MIG Welding Chart: Complete Voltage, Wire Speed & Gas Settings Guide

It’s every new welder’s frustration. After spending hours grinding and practicing, they lay their first bead only to watch it sputter, pop, or burn right through their material. More often than not, the culprit isn’t skill, it’s improper machine settings that could’ve been solved with the correct MIG welding chart.

1. Introduction: What is a MIG Welding Chart and Why it Matters

Start with the name, because it confuses plenty of newcomers. “MIG” is shop-floor shorthand for the process the American Welding Society (AWS) formally calls Gas Metal Arc Welding, or GMAW. The “metal” is the continuously fed wire acting as both electrode and filler metal. The “gas” is the shielding gas, usually argon, CO2, or a blend, that keeps air away from the molten pool. Wire feed, gas, arc length, and travel speed all have to cooperate, and the bead tells you immediately when one of them is off.

That cooperation is exactly what a MIG welding chart exists to help with. At its core, it is a reference table that lines up what you already know, base material, thickness, and wire diameter, against what you actually have to dial in: wire feed speed, voltage, resulting amperage, shielding gas, and travel speed. Many charts also list polarity and recommended stick-out.

Here is what a simple one looks like:

Material	Thickness	Wire	Gas	Wire Feed Speed	Voltage
Mild steel	1/16 in (1.6 mm)	.030 in	75/25	250–300 ipm	17–18 V
Mild steel	1/8 in (3.2 mm)	.030 in	75/25	300–350 ipm	18–19 V
Stainless	1/8 in (3.2 mm)	.030 in	98/2	200–250 ipm	16–18 V
Aluminum	1/8 in (3.2 mm)	.035 in	100% argon	280–330 ipm	19–20 V

Here is why this topic matters more than any other in GMAW. Improper parameters are among the leading causes of lack of fusion, burn through, and excessive spatter. Those three failures account for a huge share of the bad welds beginners bring home, and they are almost entirely settings problems rather than skill problems.

• Lack of fusion happens when amperage is too low, travel speed is too fast, or the work is cold and dirty. The puddle looks fine, but the bead never melted into the base metal. It peels off later, sometimes weeks later, which is the worst way to find out.
• Burn through is the opposite failure. Too much heat for the thickness, usually high wire feed speed combined with a fast or wide weave, and the puddle drops straight through instead of filling the joint.
• Excessive spatter shows up as orange popcorn along the sides of the bead. It points to a gas mix unsuited to the material, a wire feed speed and voltage combination out of balance, or a gun angle pushing the arc awkwardly.

Each of those is diagnosable, and each traces back to a number on a chart. That is the practical value of having one in front of you instead of guessing.

It is equally important to know what a chart cannot do for you. On code work, a chart is not a Welding Procedure Specification (WPS), and it does not replace procedure qualification or performance qualification testing. Structural and pressure work falls under codes such as AWS D1.1, which carry their own prequalification rules, essential variables, and documentation requirements. A shop chart you made at the bench is a great tuning aid and absolutely not a code document.

Not every job belongs on a MIG machine either. Thin, rusted, outdoor, or heat-distorted material often goes to stick, and the case for that process is laid out in why SMAW still wins for a lot of work. Likewise, some aluminum jobs are better handled with flux core than solid wire, which is covered in what actually works with aluminum flux core. Charts are one tool inside a larger toolkit.

What this guide covers

The rest of this guide follows the order you actually need. First, the core parameters and how they interact. Then detailed charts by material and thickness, including solid wire in .023, .030, .035, and .045 inch. After that, transfer modes, since a chart built for short-circuiting transfer will be wrong for spray and a single chart cannot cover both. Then gas, polarity, and wire selection, because changing the gas or flipping polarity invalidates the numbers on the page. From there, the mistakes that trip people up, a systematic troubleshooting method that links each defect back to a specific setting, the line between a shop chart and a code-ready WPS, and finally how to build your own tested chart for your machine, gas, and shop. If you are new to aluminum specifically, the complete aluminum MIG guide picks up the material-specific details in depth.

One last thing before we start. Charts never cover safety, and safety is not optional. Welding fume contains metals that can damage your lungs, and the hazards are documented in detail by NIOSH and OSHA. Ventilation, respirators, eye protection, and fire watch discipline come before the voltage knob every single time.

With that groundwork laid, let’s dig into the parameters a chart is actually telling you to change.

2. Understanding the Core MIG Welding Parameters

A MIG welding chart is only as good as your understanding of each number. Change one and the rest respond: the arc is a small controlled fire fed by current, arc length, travel speed, shielding gas and stick-out.

Voltage: the Arc Length and Bead Shape Control

Voltage is the electrical push that keeps the arc burning, and the primary control over arc length. Higher voltage stretches the arc, spreading heat wider, flattening the bead and raising penetration at the toes. Lower voltage shortens it, giving a smaller, rounder bead with deeper penetration and taller reinforcement, but risks stubbing the torch. If the bead looks like a road puddle, add voltage; a stack of dimes means less.

Voltage is not a free adjustment. On most MIG machines it is preset by the material program or trimmed with a separate knob, and modern power sources select it from wire feed speed via a synergic setting, while older constant-voltage machines set it directly. Either way, voltage and wire feed speed are linked.

Wire Feed Speed and Amperage: Where the Heat Comes From

Wire feed speed (WFS) is the number most often listed on a chart, in inches per minute (ipm) or meters per minute (m/min). It tells the feeder how much wire to push each minute, and on most constant-voltage MIG machines it directly correlates to amperage: more wire needs more current to melt it, so the arc gets hotter automatically. A chart reading “0.030 wire, 3/8 inch steel, WFS 250 ipm” points to roughly 90 to 110 amps depending on the unit and gas, and you rarely set amperage by hand on a CV MIG machine.

