though a few degrees of push or drag changes penetration. A 3F fillet typically uses about a 45-degree angle instead, so don’t carry your fillet habits into a groove.

Keep the arc short. A long arc widens and cools the puddle, encouraging undercut and a rough face; a tight arc concentrates heat and gives you control. Travel speed then governs bead shape: too fast and you get a thin, crowned, poorly fused pass, too slow and the puddle overheats and sags.

Managing Heat Input

Heat input is current times voltage divided by travel speed, and in 3G it’s a balancing act. Enough heat gives you that sidewall fusion; too much and the plate warps or the root drops out. Adjust amperage within the electrode maker’s range — the settings and polarity you’d dial for 3/16 E7018 are a useful reference — and let travel speed fine-tune the rest.

Use the Shelf

Here’s the trick that separates smooth 3G welds from ugly ones: the shelf. Each bead you deposit becomes a ledge that supports the next puddle. On a vertical-up root, the metal just below the arc holds the puddle in place so it doesn’t sag. On fill passes, the previous bead’s toe gives the new puddle something to sit on. Weld into that shelf, let it carry the weight, and the puddle behaves. Fight it by pushing too fast or weaving too wide, and gravity wins.

None of this comes from reading alone. Vertical technique lives in muscle memory, so repeatable welding practice on scrap plate is what actually builds the control.

4G Overhead Welding: Controlling the Puddle From Below

Overhead welding is classified as 4G on a groove joint. The plate sits horizontally above your head, the groove opens downward, and you deposit metal up into a joint that is fighting to rain straight back down. Of the single-position plate tests in structural welding, 4G is widely considered the most physically demanding — it drains your arms, punishes sloppy technique, and leaves nowhere to hide. If your flat and vertical beads are clean, this is the position that still finds the weak spots.

Why the Root Pass Is the Hardest Part

The root is where most 4G attempts fail. You are closing a downward-facing gap with no shelf to hold the molten pool, so the puddle wants nothing more than to drip out the bottom of the joint. The correction is counterintuitive: reduce heat and travel faster. Crank the amperage up and the puddle widens until gravity wins. Run it cooler and smaller, and the metal freezes before it sags.

The physics come down to surface tension versus gravity. Molten steel behaves like a thin film: its own surface tension pulls the puddle together and holds it against the underside of the plate, while gravity drags it downward. As long as the puddle stays small and cools quickly, surface tension wins. Let it grow, overheat, or run a long arc, and gravity takes over — you get a convex sag, lack of fusion, or a hole burned straight through.

That balance is the whole game in overhead work. On plate, welders often run E7018 at 1/8 inch because it fills fast. Overhead, dropping to a 3/32-inch E7018 gives finer puddle control and a bead you can actually steer. If you are dialing in rod amperage, the same logic behind 3/16 E7018 amperage settings applies, just at a smaller scale and with less margin for error.

Tight Arc, Cooler Settings, Faster Travel

Three habits separate a passing overhead weld from a puddle on the floor:

• Short arc. A long arc lets the puddle sag and throws spatter. Keep the electrode tip almost touching the metal.
• Reduced amperage. Back off roughly 10–15% from your flat setting so the deposit solidifies quickly. Every extra degree of heat is a degree the metal spends sagging instead of freezing.
• Controlled speed. Move steadily and slightly faster than on flat plate, watching the puddle edge rather than the arc.

Overhead grooves are usually filled with several stringers rather than one big weave. Narrow beads let each pass freeze before the next, which keeps heat input low and the profile under control. Weave the rod side to side and the puddle grows too large to hold.

Body Position, Bracing, and Spatter

Because you cannot see as easily and your arms tire fast, brace both forearms against the work or a support before you strike an arc. Lock your body in so the only movement is your hand and a slight wrist rotation. Loose arms wander, and a wandering electrode overhead means lack of fusion.

Spatter also falls on you in 4G. A leather jacket, cape, and a proper helmet are not optional, and OSHA’s welding regulation on protective clothing exists largely because of positions like this. For eye protection specifics, see protective eyewear for welding. The 4G SMAW overhead qualification exists precisely because this position is unforgiving.

Why Strong 3G Welders Fail 4G

Vertical uphill (3G) lets gravity help your puddle settle. Overhead reverses that relationship entirely: gravity is now your enemy, and the techniques that worked uphill — longer arc, more heat, slower travel — betray you. Welders who pass 3G easily often fail 4G on the first try because they never rebuilt their muscle memory for a tight arc and a cool puddle. Repetition under real overhead conditions fixes it; a structured welding practice routine is the fastest route.

