Is Stick Welding Stronger Than MIG? The Complete Strength Comparison

Is Stick Welding Stronger Than MIG? The Short, Honest Answer

Walk into any fabrication shop and you’ll hear it. One welder swears by his old buzz box and a stack of 7018 rods, insisting stick is the only process that lays down real strength. Another points to his MIG gun and says his wire welds are every bit as strong and twice as fast. Both have war stories about welds that held under a loader bucket and welds that snapped on a trailer hitch. So who’s right?

Here’s the short answer: neither process is inherently stronger. As-welded strength comes from the filler metal classification, joint design, penetration, fusion, and freedom from defects. It does not come from the name stamped on the front of the machine. Run stick (SMAW) and MIG (GMAW) to the same code on clean steel, and their tensile strength is essentially identical.

Why the Numbers Come Out the Same

Look at the two consumables most often compared. E7018 stick electrodes and ER70S-6 MIG wire both carry a 70 ksi (70,000 psi) minimum tensile strength and a 58 ksi minimum yield strength. The “70” in both designations means exactly that. The deposited weld metal is mechanically equivalent, so there is no built-in strength advantage for either process.

Those numbers aren’t marketing claims. AWS filler metal classifications define minimum tensile and yield strength in the as-welded condition. That means the consumable, not the process, sets the baseline. A properly executed E7018 stick weld and a properly executed ER70S-6 MIG weld on A36 plate both pull 70,000+ psi in destructive testing.

Independent research backs this up. Comparative studies of SMAW and GMAW on structural steel repeatedly find that when both pass a qualified procedure, their tensile and yield results land within a few percent of each other. The differences that show up are usually tied to heat input, technique, and part cleanliness, not the torch or stinger itself.

What This Article Will Cover

Because the headline answer is a tie, the useful question becomes: when does one process beat the other? That depends on the job in front of you. Thick versus thin material. Dirty, rusty steel versus clean plate. Outdoor wind and field repair versus a climate-controlled production line. Each scenario shifts the advantage.

Over the next sections we’ll dig into how strength is actually measured (tensile, yield, bend, and Charpy), the four things that really decide a weld’s strength, and a true head-to-head on clean steel. We’ll cover where stick genuinely wins, where MIG genuinely wins, and the physics of penetration, polarity, and transfer modes. You’ll also see what the codes require under AWS D1.1, plus the common mistakes that weaken either process.

If you want to sharpen the fundamentals before we get technical, our guide to building real welding skills is a good place to start. For now, hold onto the core truth: strength is earned at the joint, not chosen at the machine.

How Weld Strength Is Actually Measured: Tensile, Yield, Bend, and Charpy

“Feels strong” and “is strong” are two very different things. A weld can look flawless, pass the eye test, and still snap under load. The only way to know for sure is to measure it. Each test answers a different question about how a weld behaves when it’s pushed. Weld strength is pinned down through a few standardized tests, and understanding them—alongside solid welding practice—separates a real welder from someone guessing.

Tensile Testing: Yield and Ultimate Strength

Tensile testing pulls a welded specimen apart until it breaks, following ASTM E8/E8M procedures. Two numbers fall out. Yield strength is the stress at which metal stops springing back and starts permanently deforming. Ultimate tensile strength (UTS) is the highest stress recorded before rupture. Higher UTS means more resistance to being pulled apart, but it says nothing about whether the weld will crack.

Bend Testing: Ductility Under Strain

Bend tests force a welded coupon over a mandrel to a set angle or radius, per ASTM/ASME criteria. The weld is stretched across its face or root. If it opens up with cracks or tears longer than the code allows, it fails. Bend testing is really a ductility check: it proves the joint can deform without fracturing, which matters more in real structures than raw pull strength. Root bends are especially telling on open-root joints, while face bends target the cap.

Charpy V-Notch: Toughness and Impact Resistance

Charpy V-notch testing swings a weighted hammer into a notched specimen and measures how much energy it absorbs. That number, in joules or foot-pounds, is impact toughness. A 2025 peer-reviewed study of IS2062 E350 steel found Charpy toughness of 235 J for GMAW versus 213 J for SMAW. MIG absorbed more impact energy while stick (SMAW) showed higher tensile strength. Toughness and strength don’t always move together.