Wire diameter changes everything: feeding 250 ipm of 0.045 instead of 0.030 demands current the machine may not deliver, so the wire buckles or the torch sputters. The MIGATronic knowledge base and the AWS welding forum both discuss this across machine brands.

Amperage still matters directly: it sets molten pool size and penetration depth. Too little current and the wire melts slower than the feeder pushes it, giving a stubby, unpenetrated bead and heavy spatter. Too much and you get a wide, flat, burned-through puddle with no reinforcement.

Shielding Gas: The Invisible Half of the Weld

Gas does more than keep the atmosphere away: it shapes the arc, stabilizes the pool and affects the voltage the machine needs. That makes it the most common reason a chart “does not work” for someone else.

• 75% argon / 25% CO2 (C25): the mild steel default, with a stable, forgiving arc, good penetration and clean beads.
• 100% CO2: runs hotter and deeper, popular for thicker steel and heavy fabrication, but rougher beads and more spatter.
• 90% argon / 10% CO2: a “tri-mix-like” compromise for production, cleaner than pure CO2 with less spatter than C25.
• Argon blends for stainless (98% argon / 2% CO2) and pure argon for aluminum behave completely differently from steel mixes.

Change the gas and the chart numbers shift; the same wire and thickness can need a different WFS and voltage with C25 versus pure CO2. If you do not know which gas your chart assumed, you are guessing. Cylinder handling has real safety rules, so read the OSHA welding, cutting and brazing safety page first. For aluminum, argon is non-combustible while helium mixtures and hydrogen behave differently, as the complete aluminum MIG welding guide explains.

Travel Speed: The Forgotten Variable

Travel speed is how fast you move the torch along the joint, in inches per minute, and the parameter most often missing from a chart. Slow travel with high heat input gives a wide, flat, deeply penetrated bead and risks burn-through on thin material; fast travel spreads the same heat over more distance, producing a narrow, tall bead that may lack fusion. Heat input is amps multiplied by volts, divided by travel speed. Charts implicitly assume 8 to 12 ipm for hand welding thin and medium steel, so log your travel speed beside every setting you test.

Stick-Out: The Adjustment That Quietly Ruins Welds

Stick-out, or contact tip to work distance, is the wire protruding beyond the contact tip: typically 3/8 inch for steel and 1/2 to 5/8 inch for aluminum, depending on joint position, thickness and wire diameter. Stick-out greatly affects the heat input and voltage drop of a GMAW arc. A short stick-out concentrates the arc on the puddle, giving a tighter, more directed bead that typically needs lower voltage. A long stick-out lets the arc wander, adds resistance along the exposed wire, raises the voltage needed to sustain the arc, and risks the hot tip catching on the work, the classic stubbing and spatter signature.

Stick-out also changes shielding. The contact tip sprays gas in a cone, and a long wire throws its own shadow into it, so the pool edge gets less protection and more porosity, especially on aluminum where oxide film is unforgiving. Cleaning aluminum the right way before welding matters for the same reason.

How the Parameters Interact

Amperage comes from wire feed speed. Voltage is set by the machine but is partly a function of arc length, which you control with stick-out and torch angle. Travel speed and stick-out decide how much heat lands in one spot, and gas type sets which voltage and WFS range behave well.

Parameter	Primary control	Symptom when wrong
Wire feed speed	Amperage, heat input	Cold bead or stubbing
Voltage	Arc length, bead profile	Flat bead or heavy spatter
Travel speed	Bead width, heat per inch	Burn-through or lack of fusion
Stick-out	Arc direction, heat concentration	Wandering arc, stubbing, porosity
Shielding gas	Stability, spatter, penetration	Rough bead, porosity, erratic arc

When something looks wrong, resist changing three things at once. The CDC NIOSH welding health and safety resources and the AWS materials referenced in this guide reflect the same idea: welding quality is a system, not a single number. Change one parameter, make a coupon, and observe. That is how you read a chart instead of copying it.

3. MIG Welding Chart By Material, Thickness, and Wire Size

A MIG welding chart only works if its numbers match your job. Voltage, wire feed speed, and amperage all shift depending on material, thickness, and wire size. With that in mind, it’s best to start from the material you’ll most likely run: mild steel.

Mild Steel: The Shop Standard

For most fabrication, ER70S-6 solid wire, DCEP polarity, and a 75 percent argon / 25 percent CO2 blend is the go-to setup. The gas provides a stable arc with minimal spatter, while the filler is widely available and forgiving. Choosing the right wire diameter has the biggest impact here.

.023 inch wire is ideal for thin sheet metal, as its lower heat input helps prevent warping or burn through. .030 inch wire bridges the gap for lighter plate, while .035 inch wire is the most versatile size for anything from 16 gauge up to 1/4 inch. For heavy plate and high deposition passes, .045 inch wire is the one to reach for.

Material Thickness	Wire	Voltage	Wire Feed Speed	Approx. Amps	Shielding Gas
24 ga (0.025 in)	.023 in	17-18 V	250-300 ipm	170-200 A	75/25 Ar-CO2
20 ga (0.036 in)	.023 in	18-19 V	350-400 ipm	220-250 A	75/25 Ar-CO2
16 ga (0.060 in)	.030 in	17-18 V	300-350 ipm	250-280 A	75/25 Ar-CO2
1/8 in	.030 in	19-20 V	400-450 ipm	280-320 A	75/25 Ar-CO2
1/4 in	.035 in	19-20 V	400-500 ipm	350-400 A	75/25 Ar-CO2
3/8 in	.035 in	22-23 V	500-550 ipm	380-420 A	75/25 Ar-CO2
1/4 in	.045 in	21-22 V	400-450 ipm	350-400 A	75/25 Ar-CO2
1/2 in and up	.045 in	24-26 V	550-600 ipm	450-500 A	75/25 Ar-CO2

Stainless Steel

Stainless doesn’t require a massive jump in numbers, but gas and filler metal are far less forgiving. Most mild steel wire won’t cut it, as ER308L or ER308LSi is used in its place. Stainless also tends to run best at slightly lower parameters due to its tighter arc and different heat conduction.