AWS classifies these positions for a reason; the four basic welding positions map directly to how gravity changes the physics of the puddle.

Qualification and Certification: Passing the AWS D1.1 3G/4G Test

Two pieces of paper get tangled together in every shop conversation, and they are not the same thing. One is the welder qualification record, or WPQ. The other is the AWS Certified Welder card. The gap between them decides whether your credential travels with you or stays with your employer.

A WPQ is employer- and code-specific. Your employer qualifies you to a written welding procedure specification (WPS), watches you weld a test coupon, and signs a record confirming you can produce sound welds to that procedure. That record lives with the company and does not travel with you.

An AWS Certified Welder card is portable. You test at an AWS-accredited facility against a published standard, and the result enters a national registry. Even then, a hiring shop must still qualify you to their WPS, because the card proves you passed a test, not that their procedure matches it. Certification bodies spell out that distinction plainly.

The 3G/4G Test Coupon, Piece by Piece

The plate test under AWS D1.1 is standardized, so a 3G test in one city looks like a 3G test a thousand miles away. The coupon is typically 1-inch thick ASTM A36 with a single-V groove, a 45-degree included angle, and a 1/4-inch root opening backed by a steel backing bar. That groove is a complete joint penetration (CJP) configuration.

The 3G coupon is welded vertically, uphill, against gravity. The 4G coupon is welded overhead, puddle fighting gravity the whole way. On the combined test, you weld one coupon vertical and one overhead, using the same process and procedure throughout.

Before anything gets bent, a Certified Welding Inspector (CWI) conducts a visual examination. Arc strikes outside the weld zone, excessive undercut, surface porosity, and poor bead profile can end the test right there — no bending required. Inspector acceptance criteria follow the code closely, and there is no negotiating with them.

Guided Bend Testing: Eight Specimens, Zero Room to Hide

The destructive test is a guided bend. Each plate yields four bend specimens — two face bends and two root bends. On the combined test that is two plates, eight specimens total, and all eight must pass. The straps are bent 180 degrees around a plunger sized to the thickness, stretching the weld metal and heat-affected zone to expose internal flaws.

Open defects above a small threshold (typically 1/8 inch in any direction) fail the specimen. The most common culprits are incomplete fusion at the root, slag inclusions trapped between passes, and porosity.

What Each Qualification Actually Covers

Here is where welders get surprised: a qualification is not a blanket license for every position.

The combined 3G/4G test on 1-inch plate qualifies you for groove welds in 1G, 2G, 3G, and 4G, plus fillet welds in 1F through 4F, with unlimited thickness. That breadth is why employers want it.

But a standalone 4G qualifies 1G, 2G, and 4G — and not 3G vertical. Flip it around: a standalone 3G qualifies 1G, 2G, and 3G, and not 4G overhead. Every position must be demonstrated separately.

ASME Section IX Parallels

Move into pressure vessels or piping and you will meet ASME Section IX instead of AWS D1.1. The logic is nearly identical: a performance qualification test, visual inspection, and guided bend specimens that must all pass. What changes are the essential variables — base metal grouping, filler classification, position, and thickness ranges — and the continuity rules. The skill transfers; the paperwork does not.

Common failure causes hold steady across both codes: incomplete fusion at the root, slag inclusions, undercut, arc strikes outside the weld zone, and overhead puddle sag. Build fundamentals on the bench with a structured welding practice routine and the coupon stops being a gamble.

Settings, Electrodes, and Process Choices for 3G and 4G Work

Getting certified in 3G and 4G is one thing; making production welds that match the test is another. The gap usually comes down to settings and consumables. Choose the right process, dial it in correctly, and gravity becomes a manageable nuisance instead of an enemy.

SMAW: E7018 Does the Heavy Lifting

Shielded metal arc welding remains the default for structural vertical and overhead work. E7018 is a low-hydrogen, iron-powder electrode that lays smooth, strong beads and resists cracking in restrained joints — the reason it dominates AWS D1.1 qualification tests. Store it in a rod oven, and keep the joint clean: moisture, oil, and rust all invite porosity.