Hardness and Microhardness Surveys

Hardness testing maps how the weld, heat-affected zone (HAZ), and base metal respond to the heat cycle. A microhardness survey traces a line across all three, revealing hard, brittle bands or soft, weak zones. A spike in hardness usually signals brittle martensite; a dip signals lost strength. Because heat travels fastest into the base metal, the HAZ can end up harder than both the weld and the parent plate, a common source of unexpected cracking.

Elongation, Ductility, and Why Brittle Welds Fail

Elongation is how much a specimen stretches before breaking, expressed as a percentage. It’s the clearest window into ductility. The same IS2062 study recorded elongation of 25.49% for GMAW and 26.19% for SMAW. A weld with enormous UTS but almost no elongation is a loaded spring waiting to shatter: high strength, zero warning before failure.

The Heat-Affected Zone: Where Welds Usually Fail

Here’s the twist most people miss. The weld bead itself is rarely the weak link. In the IS2062 investigation, most failures occurred in the subcritical heat-affected zone, where grain deformation softens the weldment. Heating steel near the weld grows grains coarser, and coarse grains lower toughness. A separate heat-input study found higher energy input in GMAW created a larger HAZ and a steeper drop in tensile strength than SMAW. The base metal or HAZ often governs failure, not the filler.

Overmatching vs. Matching Filler Strength

Fillers, from stick electrodes to MIG wire, are chosen to match or overmatch the base metal. Matching filler approaches the base metal’s strength; overmatching uses a stronger filler so the weld out-tests the plate. Counterintuitively, an overmatched weld can be safer because failure shifts away from the brittle weld into more ductile base metal. The 2025 study captured this neatly: transverse UTS reached 641 MPa for GMAW and 676 MPa for SMAW. SMAW was stronger in tension, yet its joint still failed nearby in the softened HAZ.

The Four Things That Really Decide Whether a Weld Is Strong

Here’s the uncomfortable truth nobody argues about at the shop: the process is not the biggest variable. Four factors decide whether a joint survives load, fatigue, and time. Get them right with either process and you get strong welds. Get them wrong and you can wreck a weld with a machine worth ten grand or one held together with tape. Picture two welders on the same joint and steel: one sabotages his work with cold lap and a wet rod, the other nails it. You can’t tell which process failed just by looking at the break.

1. Filler Metal That Matches the Base Metal

The filler has to be at least as strong as the steel it joins. Weld 70,000 psi steel with a 60,000 psi wire and the joint is weaker than the plate no matter how pretty the bead looks. That’s why a humble 7018 rod (70,000 psi tensile) beats a mismatched wire every time, regardless of process. Match strength, chemistry, and sometimes toughness. The composition of your MIG wire matters as much as the rod in a stinger.

2. Penetration and Full Fusion to the Root

Strength lives at the root. If the arc doesn’t fuse the sidewalls and reach the bottom of the joint, you’ve built a bridge on sand. Stick tends to run hotter at the same current and digs deeper, which is why it forgives poor fit-up. MIG can match it, but short-circuit transfer on thick, dirty, or gapped steel is where penetration gets shy. Travel too fast and you get lack of fusion you can’t see from the cap. The root pass is also where an inspector’s eyes and an X-ray both land first.

3. Freedom From Defects

Porosity, slag inclusions, lack of fusion, undercut, and overlap all steal strength. Every one is a stress riser. Undercut thins the section; slag trapped in a root pass is a crack waiting to open. Stick brings slag into the equation, while MIG brings gas coverage and wire-feed variables. Neither is immune. Cleaning between passes, correct gas flow, and a steady travel angle remove most of them before they start. A joint full of pinholes fails inspection long before it fails in service, and our guide to good and bad MIG welds shows what to look for.

4. Heat Input and HAZ Control

Heat input governs the heat-affected zone (HAZ), that band of base metal whose grain structure changed because of your arc. Too much heat and you grow grains, soften or harden the zone, and invite distortion and cracking. Too little and you cool fast enough to form brittle martensite in some steels. Travel speed, amperage, and preheat all feed into it. This is the same physics that makes welding hardened steel so fussy.

The Hydrogen Problem Nobody Sees

Hydrogen-assisted cold cracking is the quiet killer. It needs three conditions at once: a susceptible microstructure, a critical hydrogen concentration, and tensile residual stress. Remove any one and the crack doesn’t form. Hydrogen comes mostly from moisture in consumables and coatings:

• Cellulosic E6010/E6011 electrodes: roughly 30–60 ml/100g diffusible hydrogen.
• E7018 dried properly at 350°C: under 5 ml/100g.
• GMAW solid wire: inherently under 3 ml/100g.