• 16 to 20 gauge with .030 or .035 wire: 16-18 V, 250-320 ipm with 90/10 tri-mix or 98/2 argon-CO2.
• 1/8 inch with .035 wire: 18-19 V, 300-350 ipm with 90/10 tri-mix.
• 1/4 inch with .035 or .045 wire: 20-22 V, 400-480 ipm with 90/10 tri-mix.

The tri-mix of 90 percent argon, 8 percent CO2, and 2 percent hydrogen helps keep a bright, oxidation-free tie-in, which is ideal for food equipment, railings, and aluminum wheel repair style finish work. For exact classifications, refer to the American Welding Society standards such as AWS A5.18 and A5.20.

Aluminum: A Different Animal Entirely

Aluminum conducts heat roughly three times faster than steel, so it pulls heat away from the puddle rather than absorbing it. This means higher wire feed speeds at similar voltages, different equipment, and a completely different gun technique.

Material Thickness	Wire	Voltage	Wire Feed Speed	Approx. Amps	Shielding Gas
20-24 ga	.030 or .035 in	17-18 V	280-350 ipm	130-180 A	100% Argon
1/8 in	.035 in	18-19 V	400-450 ipm	200-250 A	100% Argon
1/4 in	.035 in	20-21 V	450-500 ipm	280-320 A	100% Argon
3/8 in and up	.045 in	23-25 V	550-600 ipm	350-400 A	100% Argon

• Push, don’t pull. Drive the puddle ahead of the arc to keep heat on the filler instead of the base metal.
• Use a spool gun. Soft aluminum wire is prone to birdnesting through a standard push feeder, making a spool gun far more reliable.
• Swap your hardware. A knurled aluminum contact tip, a dedicated aluminum drive liner, and a larger nozzle are needed for consistent feeding and shielding.
• Clean aggressively. Remove the oxide right before welding. For specific products and steps, see how to prep aluminum for welding.
• Mind the thickness. Plate over 1/4 inch often benefits from preheat to slow heat loss. For filler selection between ER4043 and ER5356, the complete aluminum MIG welding guide goes into more detail.

Making These Numbers Work on Your Machine

All of the charts above are starting points. Machines from Miller, Lincoln, or others will vary in voltage output and amperage response at a given wire feed speed. Always start with the chart in your machine’s manual, such as those found in the Miller welding knowledge hub or Lincoln Electric’s training library, and tune from there to fit your setup.

4. Transfer Modes and How They Change Your Chart

Two welders can set the same amperage and voltage from the same MIG welding chart and get completely different results. The difference is what happens at the wire tip, and that behavior is transfer mode, the biggest variable a chart has to account for. The American Welding Society defines these categories in AWS terms, and you’ll meet them in manuals, WPS documents, and guides like the Miller welding knowledge hub.

Short Circuit Transfer (GMAW-S)

Short circuit is the most common mode and the default on most MIG machines. The wire melts into a droplet that touches the workpiece, the contact spikes the current, and electromagnetic force pinches it off into the puddle dozens of times a second. Because the droplet transfers while the circuit is shorted, arc voltage and heat input stay low, so it suits thin to medium steel up to about 1/4 inch (6 mm) depending on wire size, and it is what you get when you turn the machine down for lighter gauge or a delicate part.

Positionability is the big advantage: the puddle is small and cool, heat stays where you put it, and you can run vertical and overhead without chasing it down a plate, which makes it the most used mode for out of position field work. The limits are real. Spatter comes from the droplet detaching at high velocity, the same mechanism that gives less penetration than spray at equal amperage and a rougher, more rippled bead.

Globular Transfer

Globular is the awkward middle ground. At higher amperage and voltage the droplet grows larger, detaches under gravity rather than being pinched off at the tip, and lands on the workpiece. That drop from greater height means more spatter, a rougher bead, and more heat than short circuit at the same amperage. It shows up on heavier material and higher amperage work, and with 75 percent argon and some flux core wire combinations. If the bead throws excessive spatter, check whether your settings land in the globular window, then drop the amperage back to short circuit or push it up to reach spray.

Spray Transfer

Spray is what you want for flat, clean, high deposition work on thicker material. At high amperage and voltage the droplet is mechanically ejected from the wire tip by the arc’s electromagnetic force rather than gravity, which happens when the droplet diameter is roughly equal to the wire diameter at specific combinations of current, wire diameter, and shielding gas. The result is a smooth, wide, almost flat bead with minimal spatter and deep penetration. Spray needs higher voltage and amperage than the other modes plus more argon, which is why chart-driven spray settings for steel typically call for 90 percent argon and 10 percent CO2 instead of the 75/25 blend used for short circuit work on thin material.

The limitation is heat. Spray runs hot and fast, it’s hard to control out of position, and on thin material you can burn through before the puddle even forms. Spray on aluminum also needs a steady gun and a clean, oxide-free surface, since aluminum’s oxide layer and high thermal conductivity make consistent spray harder than on steel. Our Aluminum MIG welding guide covers that prep and setup.

Pulsed GMAW

Pulsed GMAW is the modern answer to the gap between short circuit and spray. Instead of one steady current, a pulsing power source rapidly switches between a high peak current and a lower background current. The peak creates spray-type droplet transfer, the background current cools the puddle and controls the heat, and the machine cycles so fast that the arc looks continuous while average amperage stays low. The result is spray type transfer at lower average heat inputs: the bead appearance, penetration, and spatter control of spray, but with a much smaller, more controllable puddle. That is why pulsed MIG is preferred for stainless, aluminum, and thin gauge in many production shops, and why it handles out of position work on heavier plate.