Run E7018 on electrode-positive (DCEP) polarity. Typical amperage: about 90–115 A for 3/32 in, 110–150 A for 1/8 in, and 150–190 A for 5/32 in. For vertical-up and overhead, stay at the bottom of those ranges, use a short arc, and hold a slight upward drag angle so the puddle stays put. For a deeper breakdown, see our guide to 3/16 E7018 amperage settings.

FCAW-G and FCAW-S

Flux-cored arc welding deposits metal fast and handles mill scale better than GMAW. Gas-shielded FCAW-G uses a shielding gas, usually CO2 or a CO2/Ar mix, and runs well vertical-up on thicker plate with strong penetration and high deposition. Self-shielded FCAW-S needs no gas, which makes it handy outdoors — the same principle behind gasless MIG. On overhead passes, most operators trim wire feed speed and voltage a little to keep the puddle from dropping out.

Polarity trips up a lot of welders here: most self-shielded wires run DCEN, while gas-shielded wires usually run DCEP. That single swap changes penetration and bead shape more than most people expect. Get it backwards and the arc sputters instead of welding. Our explainer on flux core polarity covers which wire wants what.

GMAW Short-Circuit for Thin Material

MIG with short-circuit transfer is a favorite in vertical and overhead positions because lower heat input keeps the puddle from sagging. A 75/25 argon-CO2 mix with 0.030 to 0.035 in wire is a common setup for thin plate. Voltages land around 16–20 V with wire feed speeds of roughly 150–250 in/min depending on thickness. Keep the gun angle tight and travel steady.

A clean, correctly sized contact tip makes or breaks this. Worn tips cause erratic feeding and cold lap, so review contact tip selection and maintenance if your arc keeps wandering.

TIG occasionally appears on precision 3G and 4G joints. It runs DCEN on carbon steel, which you can dig into in our guide to TIG welding polarity.

The WPS Is the Boss

None of these numbers are yours to invent on a certified job. Every production weld must follow the parameters listed in the approved Welding Procedure Specification, as OSHA’s welding standard requires. Amperage, voltage, polarity, travel speed, and electrode type are essential variables — change one and you can invalidate the qualification entirely. A qualified WPS removes guesswork and protects you when the inspector shows up.

So treat your settings as a small part of a larger skill. Building the judgment to hold those parameters on a vertical-up root or an overhead cover pass takes deliberate repetition, which is exactly what structured welding practice develops. Know the WPS, respect the ranges, and the machine becomes a tool instead of a variable.

Common Defects and Mistakes in Vertical and Overhead Welds

Gravity is a saboteur in 3G and 4G work. In flat position it pulls the puddle into the joint; uphill and overhead, it drags molten metal away from where you want it. That single difference explains why the same wire, same machine, and same steady hand produce rejects in vertical and overhead welds that would pass easily on a table. Here are the defects inspectors look for first, and the mistakes that create them.

Lack of Fusion: The Silent Coupon Killer

Incomplete fusion happens when the arc fails to melt the base metal or the previous bead before the filler freezes on top. In vertical uphill, fast travel and a puddle that runs ahead of the arc leave cold, unbonded sidewalls. In overhead, the puddle sags away and the arc struggles to bite into the root.

Incomplete fusion at the root and to the backing bar is one of the top causes of bend-test failure on 3G and 4G coupons. Visual inspection often misses it, which is why qualified welders push amperage, pause at the toes, and let the arc do the melting. Wire-feed welders who fight this should also check torch angle and contact tip condition, since a worn tip throws the arc off line.

Slag Inclusions From Sloppy Interpass Cleaning

Slag inclusions are pockets of flux trapped between passes or along the sidewall. They almost always trace back to inadequate interpass cleaning, which is especially critical in the tight overhead groove where a chipping hammer barely fits. Slag that hides behind a heavy crown on one pass gets buried by the next. Slow down and clean to bright metal before laying the next bead.

Undercut at the Weld Toes

Undercut is a groove melted into the base metal at the weld toe that the filler never fills back in. It forms when travel is too fast, amperage is too high, or the arc lingers at the edge. Undercut exceeding the code limit, commonly 1/32 inch on many structural criteria, will fail inspection because the notch concentrates stress and invites cracking. Inspectors measure it to the deepest point with a weld gauge, so a few thousandths decide pass or fail.

Overlap, Excessive Crown, and Burn-Through

Overlap is cold metal rolled over the base metal without fusing, common in slow uphill travel or vertical down where the puddle outruns the arc. It looks like a weld but bonds to nothing, which is why it counts as a defect. Our guide to the overlap welding defect breaks down causes, detection, and repair.