So stick can be the higher-hydrogen process, but only if you use the wrong electrode or skip the rod oven. Baking electrodes, storing 7018 in a heated quiver, and keeping wire dry all keep that third condition from lining up. Low-hydrogen stick and solid MIG wire both land in the safe zone.

Put it together and the point is blunt: both stick and MIG can produce X-ray quality, code-passing joints, and both can produce junk. The process hands you a tool. The four factors above decide whether the tool builds something that holds.

Head-to-Head on Clean Steel: Why the Strength Is Basically Equal

Put a stick welder and a MIG welder on the same clean, sound mild steel under ideal conditions, and the finished welds are not just close in strength. They are effectively the same. Weld strength lives in the filler metal’s chemistry and in the welding procedure, not in the badge on the machine. Once you strip away rust, paint, and poor technique, there is very little left for either process to argue about.

The Filler Metal Numbers Are Nearly Identical

Read the data sheets and the debate cools fast. AWS filler classifications build minimum strength straight into the electrode name, and a common stick rod and a common MIG wire line up almost perfectly.

Notice the 70 in both names. That figure promises 70,000 psi minimum tensile strength, and the two consumables match on yield, elongation, and low-temperature impact toughness as well. The guaranteed weld-metal properties are interchangeable.

Both Processes Are Prequalified Under AWS D1.1

Under the AWS D1.1 Structural Welding Code, SMAW and GMAW are both prequalified processes. There is a single notable exception: short-circuit transfer GMAW requires qualification testing because its lower heat input is harder to control on thick or restrained joints. For every other transfer mode, the code treats the two processes as equals.

For fabricators, that means either process can go on structural steel using a compliant WPS, with no stated preference from the code. When both are qualified to the same standard, the process choice does not change the guaranteed strength.

The Weld Metal Overmatches the Steel Anyway

Guaranteed strength rarely depends on process choice, because the weld metal is normally stronger than the steel it joins. Common A36 structural steel has a 36 ksi yield strength, so a 58 ksi weld deposit overmatches it by roughly 60 percent. Even on 50 ksi steel, both electrodes meet or exceed the base metal. Their matching Charpy ratings also mean neither wins on low-temperature toughness. As the TWI comparison of MIG and stick notes, the real differences between the processes sit in productivity, portability, and position — not raw strength.

The “Stick Digs Deeper” Myth

This is where the debate usually turns. Stick welders argue that SMAW digs deeper and therefore produces stronger joints. Penetration, however, is not a property of the process name. It is governed by polarity, amperage, travel speed, electrode angle, and joint preparation. Change the polarity and you change where the heat concentrates, the same principle that shapes TIG welds.

Set up correctly, both processes achieve full penetration. Give either one a proper bevel, root gap, and enough current, and the depth of fusion comes down to technique rather than the machine. A 7018 run at the correct amperage will dig just as deep as the job requires.

The one real caveat is short-circuit MIG, which can cold-lap at the weld toes when travel speed runs too high. That is a setup and technique problem, not proof that MIG is inherently weaker. Learning to read those signs, as covered in good and bad MIG welds, fixes it quickly.

What Peer-Reviewed Comparisons Show

Independent studies comparing the two processes on real steels confirm there is no built-in winner. Research on IS2062 E350 structural steel and on high-carbon steel produced results that sometimes favored SMAW and sometimes favored GMAW, depending on the exact parameters. That mixed outcome is the whole point: strength and toughness follow the procedure, the consumable, and the operator, not the process badge.

Where Stick Welding Genuinely Wins on Strength

On clean, flat, quarter-inch steel in a calm shop, MIG and stick weld strength runs neck and neck. Move the job to a muddy pipeline in a crosswind, add rust and mill scale, or jump to one-inch plate, and the equation flips hard toward SMAW. Stick welding doesn’t just win on convenience in these conditions. It produces a genuinely stronger, more crack-resistant joint.

Thick Plate and Multi-Pass Joints

Stick electrodes drive a deep, digging arc that punches into the base metal rather than riding on top of it. On 1-inch carbon steel plates, a 7018 electrode run at proper current can achieve full penetration that distributes stress across the full joint thickness. That deep fusion is exactly what heavy structural and pressure work demands. MIG can reach similar penetration on thick steel, but only with high current, spray transfer, and the right gas mix. Stick gets there with a buzz box and a rod. Layered multi-pass deposits also let you manage heat input and build thickness gradually, keeping distortion and burn-through in check. If you’re dialing in thicker electrodes, our guide to 3/16 E7018 amperage settings walks through the current and polarity that make it work.