The catch is hardware. Pulsed GMAW requires a pulsing capable power source. You cannot pulse a standard constant-current MIG machine, and in most cases you cannot mix a pulsed program with a standard torch, gun, or wire feeder. Machine, feeder, and consumables must be a matched system, which is why pulsed isn’t standard on many home-shop welders. On aluminum it is a step up, since it handles conductivity and heat sensitivity better than constant current spray, and some shops even pair pulsed with flux core wire, covered in aluminum flux core welding.

Why One Chart Can’t Cover Everything

Transfer Mode	Best Used For	Main Limitation
Short Circuit (GMAW-S)	Thin to medium steel, out of position	Less penetration, more spatter
Globular	Mid-range amps, heavier flux core work	Heavy spatter, unstable puddle
Spray	Flat position, thicker steel, stainless, aluminum	High heat, burn through, hard out of position
Pulsed GMAW	Thin stainless and aluminum, controlled heat	Needs pulsing machine, matched feeder

Two more variables shift the numbers on any chart. Shielding gas decides which transfer mode you can even reach, and polarity matters because DCEP and DCEN put the heat on different sides of the joint. Lincoln Electric’s process guides explain why a chart labeled “75/25 argon” behaves nothing like one labeled “90/10 argon” at identical amperage. So check the mode your chart assumes, the gas it is specified for, and the wire type and size. If any of those don’t match your machine and materials, the chart isn’t wrong. It is just answering a different question.

And whatever mode you are in, fume extraction and ventilation still apply. OSHA’s welding and cutting guidance and the CDC’s welding health resources make it clear the metal is only part of the exposure, and the gas and flux add to it. The next section covers shielding gas, polarity, and wire classifications in detail.

5. Shielding Gas, Polarity, and Wire Selection

Every number on a MIG welding chart is a snapshot of three variables: polarity, shielding gas, and wire. Change one and the chart stops being true. Two welders can pull identical numbers, weld the same mild steel, and end up with one clean bead and one spatter-fest mess. That difference is rarely skill.

Polarity: Why DCEP Rules Solid Wire MIG

For solid wire GMAW, DC electrode positive (DCEP) is standard on the vast majority of machines: torch positive, workpiece negative. DCEP pushes roughly two-thirds of the arc heat into the workpiece, giving you the penetration a MIG chart promises and the stable arc its wire feed and voltage tables assume.

Most machines default to DCEP, but not every gun is wired that way out of the box. A TIG torch may be set for DCEN, and swapped leads leave you wondering why yesterday’s chart gives no penetration. Check your manual’s gun configuration setting, then confirm polarity with Miller’s knowledge hub or Lincoln Electric.

Choosing a Shielding Gas Mixture

For short circuit GMAW on mild steel, 75% argon and 25% CO2 (75/25 or C25) is among the most widely used mixtures in the industry. It strikes easily, holds a short arc, keeps spatter manageable, and most printed mild steel MIG charts assume it. If a chart names no gas, C25 is the safest assumption.

Pure CO2 is cheaper and runs hot enough to push deeper penetration at lower wire feed speeds, but it throws more spatter and runs a harsher arc that leans toward globular transfer. Never use it on thin stainless or aluminum. It also chills regulators and hoses in cold weather, so cold jobs often revert to a blend. Knowing how to buy and handle shielding gas saves frustration.

Gas	Typical Use	Effect on Chart Values
75% Ar / 25% CO2	Mild steel, short circuit	Baseline for most steel charts; stable, moderate spatter
90/10 or 80/20 Ar/CO2	Stainless, heavier steel	Slightly hotter, wider arc, higher voltage
Pure CO2	Cost-driven mild steel	Higher voltage, spatterier, favors globular transfer
100% Argon	Aluminum, thin stainless	Higher voltage and flow rate needed
Ar/He/CO2 tri-mix	Aluminum spray transfer	More heat, helps weld thicker aluminum

For aluminum, pure argon is the standard and any CO2 is a bad idea. Argon also flows differently than CO2, so it needs more volume. Rule of thumb: 20 to 30 CFH for steel with a blend, and 30 to 40 CFH for 100% argon on aluminum. Too little gas gives oxidation and porosity; too much creates a turbulent arc.

Solid Wire Classifications and Sizes

Most steel shops run ER70S-6 in .030 or .035 for general fabrication for its ductility and all-position capability, or ER70S-8 in .035 and .045 for higher strength and impact toughness. Stainless uses ER308L for common 304 and 316 work and ER316L where corrosion resistance matters more. Aluminum splits between ER4043 (silicon, more fluid, easier to weld) and ER5356 (stronger, for higher stress joints). These come from the American Welding Society, and code work requires the classification in the procedure.

Diameter changes machine settings too. A .045 wire needs a bigger contact tip and more gun power than a .030, which is why charts are split by size. Aluminum adds another constraint: wire and contact tips must be aluminum compatible, because aluminum oxide builds up fast and will destroy a copper or zinc-plated tip meant for steel.

Flux Cored Wire Changes the Rules

Switch to flux cored wire and you are on a different chart. Gas-shielded flux cored (FCAW-G, classifications like E71T-1C) and self-shielded flux cored (FCAW-S, like E71T-11) burn, transfer, and throw spatter differently than solid wire. Stick out changes too, typically closer to an inch for gas-shielded flux core versus 3/8 to 1/2 inch for solid wire. Voltage and wire feed relationships shift, so a solid wire chart cannot be reused safely.

Aluminum flux cored is its own specialty with its own clean-up and feeding quirks. If that is your application, read the complete aluminum MIG welding guide first, then compare it against what actually works with aluminum flux core welding.

How These Choices Shift Your Numbers

• Blended gas to pure CO2: raise voltage to hold arc length, expect more spatter, and re-check amperage because wire feed speed delivers different heat in each gas.
• Steel to aluminum: move to pure argon, bump amperage at the same wire feed speed, expect higher voltage, and use shorter stickout with aluminum compatible contact tips.
• Solid wire to flux core: reset voltage, re-learn stickout, expect a different bead profile and slag behavior.
• Correct polarity to reversed: heat distribution changes, penetration drops, and the chart becomes meaningless.