Excessive crown or convexity is the opposite problem: a bead so tall and rounded it can hide incomplete fusion underneath. Too much wire, too little voltage, and slow travel build that steep profile.

Burn-through happens when the root opens and the arc punches a hole through the plate. Wide root gaps, too many amps, and a sluggish root pass are the usual culprits in 4G, where the puddle has no shelf to rest on.

Porosity and Arc Strikes

Porosity appears as pinholes or wormholes where gas was trapped as the puddle froze. In vertical and overhead work, the causes are a long arc, damp electrodes, dirty metal, and shielding gas blown off by shop draft. Overhead is the worst position for shielding, so gas flow and nozzle angle matter more than ever.

Arc strikes outside the weld zone are treated as an automatic visual rejection because they can create hard, crack-prone zones in the base metal. Tapping a rod or stubbing a wire on the plate to restart leaves a scar that no amount of grinding fully erases.

Learning to catch your own defects before the inspector does is a core skill. Compare finished beads against our good and bad MIG welds guide, and use the drills in welding practice to build consistency.

3G vs 4G vs 5G and 6G: Choosing the Right Qualification

When an inspector asks for your qualification card, the letters and numbers matter far more than most welders realize. The difference between a 3G and a 6G can be the difference between welding a handrail in a shop or qualifying for a cross-country pipeline. With testing costs rising, the smartest move is to pick the test that covers your work with the least spend. To do that, you need to know how coverage works under AWS position standards.

Plate Qualifications: What One Test Will Cover

For structural steel, plate tests follow a simple rule: the steeper the position, the more work it unlocks. A flat 1G covers only flat, while a horizontal 2G covers flat and horizontal. From there, vertical and overhead do the heavy lifting. The 3G is the most cost-effective single-plate qualification because one plate covers three groove positions and three fillet positions. By contrast, the combined 3G/4G test is the broadest single plate qualification available under AWS D1.1 Table 6.10, covering flat, horizontal, vertical, and overhead for both grooves and fillets.

This coverage logic is why many shops push new welders toward 3G first. It opens doors to most structural jobs without paying for a second coupon. For those looking to sharpen their skills before testing, Welding Practice: The Complete Guide to Building Real Welding Skills can help dial in puddle control before the clock starts.

Pipe Qualifications: 5G and 6G

Once you leave plate for round stock, the game changes. Pipe positions are rated 1G, 2G, 5G, and 6G, and they do not map directly to plate. The 5G is a fixed horizontal pipe weld, while the 6G is the infamous “45-degree” fixed pipe that forces you to weld in all positions at once. A 6G pipe qualifies all pipe positions, but plate and pipe qualifications are tracked separately under different code provisions. In short, a 6G card will not automatically cover a plate WPS unless the code and contract allow it.

These tests demand tight fit-up and precise settings, especially for processes like flux-cored welding or TIG. For high-deposition work, some contractors also factor in automation, such as robotic submerged arc welding, but manual quals still rule most field calls.

Matching the Test to the Job

Cost-effectiveness comes down to where you will spend your hours. For a fab shop, most work is flat, horizontal, or vertical, so a 3G (or 3G/4G) on plate will cover the bulk of it. For field erection, overhead becomes common, and adding 4G pays off if you already hold 3G. For pipeline work, 5G or 6G on pipe is non-negotiable, as structural plate quals will not satisfy most pipeline codes.

In the end, do not chase the hardest test for bragging rights. Chase the one that matches your next paycheck. If you need to cover the widest range of structural work for the least money, start with 3G. If you need to cover everything on plate, take the combined 3G/4G. If the job runs on pipe, only 5G or 6G will do.

Practical Training Plan, Safety, and Career Value

Skill at 3G and 4G isn’t talent, it’s reps. The standard training order for plate climbs 1G, then 2G, then 3G, then 4G, introducing one gravity problem at a time. Skip a step and you’ll fight two variables at once, which slows learning and builds bad habits.

A Practice Progression That Actually Sticks

1. 1G flat. Lock in travel speed, drag angle, and a steady bead on flat plate before anything gets harder. Our guide to building real welding skills covers how to structure these early sessions.
2. 2G horizontal. Now the puddle wants to sag. You learn to watch the toe lines and read the freeze.
3. 3G vertical. Uphill forces you to control heat and pause rhythm; this is where most welders grow fastest.
4. 4G overhead. The hardest plate position. Keep the arc tight, the puddle small, and your body braced.
5. Fixed pipe. Progress to 5G and 6G only after plate positions feel automatic.