Dirty, Rusty, and Painted Steel

SMAW’s flux coating is a built-in cleaner. As the rod burns, the flux creates a shielding gas and a molten slag that floats contaminants out of the pool instead of trapping them. Rust, mill scale, oil, and light paint don’t derail the weld the way they do a MIG puddle that depends on clean shielding. For repair work on old equipment or field steel you can’t grind, that forgiving nature keeps joint integrity intact.

The Field Advantage: Wind, Weather, and High Restraint

MIG relies on an external gas shield that a breeze blows away, typically above about 5 mph of wind. Stick’s flux coating shields the arc from within, so rain, humidity, and gusting wind barely touch it. Outdoors, that’s not a small edge. A dispersed gas shield causes porosity and lack of fusion, which are strength killers. TWI’s comparison of MIG versus stick welding notes stick’s tolerance for rough conditions, which is why field crews reach for it on pipelines and structural repairs. On high-restraint joints where the metal can’t move as it cools, that reliability matters even more.

Low-Hydrogen E7018: Crack Resistance Where It Counts

Hydrogen is the quiet enemy of strong welds. It migrates into the heat-affected zone and causes delayed cracking, sometimes days after the weld cools. E7018 low-hydrogen electrodes produce under 5 ml/100g diffusible hydrogen when properly dried, making them mandatory for high-carbon-equivalent steels and many pressure applications. On restrained joints and thick sections where residual stress runs high, that low hydrogen content is often the difference between a weld that holds for decades and one that cracks overnight.

Open-Root Pipe with E6010 and E6011

For pipe root passes, cellulosic E6010 and E6011 are the gold standard. Their forceful, penetrating arc blasts through the root gap and keys into the bevel, producing the full-penetration root that pressure piping demands. No MIG setup matches that root-pass authority without backing or special procedures. Strong roots come from disciplined technique, and consistent welding practice is how you develop the hand control it takes.

The Tradeoffs You Pay For

Stick’s strengths come at a price:

• Lower deposition efficiency. SMAW runs about 60–65% deposition efficiency, versus 90–95% for GMAW, because flux and slag burn off the electrode. More of every rod is lost to smoke and coating.
• Slag inclusions. Skip the chipping hammer and wire brush between passes and trapped slag becomes a stress riser and a rejection at inspection.
• Slower travel speed. Each pass takes longer, and electrode stubs mean constant stops to change rods.

None of these compromise strength when the welder cleans properly and runs sound technique. They simply mean stick trades speed and efficiency for ruggedness and reliability in the conditions where strength matters most.

Where MIG Welding Genuinely Wins on Strength

Stick welding has its moments, but there are whole categories of work where MIG (GMAW) delivers the stronger, more reliable result. It comes down to control: a steady wire feed and a continuous arc let you set heat input to what the material can actually handle, rather than fighting an electrode that wants to burn hotter than the job needs. That control is what separates a sound joint from a compromised one. Here is where that advantage is real.

Thin Sheet and Auto Body Work

From 16 gauge up to roughly 1/4 inch, MIG’s controlled heat input is a genuine strength advantage. Stick burns hot and aggressive; on thin sections it over-penetrates, warps panels, and can weaken the base metal around the weld. On 18-gauge automotive steel, MIG welds resist vibration cracking better than stick welds, which tend to burn through and embrittle the thin section they join. Less heat also means less distortion, and less distortion means the joint stays aligned and loaded the way it was designed. If your work lives in sheet metal, MIG is usually the stronger choice by default.

Long Production Runs and Repeatability

Strength is not only about one perfect bead. It is about whether the hundredth weld is as sound as the first. Because MIG feeds wire automatically and the machine holds voltage and wire-feed speed steady, the operator removes a big chunk of human error. That repeatability means fewer voids, fewer lapses in fusion, and consistent penetration part after part. Keeping the contact tip clean and the liner fresh is a small habit that protects that consistency.