6. Common Mistakes When Using a MIG Welding Chart

A MIG welding chart is meant to be a starting point, not an exact script for every weld you will ever run. While the numbers provided can save a massive amount of guesswork, treating them as gospel is one of the quickest ways to get sputtering, lack of fusion, or burn through. More often than not, the chart isn’t wrong, it’s the way it’s being used that is.

Blindly Following The Numbers

One of the biggest traps for welders of any experience level is copying down a setting straight from a chart and striking an arc without testing it first. The truth is, every welding machine has slight variations, causing identical settings to perform differently from one power source to another. Two identical models can have slightly different calibrations, and older machines can drift even more over the years.

Even resources from the Miller Welds Knowledge Hub will preach the same ideology: a chart is for range finding, not for replacement of a test bead. If you want consistency, you must treat the chart as your launchpad before you ever commit to your final joint.

Ignoring Stick Out

Contact tip to work distance, better known as stick out, is criminally overlooked. Excessively long stick out is one of the most overlooked mistakes that causes voltage drop and erratic arc behavior. The longer the wire has to travel past the tip, the more resistance it builds up, causing your actual arc voltage to be far lower than what your machine is displaying.

For most solid wire MIG applications, keeping a stick out between 3/8″ and 1/2″ is the safe zone. Going past that, even by a quarter of an inch, can completely throw off the balance that your chart was based off of. Consistency with your hand is just as important as consistency with your dials.

Welding Over Dirty Material

No amount of perfectly dialed voltage and wire feed speed can make up for contaminated base metal. Mill scale, rust, oil, and paint drastically increase the difficulty of achieving proper fusion despite perfect chart numbers. All of these contaminants can introduce porosity, inconsistent penetration, or cause your puddle to behave wildly out of nowhere.

This becomes tenfold more important with reactive metals. For example, those getting into non-ferrous work should take the time to learn the proper methods found within Aluminum MIG Welding: The Complete Practical Guide, as well as utilizing the correct steps from Aluminum Cleaner for Welding: How to Prep Aluminum Right. A wire brush and degreaser may not seem glamorous, but they will save you more headaches than any fine adjustment ever could.

Incorrect Gas, Wire, or Setup Choices

Many welders will pull a mild steel chart and run it with the wrong shielding gas without even realizing it. Gas selection, wire classification, and polarity all change the arc characteristics tremendously. Using 100% CO2 where a mix is intended, or vise versa, will drastically shift the optimal voltage and wire feed speed for that exact transfer mode.

On top of this, using the incorrect consumables for your joint can create issues that no chart can remedy. It’s always worth double checking your filler selection against your base metal. Organizations such as AWS have classification systems in place for a reason, so referencing them can prevent you from mismatching your wire to the job at hand.

Not Tuning For Your Specific Machine

Lastly, the most humbling mistake of all is refusing to tune. Your shop, your cables, your ground clamp placement, your tip condition, and even your inlet gas flow all play a role in your arc. A brand new chart may be technically correct for the conditions it was tested in, but your conditions will almost always differ slightly.

At the end of the day, the fix for every one of these mistakes is the same: test, inspect, and adjust. Run a scrap coupon, observe your puddle, check your bead profile, and tweak in small increments from your chart’s range. A little discipline on scrap will always be cheaper than grinding out a bad weld on your final piece. Treat your MIG welding chart as advice, and your test weld as the final word. That is the difference between simply running wire, and welding with precision.

7. Troubleshooting Using Your MIG Welding Chart

Even the most accurate MIG welding chart is only a starting point. No two machines run exactly the same, so the true skill is knowing how to read a bad bead and correct it without guessing. The most reliable way to do this is by using a systematic approach: inspect the weld, rule out preparation issues, and adjust only one chart parameter at a time until the bead cleans up.

Establish a Troubleshooting Process

Before touching your voltage or wire feed speed, take care of the basics. Dirty metal, loose gun connections, or a kinked liner can all throw your settings off. For any job, confirm joint fit up, ground clamp placement, and stick out first. With that out of the way, use your chart to compare your current settings to the correct range for your material, thickness, and wire size. From there, any change can be traced back to the chart instead of chasing multiple variables at once.

Common MIG Weld Defects and Chart Corrections

Every defect tells a story. Knowing which parameter to blame is what saves time and prevents further damage to your work piece. The table below covers the most frequent issues you will run into while dialing in your settings:

Symptom	Likely Cause	Chart Based Adjustment	Practical Notes
Burn Through	Too much heat on thin material.	Decrease voltage, decrease wire feed speed, or increase travel speed.	Most common on sheet metal. Drop down to the lowest range your chart gives for that thickness before going below it.
Lack of Fusion	Insufficient heat input, poor joint preparation, or improper travel speed.	Slightly increase voltage or wire feed speed, and slow your travel speed to allow penetration.	Listen for a crisp, steady crackle. A cold looking toe with no tie in is the clearest giveaway.
Porosity	Inadequate shielding gas coverage, gas leaks, or contaminated base material.	Verify gas flow to the chart recommended range for your process, while correcting prep and fittings.	For reactive metals such as aluminum, utilizing a quality aluminum cleaner for welding is just as vital as your voltage settings. This is especially true for projects covered under an aluminum MIG welding process.
Excessive Spatter	Settings too hot for short circuit transfer, incorrect stick out, or gas imbalance.	Tune down voltage slightly, verify wire feed speed against the chart, and confirm your shielding gas matches the wire.	Double check your welding gas supply for restrictions. Consistent flow prevents spatter far better than overcorrecting amperage.
Cold Lap	Weld metal rolling over the base metal without tying in.	Increase heat input by raising voltage or wire feed speed within chart range, and direct the arc into the leading edge of the puddle.	Pay extra attention to tight joints. A slight change in torch angle will do more here than a drastic setting jump.
Ropey Beads	Travel speed too slow, excess heat input, or poor puddle control.	Increase travel speed, and if still excessive, drop voltage slightly while staying within your chart’s starting range.	Ropey beads may look thick, however they often lack proper fusion despite their appearance. Always verify tie in, not just bead width.