Each coupon should be a single-V groove, 30 to 37 degrees per bevel, with a root gap and backing strip that matches your test standard. Clean to bright metal, tack square, and label every coupon with date, process, and settings so you can track progress.

Keep sessions short and deliberate. Weld a coupon, cut it, inspect the cross-section, then adjust one variable at a time: amperage, angle, or travel speed. A cheap angle grinder and a bandsaw turn each coupon into a lesson, and a notebook of settings beats guessing when test day arrives.

Self-Inspection Between Tests

Before you pay for a certified test, inspect your own work like an inspector would. Run a visual pass for undercut, overlap, and excessive reinforcement. Bend-test scraps if you can, watch for porosity and lack of fusion on the break, and photograph defects so you recognize them next time. A well-planned shop layout with good light and a dedicated practice bay makes this routine far easier.

Safety: The Part Overhead Welders Can’t Ignore

Overhead work throws molten spatter straight down. Wear full leathers (jacket, sleeves, cape, and skull cap) plus approved eye protection under a helmet with the right filter shade. Button every collar and cuff so spatter can’t funnel in.

Fume control matters as much as burn protection. Welding fume exposure is regulated under OSHA 1910.252 and 1926 Subpart J; local exhaust and respiratory protection are the common controls. Ventilation isn’t optional: weld in a booth with local exhaust at the arc, and keep your head out of the plume. Where fume can’t be captured at the source, a powered air-purifying respirator or a supplied-air hood becomes essential, especially on stainless, galvanized, and painted steel. Keep a fire watch on hot work, keep a charged extinguisher within reach, and shield nearby workers from arc flash.

Why These Skills Pay

Vertical and overhead ability is what unlocks field erection, ironwork, shipyard, and pipeline work, the jobs that pay above shop rates. Demand is strong: AWS estimates roughly 320,500 new welding professionals will be needed in the U.S. by 2029, about 80,000 openings a year. Yet only about one new welder enters the field for every two experienced welders retiring, worsening the skilled-welder gap. Certifications such as 3G and 4G plate, or 6G pipe, are often the gate to those roles, and many employers screen on them directly. For context, the BLS tracks welders, cutters, solderers, and brazers as a large occupational group where certifications command higher pay.

Put in the practice hours, certify on 3G and 4G, and you’re not just a better welder. You’re a more employable one.

Conclusion: Turning Vertical and Overhead Into Your Advantage

Here is the mindset shift worth carrying out of this guide: 3G and 4G are definitions of position, not rankings of difficulty. They tell you where the joint sits in space, vertical for 3G and overhead for 4G, and everything else follows from that geometry. Gravity stops working with you, and your technique has to compensate. Once you accept that framing, the fear around these positions shrinks into something you can practice.

The practical goal for most structural welders is the combined 3G/4G qualification. Pass that test and you are cleared for all plate groove and fillet positions, plus unlimited thickness on a 1-inch test plate. On that plate, thickness is irrelevant: you have proven you can fuse sound groove welds in every position the code cares about. That single credential opens doors a flat-and-horizontal welder simply cannot walk through.

The Technique in Four Words

Everything covered in the earlier sections condenses into a handful of habits:

• Tight arcs: keep the electrode or wire close so the arc stays stable and the puddle stays where you put it.
• Controlled heat: travel speed and amperage work together; too much heat and the puddle sags, too little and you get cold lap.
• Small puddles: a compact molten pool is a manageable one, especially straight overhead.
• Relentless interpass cleaning: slag left behind becomes trapped slag, porosity, and a failed inspection.

Technique only sticks through deliberate repetition. Shielded metal arc work with a rod like E7018 rewards you for reading puddle behavior and adjusting in real time, and the 3/16 E7018 amperage settings you dial in upright will change the moment you roll to overhead. A structured approach to building real welding skills beats random hood time every time.

Nothing exposes a buried bad habit faster than an overhead bead, and nothing teaches puddle control like vertical uphill. Learning to read the surface of a finished weld, spotting undercut, overlap, or a wandering bead before an inspector does, is part of the same education, and our guide to telling good and bad MIG welds apart is a useful companion.