In a well-set machine, the relationship between voltage and wire-feed speed is fixed, so once you dial in a good bead you can reproduce it weld after weld. That repeatable fusion is what makes MIG so dependable on a production line or in a shop welding the same joint all day. Deposition efficiency tells the story too: GMAW runs at roughly 90-95%, and because there is no slag to chip between passes, arc-on productivity is about double that of SMAW for the same weld volume.

Aluminum, Stainless, and Other Non-Ferrous Metals

MIG handles aluminum and stainless far better than stick. Stick electrodes for these metals are limited and awkward; MIG gives you continuous wire in matching alloy, cleaner arc starts, and far less spatter. That means sounder fusion and better corrosion resistance at the joint, since a clean, gas-shielded puddle resists the oxidation that degrades stainless over time. For aluminum specifically, matching the right current is half the battle, so it pays to understand how DC welding aluminium works before you commit to a setting.

The Flip Side: Where MIG Strength Falls Apart

MIG is not a magic wand. Its weaknesses are real and worth naming, and they all come from losing control of the process rather than from any flaw in GMAW itself:

• Gas shield failure in wind. Outdoors, a gust blows the shielding gas away and the weld takes on porosity. For field work, gasless MIG and flux-cored welding is the practical fix.
• Dirty metal. Rust, mill scale, and oil contaminate the puddle. Stick’s flux tolerates crud that MIG simply cannot.
• Short-circuit “cold lap.” Short-circuit transfer (GMAW-S) can produce lack of fusion, which is why it is not prequalified under AWS D1.1, especially above about 3/16 inch thickness.

The pattern is clear: MIG’s strength edge is control and consistency on thin, clean, non-ferrous, and production work. Learn the settings properly with a solid guide to using a wire welder, and those welds will hold as well as anything stick can put down in the same spot.

Penetration, Polarity, and Transfer Modes: The Physics Behind the Argument

Strip away the brand loyalty and the shop-floor folklore, and the stick-versus-MIG debate comes down to physics. Polarity decides where the heat lands, transfer mode decides how the filler arrives, and together they shape the penetration profile you actually get. Turn those dials either way and both processes can run shallow or deep.

Polarity Sets Where the Heat Goes

For a fixed current, flipping polarity changes the penetration profile, bead shape, and deposition rate. On steel, both SMAW E7018 and GMAW ER70S-x wires run electrode-positive, or DCEP (reverse polarity), which pushes roughly 70% of the arc heat into the workpiece. That concentration is what drives real root fusion.

Self-shielded flux-cored wire (E71T-11) is the exception. It runs electrode-negative, or DCEN, delivering only about 30% of the heat at the work. The tradeoff is a convex bead and moderate penetration, which keeps the arc stable without external gas. Our breakdown of polarity for flux core welding: DCEN vs DCEP shows how the same flip rewires your troubleshooting.

Think of polarity as choosing which end of the arc gets cooked. Electrode-negative concentrates heat in the electrode, which melts wire fast; electrode-positive drives it into the plate, which drives fusion. That’s why so many “weak” welds trace back to leads swapped the wrong way.

The same heat-balance logic shows up in TIG, where AC is used to break up aluminium oxide while DCEN delivers the deepest penetration — our DCEN, DCEP, and AC TIG polarity guide covers the tradeoffs.

Transfer Modes: How the Metal Crosses the Arc

MIG’s penetration story is really a transfer-mode story, and each mode lays down a different profile:

• Short-circuit: low heat, shallow, broad penetration. Fine for thin sheet, weak fusion at the root of thick plate.
• Globular: larger droplets, moderate penetration, and a rougher, harder-to-steer arc.
• Spray: high current, a fine axial spray, and a deep “finger” of penetration that bites hard into the plate.

Spray transfer needs enough current to cross the transition threshold and, usually, an argon-rich gas to stay stable, which is exactly why it penetrates so aggressively compared to short-circuit. Stick, by contrast, gets its shielding from the flux coating, so there’s no gas mix to tune — the electrode and its coating do the work.

Stick has no named modes, but it has an equivalent dial: amperage. Run a 7018 hotter and penetration deepens; back off and the arc rides the surface. The same logic runs through our 3/16 E7018 amperage guide.

Gas, Current, and Travel Speed Move the Needle

Shielding gas is a penetration control people forget. Switching MIG from 75/25 Ar/CO2 to 100% CO2 deepens and narrows the penetration finger, at the cost of more spatter. Argon-rich mixes tend to spread broader and smoother.