Troubleshoot With Safety in Mind

Any adjustments made while welding must be done with protection in mind. Fumes, intense arc radiation, and electrical hazards are all part of the process. For safe work practices, it is always worth referencing the guidance from OSHA’s welding, cutting, and brazing standards, as well as the practical information found within the Miller Welds knowledge hub, the Lincoln Electric resources, and AWS publications. These resources reinforce the same lesson that applies here: safety comes before chasing perfection.

Keep it Methodical

The key to troubleshooting is restraint. Change only one variable, make a small test bead, inspect it, and compare it back to your MIG welding chart before making the next change. If a defect persists after correcting prep, gas, and your chart based parameters, it may be a sign that you are outside of the transfer mode that your machine and chart are intended for, which should be handled with extreme care. Treat your chart as a map, not a guarantee. With patience and a methodical approach, bad beads will become your fastest teacher.

8. MIG Welding Charts, Codes, and Qualified Procedures

At some point the shop chart taped to the machine stops being enough. A structural job with an inspector walking the floor, a pressure vessel, a trailer hitch for a paying customer, a component shipping with a spec sheet. The numbers you have dialed in by feel now need paperwork behind them, and that paperwork has its own language.

The difference between hobby work and professional work is simple: a general purpose MIG welding chart and a Welding Procedure Specification (WPS) are different documents with different jobs. One is guidance. The other is a contract.

The General Purpose MIG Welding Chart: Reference, Not Authority

The charts we’ve walked through, voltage, wire speed, and gas ranges organized by material and thickness, are starting points. Manufacturers such as Miller and Lincoln Electric publish them as recommendations, and experienced welders treat them that way. They get you into the neighborhood of a good weld before you fine-tune by ear and eye. That is plenty for fences, gates, brackets, and farm repairs, where the only reviewer is you or a customer who trusts your eye. The moment a weld falls under a contract, a code, or an engineered design, a chart cannot accept liability, cannot be handed to an inspector, and is not a procedure.

What a Welding Procedure Specification (WPS) Actually Is

A WPS is a written, controlled document specifying every essential variable for a given weld: process, transfer mode, base metal specification and thickness range, filler metal classification, shielding gas composition and flow rate, polarity, current and voltage ranges, travel speed, preheat and interpass temperatures, and joint design. It is a recipe already verified to produce welds with acceptable mechanical properties.

Supporting it is a Procedure Qualification Record (PQR). A test coupon is welded exactly to the proposed procedure, then tested, typically with bend and tensile tests, sometimes impact or hardness testing depending on the code. Pass and the procedure is qualified; fail and it gets revised, then the cycle repeats. A WPS is valid because a physical coupon proved those variables produce sound welds. The paperwork is just the receipt.

Why Transfer Mode, Gas, Wire, and Base Metal All Matter

Codes classify certain variables as essential. Change one and a previously qualified procedure may no longer apply. For GMAW, the usual suspects:

• Transfer mode — short circuit, globular, spray, or pulsed. Short circuit to spray changes heat input and penetration.
• Shielding gas — moving from 75/25 argon-CO2 to 90/10 or a tri-mix can change transfer behavior and mechanical properties enough to invalidate a procedure.
• Filler metal — going from ER70S-6 to ER70S-3, or changing wire diameter beyond the qualified range, is an essential change.
• Base metal — specification, grade, and thickness range all count. Welding 3/8-inch plate under a procedure qualified for 1/4-inch is not automatically covered.

Charts group variables loosely. Codes treat them as individually critical. The American Welding Society maintains the standards defining these essential variables, and inspectors reference them when they question your setup.

Prequalified Procedures and AWS D1.1

Not every code weld requires your own qualification testing. AWS D1.1, the Structural Welding Code — Steel allows certain procedures to be used without individual qualification testing when they fall inside specific prequalified ranges. They are the code’s own pre-tested recipes.

To use one, stay inside D1.1’s boundaries. Process, transfer mode, base metal, filler metal, shielding gas, thickness range, and joint details must match the prequalified limits. Step outside any limit and you need a qualified WPS and PQR.

D1.1 treats short circuit transfer with caution, and its GMAW prequalification allowances are narrower than for SMAW or FCAW-G. On structural steel, the transfer mode you choose can decide whether you can lean on prequalification at all. A chart will never warn you about that.

When a Chart Is Not Enough: Recognizing Code Work

1. A specification or contract names a code — AWS D1.1, ASME Section IX, API 1104, or a customer’s own standard.
2. An inspector or third-party verification is involved — if someone will witness or test your work, documented procedures are coming.
3. The weld is structural, pressure-retaining, or safety-critical — bridges, buildings, pressure vessels, lifting equipment.
4. Traceability is required — filler lots, gas certificates, and welder qualifications must be recorded.

Spot any of these and get the governing WPS before you strike an arc. The chart can stay on the wall as a tuning reference, but it cannot replace the procedure you were handed. Unsure whether a job requires qualification? Ask before welding, never after.

Where Charts Still Earn Their Keep

None of this makes charts useless professionally. A good chart speeds up setup, gives apprentices a disciplined starting point, and cuts the guesswork that eats production time. A chart gets you close. A qualified procedure governs when the stakes demand it.

Codes exist because welds fail in ways that hurt people, and qualification systems exist to prevent that. Respecting the line between a chart and a WPS is not bureaucracy. It is professional responsibility.