Why This Skill Pays

Vertical and overhead capability is what separates shop-only welders from structural fabricators and field erectors. It is the difference between running beads on a bench and climbing into a position where the work actually needs doing. Demand for certified, code-ready welders continues to outpace supply across construction, energy, and manufacturing, a shortage documented year after year in industry workforce data and echoed in the BLS outlook for welders. Employers cannot hire skill that does not exist, and they pay a premium when they find it.

So treat vertical and overhead as leverage, not a hurdle. Practice them on purpose, respect the code, keep your certs current, and read every WPS like it holds the answer, because it usually does. Keep a notebook of which settings held up in which position, and let the evidence guide your next pass. That is how technique becomes instinct. The welders who can hold a clean overhead bead when the inspector is watching are the ones who get called back, moved up, and paid accordingly.

Frequently Asked Questions

What is the difference between 3G and 4G welding?

3G is a groove weld made in the vertical position, with the plate standing upright and the weld usually progressing uphill. 4G is a groove weld made in the overhead position, with the plate horizontal above the welder and the weld deposited from below. Under AWS D1.1 they are separate skills, so passing one does not automatically qualify you for the other.

Does a 3G certification cover 4G welding?

No. Per AWS D1.1, a 3G qualification covers flat (1G), horizontal (2G), and vertical (3G) groove welds plus fillet positions 1F, 2F, and 3F. Overhead groove (4G) and overhead fillet (4F) require a separate 4G test or the combined 3G/4G qualification.

Does a 4G certification cover 3G vertical welding?

No, and this surprises many welders. A standalone 4G qualifies flat (1G), horizontal (2G), and overhead (4G) groove welds, plus 1F, 2F, and 4F fillets. It does not cover 3G vertical or 3F vertical fillet, because the code treats vertical as a distinct skill.

Which is harder, 3G or 4G welding?

Most welders find 4G overhead harder. The puddle hangs directly over the arc, spatter falls on the welder, body position is awkward, and the root bead wants to sag. 3G vertical is also demanding because gravity fights the puddle, but it is generally considered easier than overhead for most people.

What electrode is best for a 3G and 4G test?

E7018 is the standard low-hydrogen SMAW electrode for structural 3G and 4G qualification tests under AWS D1.1. Many welders use 3/32-inch E7018 for the root and overhead passes because the smaller electrode gives better puddle control, then switch to 1/8-inch if the WPS allows it.

How thick a plate do I need for unlimited thickness qualification?

A 1-inch test plate typically qualifies from 1/8 inch up to unlimited thickness under AWS D1.1. Thinner coupons, such as 3/8-inch plate, generally qualify a much narrower thickness range, so most structural welders test on 1-inch material.

Why do so many welders fail the 4G test?

The root pass is the usual culprit. Incomplete fusion to the backing bar, slag trapped in the tight groove, undercut at the toes, and overhead sag that produces overlap all cause bend-test failure. Fatigue and poor body bracing also lead to inconsistent travel speed and arc length.

Is vertical-down allowed in 3G welding?

Generally no for structural plate under AWS D1.1 unless a qualified WPS specifically authorizes it. Uphill and downhill are treated as distinct essential variables, so a test in one direction does not qualify you for the other. Some thin-material and pipe procedures do allow vertical-down.

Do I need 3G and 4G for structural field work?

If your work involves both vertical and overhead groove welds — common in ironwork, structural steel erection, and field fabrication — you need both. Many contractors require ‘all-position certified,’ which the combined 3G/4G test satisfies and neither standalone test does.

Authoritative Sources & Further Reading

• https://www.aws.org/magazines-and-media/welding-digest/2025/october/wd-oct-2025-where-are-the-welders
• https://weldingworkforcedata.com/
• https://www.thefabricator.com/thewelder/article/arcwelding/outlook-trends-and-pay-for-the-welding-workforce-according-to-aws-data
• https://www.millerwelds.com/resources/article-library/what-are-the-4-basic-welding-positions-and-when-should-you-use-them
• https://www.machinemfg.com/what-does-1g-2g-3g-4g-5g-and-6g-mean-in-welding/
• https://gowelding.org/welding-certification/
• https://gowelding.org/welding-certification/4g-smaw-overhead/
• https://weldcerttest.com/3g-4g-plate-qualification.html
• https://www.bls.gov/ooh/production/welders-cutters-solderers-and-brazers.htm
• https://www.osha.gov/welding-cutting-brazing
• https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.252
• https://www.cdc.gov/niosh/topics/welding/default.html