Current, travel speed, and arc length shift the profile too:

None of this is fixed hardware. Technique — steady travel speed, correct arc length, clean plate — does as much for penetration as any machine setting, which is why real welding practice beats spec-sheet arguments every time. Even short-circuit MIG is recognized as prequalified in certain code scenarios, as The Fabricator explains in its article on short-circuit MIG prequalification.

The honest takeaway: “deeper penetration” is a dial both processes can turn, not a fixed property of stick. Stick’s reputation for bite comes from high current on thick steel, not from secret physics MIG can’t reach. Set MIG up in spray transfer on clean plate and it will match — or beat — what a rod does. For a neutral industry summary of how the two processes compare, TWI’s MIG vs stick reference is worth a look.

What the Codes Say: AWS D1.1, WPS/PQR, and Qualified Procedures

Here’s the truth that settles most shop-floor arguments: a weld’s guaranteed strength doesn’t come from the process name on the machine. It comes from a qualified welding procedure. Stick and MIG are both just tools. The paper trail behind them is what makes a weld trustworthy.

The Code That Rules Structural Steel

In the U.S., structural steel welding answers to AWS D1.1, the Structural Welding Code—Steel. It was first published in 1928 as the Code for Fusion Welding and Gas Cutting in Building Construction and has grown into the worldwide standard for structural steel welding.

D1.1 offers two paths. The fast one is a prequalified WPS: follow the code’s recipes and you skip testing. The prequalified list includes SMAW, SAW, GMAW (except short-circuit), MCAW, and FCAW. Notably, GMAW-S, GTAW, ESW, and EGW are not prequalified. If you’re running short-circuit MIG on structural work, you need to qualify it yourself — the code doesn’t take it on faith (the reasoning behind that rule is worth reading).

Prequalified doesn’t mean anything goes, though. You still have to stay inside the code’s approved base metal groups, filler classifications, thickness ranges, and positions. Step outside those limits and the prequalification no longer covers you.

WPS, PQR, and Essential Variables

When a process isn’t prequalified, or a job demands proof, you produce two documents:

• WPS (Welding Procedure Specification) — the recipe the welder follows.
• PQR (Procedure Qualification Record) — the test evidence that the recipe works.

A PQR documents process, base metal, filler, shielding gas, preheat, heat input, and pass sequence. Any of these the code treats as an essential variable can’t change without a fresh PQR. Swap the gas, jump from spray to short-circuit transfer, switch filler classification, or change the process entirely, and you’re back to testing.

Two variables welders underestimate are preheat and interpass temperature. Preheat slows cooling and drives out hydrogen; interpass caps how hot the joint gets between passes. Both are written into the WPS for a reason — ignore them and a technically sound procedure can still yield a cracked, weak weld.

Matching vs. Undermatching Filler

Filler strength is its own battle. Most designs call for matching filler, where the electrode roughly equals the base metal strength. Sometimes undermatching filler is deliberately chosen to improve toughness or avoid cracking in thick, highly restrained joints. D1.1:2025 revised subclause 5.6.1 on matching and undermatching filler metal strength and reorganized the filler metal strength tables — a reminder that even “stronger” filler isn’t automatically the right call. Heat input ties into this too: run too hot and fast, or too cold and slow, and you change the weld’s microstructure and toughness. On the stick side, setting the machine correctly matters, and our 3/16 E7018 amperage guide walks through the dials a WPS often specifies.

Beyond Structural Steel: ASME and ISO

Structural steel is only one world. Pressure vessels, piping, and boilers fall under ASME Section IX, which governs both procedure qualification (the WPS/PQR pair) and performance qualification (each individual welder). Internationally, ISO 15614-1 plays the same role, qualifying procedures through documented welding procedure tests. The vocabulary and essential variables shift, but the principle is identical: qualify the procedure, then hold everyone to it. For a deeper look at how these standards translate to the shop floor, see the ANSI overview of the 2025 D1.1 update.

So when someone claims stick is “stronger” because it’s certified, ask to see the WPS. Any process — stick, MIG, flux-cored, or submerged arc — delivers guaranteed strength only when the paperwork matches the work. That’s the standard both sides are actually judged by.

Common Mistakes That Make Either Weld Weak (and How to Fix Them)

Here’s the uncomfortable truth: process choice almost never causes a failure. Operators do. The same mistakes sink stick, MIG, and flux-core welds alike, and most of them trace back to prep, heat, or cleaning. If you can spot the symptom, you can usually trace it to a fixable cause.