9. Practical Tips to Build and Tune Your Own MIG Welding Chart

Published charts are a starting point, and a good one. But the most accurate MIG welding chart for any shop is the one you have tested on the exact power source in front of you. Two welders can run the same published settings on two different machines and get two very different beads. Pulse-capable sync machines, plain constant-voltage boxes, and multi-program units respond differently to the same wire speed and voltage numbers. Add spool take-up feel, feed roller tension, torch liner length, and shop temperature, and it becomes obvious why a printed chart felt wrong.

Building your own is not complicated. It is systematic, and once it exists it saves hours of guessing.

Step 1: Record the Setup Before You Spark the Torch

Before a single bead, write down the variables you control. A simple card or spreadsheet column is enough. Without this record you cannot repeat a good weld next week, and you certainly cannot hand the settings to another welder.

• Machine model and power source type (CV, pulse, multi-program)
• Wire type, diameter, and manufacturer
• Shielding gas and mixture, plus cylinder pressure and flow rate
• Polarity (DCEP for most solid wire MIG) and torch lead length
• Contact tip size, stick-out, and gas nozzle

Gas deserves its own attention. A shop running 75/25 versus one running 92/5 argon with a different wire will need different voltage and flow to land on the same bead. For the hardware side of flow rates and cylinder handling, the Airgas welding supplies buyer’s guide is useful, and Miller’s knowledge hub carries machine-specific setup material for most power sources you will meet.

Step 2: Run Test Coupons on Real Scrap

Test on the same alloy and thickness you weld in production, not on convenient mild steel. Alloys differ in thermal conductivity, melting behavior, and oxide films, so a coupon that welds beautifully in 304 stainless tells you little about aluminum. For aluminum, follow the prep and machine recommendations in the complete practical guide to aluminum MIG welding, and clean every coupon first as outlined in how to prep aluminum for welding.

Keep coupons small, cheap, and repeatable. A 4-inch by 1-inch plate with a 3-inch bead gives you room to judge tie-in and inspect the bead face without wasting stock.

Step 3: Judge the Bead, Not the Number

Here is the part most people skip. Inspecting a practice bead for tie-in, wetting, profile, and penetration is more reliable than chasing a perfect number. A chart tells you what to try. The bead tells you what you got.

• Tie-in: The bead start should blend into the previous one with no cold crater, no overlapping lump, and no visible restart porosity.
• Wetting: Good wetting shows a flat, slightly shiny bead spreading into the base metal. A tall, rounded, balled-up bead with a sharp toe means too little voltage or too much travel speed for the amperage.
• Profile: A MIG fillet should be flat to slightly convex with tight toe and cap edges. A rippled or ropey profile points to travel speed too slow for the amperage.
• Penetration: Judge it on a cut coupon, not by eye. A burned-through bottom edge on 16 gauge or a shallow root on 1/4-inch plate are both visible failures.
• Spatter and porosity: Heavy spatter usually means voltage or gas flow too low. Black pepper-like porosity means gas flow too high, contaminated gas, or dirty material.

Change one variable at a time. Move wire speed or voltage by small increments, then re-weld. Change two things at once and you cannot attribute the result, leaving you with a chart full of numbers that mean nothing.

Step 4: Tune Heat Input, Not Just Amps

Heat input depends on amperage, voltage, and travel speed together. A quick estimate in kJ/inch is:

Heat input = (Amps × Volts × 0.06) ÷ Travel speed in inches per minute

For example, 250 amps at 20 volts moved at 10 ipm gives roughly 30 kJ/inch, before arc efficiency, which for MIG typically falls in the 0.6 to 0.8 range. On thin material that number will distort the plate. On thick material it will soak it and cause undercut at the toes. If you work to a code such as AWS D1.1, minimum and maximum heat input limits are not optional, and the generic AWS framework is where you confirm them.

Step 5: Document, Then Re-Test When Conditions Change

Write the winning settings onto a card, a shop wall chart, or a shared spreadsheet. Include wire speed in your machine’s own units (in/min or m/min) plus measured amps and volts, because wire speed is only useful when tied to the machine that produced it. Then re-test whenever something changes: a new wire spool, a different gas cylinder, a new tip or nozzle, seasonal temperature swings, or a machine repair.

Safety Never Waits for a Good Chart

Tuning means running a lot of hot, spattering arcs on scrap. Respect the fundamentals every time: adequate fume extraction and respiratory protection, correct PPE, secured cylinders, and clear screens. Welding fumes and gases are a documented occupational hazard, and the guidance from OSHA on welding, cutting, and brazing and from NIOSH on welding hazards is worth reading once properly rather than skimming each time.

One last thing. When a setting refuses to cooperate, post the details on the AWS forum or a manufacturer support line such as Migatronic. Experienced welders can often spot a blocked liner, a mismatched contact tip, or a polarity mistake from a symptom description faster than you can test for it, saving you an afternoon of coupon welding.

10. Conclusion: Using MIG Welding Charts With Skill and Precision

A MIG welding chart is one of the most useful tools a welder can have, but its value is directly tied to how it’s used. After going over voltage, wire feed speed, amperage, transfer modes, shielding gas, polarity, material-specific charts, common mistakes, troubleshooting, and the difference between a reference chart and a qualified procedure, one truth remains: a chart eliminates guesswork, but it cannot eliminate the need for skill.

A Chart Is a Starting Point, Not a Finish Line

The sole purpose of a chart is to shorten the gap between uncertainty and a reasonable first try. By providing a proven range for a specific material, thickness, wire diameter, gas, and position, it saves hours of blind trial and error. However, no chart can account for every variable. A change in wire brand, shielding gas blend, machine calibration, joint fit-up, stick-out, travel speed, or even shop temperature can all shift the ideal settings for your setup.

Even the most precise numbers will fall flat without proper technique. Contaminants like rust, mill scale, or oil, poor joint prep, or an ill-fitting gap can all ruin a weld regardless of your settings. Factors such as work angle, torch manipulation, bead placement, and consistent travel speed play just as big of a role as voltage or wire feed speed, yet none of them are printed onto a chart.

Safety Comes Before Settings

With any welding process, safety is non-negotiable. The chart will never override the need for proper protection or hazard awareness. Before striking an arc, it’s imperative to review safe working practices to mitigate risks.

The OSHA welding, cutting, and brazing safety resources cover the essentials: correct eye protection and shade lens, flame-resistant clothing, ventilation and fume extraction, safe cylinder and regulator handling, correct electrode and work lead connections, hot work permitting, and fire watch procedures where required. The CDC/NIOSH welding resources go deeper into fume exposure, ventilation requirements, and the health risks of welding fume, which is classified as a known human carcinogen. Equipment-specific precautions are covered by Miller’s knowledge hub and Lincoln Electric, while the Migatronic technical library is a solid reference for European-standard machine behavior and safety conventions.

The practical point is simple. Before you touch a torch, check your hood lens, clear the area, confirm extraction, verify your ground clamp, and make sure nobody is working on the other side of that plate. Settings come after that.

Methodical Testing With Scrap Is the Real Bridge

Methodical testing with scrap material is always the bridge between a chart’s starting numbers and a perfect bead. It is the habit that separates welders who can dial in good settings on any machine from those who can only repeat what happened to work once on a particular day.

Start with the chart’s recommended range, then adjust in small, single-variable steps:

• Change one thing at a time. If you adjust voltage and wire feed speed together, you have no idea which one helped or hurt.
• Keep your travel speed honest. Constant, deliberate movement is what makes test beads comparable.
• Use coupons you can afford to ruin. Offcuts of the same material and thickness as the real job work best.
• Inspect the bead, don’t just look at it. Cut it open. Check for fusion at the root, look for porosity in the cross section, and look for undercut.
• Write it down. Machine, wire, gas, settings, and result. This is how a personal chart gets built, one verified line at a time.

Aluminum demands even more preparation discipline. If you are new to it, our guides on cleaning aluminum for welding and aluminum MIG welding technique explain why oxide layers and contamination cause more failed beads than mistyped voltages. And if your application uses flux cored wire rather than solid MIG wire, the aluminum flux core welding guide covers a different set of rules entirely, including self-shielded wire that needs no gas bottle at all.

Charts and Code Work

One final distinction is worth carrying forward. A general reference chart and a qualified procedure are entirely different documents. A chart tells you what usually works. A Welding Procedure Specification tells you what was qualified under the guidance of the American Welding Society, and it is the only acceptable basis for code work and pressure applications. Prequalified procedures within AWS D1.1 and similar codes carry specific limits on joint configuration, filler metal, position, and heat input. When the code calls for a WPS, a chart is not a substitute. The AWS technical forum is a reasonable place to work through interpretation questions, and AWS publishes the underlying standards.

Build the Habit

Charts will get you close. The remaining gap is closed by preparation, technique, and the willingness to test methodically. Make it a routine: pull the chart, run a test bead, cut it open, change one variable, and repeat. Keep a personal log of settings that work for your machine, your wire, your gas, and your shop.

That log becomes your own chart. It will be more accurate than any printed page because it was verified on your equipment, in your conditions, by your hands. That is where consistency, quality, and confidence in MIG welding actually come from.

Frequently Asked Questions

What is a MIG welding chart used for?

A MIG welding chart is used as a starting point to dial in voltage, wire feed speed, and gas for a specific material, thickness, and wire size. It helps eliminate guesswork, however it still requires tuning based off of your individual machine.

Is a MIG welding chart exact for every welder?

No, they are not exact for every machine. Each power source outputs slightly differently, so charts should always be used as starting ranges before fine tuning on scrap material.

What gas should I use for my MIG welding chart settings?

For solid wire on mild steel, a 75% Argon / 25% CO2 mixture is the most common for short circuit transfer. Aluminum requires 100% Argon, and some applications may utilize pure CO2 depending on the wire and desired results.

Do I need a different chart for flux core welding?

Yes. Flux cored wires often run on different parameters, can be self shielded or gas shielded, and generally require different voltage and wire feed speeds compared to solid GMAW wire. Always use a chart specific to your flux core wire.

What is the difference between a shop chart and an AWS WPS?

A shop chart is a general guideline for practice and production, while an AWS Welding Procedure Specification (WPS) is a qualified, documented procedure used to meet code requirements. For structural or contract work, the qualified WPS is what must be followed.

Why am I burning through even with the chart settings?

Burn through is most common on thin sheet metal. This can be caused by being too slow with travel speed, using too high of voltage or wire feed speed, excessive stick out, or not utilizing the correct transfer mode. Try faster travel speed or stepping down your parameters.

Should I use short circuit or spray transfer for thicker steel?

For thicker steel, spray transfer is oftentimes more efficient and provides better fusion, however it requires more voltage, amperage, and typically a higher argon gas mixture. Short circuit transfer is still utilized, but may require multiple passes or be limited by thickness capabilities.

How do I know if my settings are correct after using a chart?

Check for proper tie in at the toes of the weld, a consistent bead profile, minimal spatter, no excessive porosity, and no signs of burn through or lack of fusion. If possible, inspect your test coupon and adjust in small increments until these qualities are achieved.

Can I use the same MIG welding chart for aluminum?

Not reliably. Aluminum requires a different wire type (usually 4043 or 5356), a spool gun or push-pull system in many cases, 100% Argon shielding gas, and drastically different parameters. It is much more sensitive to heat input than mild steel.

Is wire feed speed or voltage more important to adjust first?

It depends on the issue. If your arc is too long and spattery, voltage is often the culprit. If your amperage is too low causing cold lap, wire feed speed is usually the parameter to adjust first, as it directly controls amperage on a constant voltage machine.