Cold lap and lack of fusion

A flawless-looking MIG bead can hide zero penetration — cold lap. The wire melts and sits on top of the base metal without bonding, so the joint looks perfect and fails under load. It usually comes from running too cold, moving too fast, or holding the wrong travel angle. The fix: bump voltage and wire speed to match thickness, slow your travel, and keep the gun angle pushing into the puddle. On the stick side, too little amperage and a long arc create the same weak toe; turn up the heat and shorten the arc. This same low-heat, slow-travel combination is what produces an overlap welding defect, where molten metal rolls over the toe without fusing.

Porosity

Gas pockets under the surface come from contamination, moisture, or shielding problems. MIG hates a breeze — even a shop fan or an open door can blow shielding gas away — while stick hates wet electrodes and dirty steel. Fix both the same way: grind to bright metal, remove oil, paint, and mill scale, run the right gas flow (typically 20–25 CFH), and block drafts. Never weld over rust and expect a sound bead.

Slag inclusions

Incomplete slag removal between multi-pass stick welds is the dominant source of slag-inclusion defects. Molten metal traps the previous pass’s slag, and that trapped layer becomes a crack starter. Chip, then wire-brush every single pass. MIG isn’t immune — spatter and silicon islands play the same role, so clean between layers here too.

Undercut

Undercut is a groove melted into the base metal along the weld toe and left unfilled. It’s a classic sign of excessive current or too much arc force. Dial the amperage back, snug the travel angle, and let the puddle fill the edges. Undercut concentrates stress and is a rejection item under AWS D1.1.

Hydrogen cracking

Low-hydrogen electrodes absorb moisture fast. Leave a 7018 out overnight and it can pick up enough hydrogen to crack a restrained, thick joint hours after you walk away. Store opened low-hydrogen electrodes in heated quivers at 80°C or above, and re-dry damp rods per the manufacturer’s spec. On MIG, use clean, dry wire and check for a frayed liner or worn contact tip — worn tips and mis-set drive-roll tension cause bird-nesting and arc instability that quietly ruins fusion.

Fit-up, gaps, and distortion

Poor fit-up forces you to bridge gaps with excess metal, which builds stress and invites cracking. Cut and grind parts to a consistent root gap, tack properly, and use balanced or backstep welding to manage heat. Excessive heat input pulls thin sections out of shape, so clamp, sequence, and let parts cool between passes.

Verify the basics first

Before blaming the metal or the process, confirm your machine polarity is set for the electrode and wire you’re running — reversed polarity alone changes penetration and bead shape. A few minutes of deliberate welding practice on scrap beats guessing on a real part every time.

How to Choose the Right Process: Practical Tips and Final Verdict

Here is the practical truth: the best process is the one that lets you lay down a defect-free, code-compliant weld in the environment where the work actually happens. Strength becomes secondary to whether the bead is sound in the first place.

Use Stick When…

• Thick material rules the job. Stick is rated for thicker plate on many machines, while a 110-volt MIG unit is often limited to about 3/16 inch on flux-core and 1/8 inch on gas.
• The steel is dirty, rusty, or painted. Stick arcs burn through mill scale and contaminants that would choke a MIG wire.
• You are outdoors or in wind. Shielded metal arc welding shrugs off breeze that would blow away MIG shielding gas.
• The joint is high-carbon-equivalent or highly restrained. This is where E7018 low-hydrogen electrodes are often required to resist cracking.
• You are doing field repair or emergency work. A buzz box and a box of rods travel anywhere.

Use MIG When…

• Material is thin and clean. MIG dials down beautifully on sheet and light plate.
• You need speed and volume. Continuous wire feed slashes production time on repetitive work.
• You are indoors with good gas shielding. Controlled shop conditions play to MIG’s strengths.
• You are welding non-ferrous metals. Aluminium and stainless benefit from MIG’s clean arc, though polarity choices matter a lot here.

Your Decision Checklist

1. How thick is the metal? The thicker it gets, the more stick earns its keep.
2. How clean and how windy is the site? Dirt and wind favor stick or flux-cored.
3. Does the job have a procedure? A qualified WPS overrides personal preference every time.
4. What does your machine actually deliver? Match the process to real amperage, not brochure claims.
5. What is your experience level? Weld the process you can run consistently.

Test Your Own Weld: The Coupon Bend Test

You do not need a lab to check fusion. Cut a test coupon, weld it to spec, then clamp it in a sturdy vise and hammer it over until it bends 180 degrees. A simple 180-degree coupon bend test in a vise is a practical field check for fusion and defect-free welds. If the weld metal tears with a clean, ductile curve, you are good. If it cracks, peels open, or shows lack of fusion along the edges, the process or technique needs work before you trust it on a real structure.

Set Yourself Up to Succeed

Process choice only matters if your workspace supports it. A safe, organized booth with proper ventilation, power, and lead routing makes any process more consistent. Our guide to planning and setting up a safe welding shop walks through the essentials. Beyond gear, the biggest strength upgrade is skill, and skill comes from deliberate repetition, as covered in our complete guide to welding practice.

The Final Verdict

So, is stick stronger than MIG? For strength alone on qualified joints, no. Neither process is inherently stronger. The welder, the procedure, and the prep decide the outcome. AWS D1.1 codifies this by qualifying the procedure, not the process name. A certified E7018 stick weld and a properly tuned MIG weld on the same joint can both pass the same destructive tests.

Stop arguing about the machine. Learn both processes, weld to a written procedure, and validate your work with a bend test now and then. That is how real strength gets built.

Frequently Asked Questions

Is stick welding actually stronger than MIG?

Not inherently. When both are run to code on clean steel, E7018 stick and ER70S-6 MIG wire both deliver about 70,000 psi minimum tensile strength, so the weld metal is equivalent. Stick only gains a practical edge on thick, dirty, or outdoor work where deeper penetration and flux shielding improve reliability.

Why do so many welders say stick is stronger?

Because stick is far more forgiving in bad conditions. Its flux cleans dirty metal and shields the arc from wind, so it reliably produces sound welds where MIG would suffer porosity or lack of fusion. That real-world reliability gets mistaken for inherent strength.

Is 7018 stronger than MIG wire?

No. E7018 stick electrodes and ER70S-6 MIG wire share the same AWS minimums: 70 ksi tensile and 58 ksi yield. The deposited weld metal is mechanically equivalent when both procedures are properly qualified and executed.

Which is stronger on thick steel, stick or MIG?

On 1/2-inch-and-up plate, stick with E7018 often produces more reliable full-penetration joints because of its deep digging arc and low-hydrogen crack resistance. MIG can match it with spray transfer, high current, and multiple passes, but it needs clean metal and careful setup.

Is MIG stronger than stick on thin metal?

Generally yes, in practice. MIG’s controlled heat input prevents burn-through and warping on 16-gauge to 1/4-inch material, producing more uniform, crack-resistant welds than stick, which tends to overheat thin sections.

Does one process penetrate deeper than the other?

Penetration depends on polarity, current, transfer mode, and joint prep, not the process name. Stick with E6010/E6011 digs deep, and MIG in spray transfer penetrates deeply too. Either can achieve full penetration with the right procedure.

Can a MIG weld look perfect but still be weak?

Yes. A common failure is cold lap or lack of fusion from running too cold or too fast, especially with short-circuit transfer on thicker steel. The bead looks flawless but has not fused to the sidewall and fails under load.

Do structural codes treat stick and MIG differently?

Both SMAW and GMAW (except short-circuit transfer) are prequalified processes under AWS D1.1, so both are accepted for structural steel when applied per a qualified WPS. However, GMAW-S must be qualified by testing and is generally limited to thin material under AWS D1.3.

Authoritative Sources & Further Reading

• https://www.twi-global.com/technical-knowledge/faqs/mig-vs-stick-welding
• https://www.aws.org/standards-and-publications/codes-and-standards/d1-1/
• https://pubs.aws.org/Download_PDFS/D1.1-D1.1M-2025WebPV.pdf
• https://www.nature.com/articles/s41598-025-20140-4
• https://pmc.ncbi.nlm.nih.gov/articles/PMC12534551/
• https://www.thefabricator.com/thewelder/article/arcwelding/short-circuit-mig-prequalification-in-aws-welding-codes
• https://blog.ansi.org/ansi/aws-d1-1-2025-structural-welding-code-steel/
• https://weldinganswers.com/how-to-write-aws-d1-1-prequalified-welding-procedure-specifications/
• https://www.osha.gov/welding-cutting-brazing
• https://www.iieta.org/journals/mmep/paper/10.18280/mmep.120715