Find Your Settings
MIG Settings Reference
| Material | Thickness | Wire Size | Voltage | WFS (IPM) | Transfer Mode | Gas |
|---|---|---|---|---|---|---|
| Mild Steel | 24 GA | .023"-.024" | 14-16V | 60-100 | Short circuit | 75/25 or C25 |
| 20 GA | .024"-.030" | 15-17V | 100-160 | Short circuit | 75/25 or C25 | |
| 16 GA | .030" | 16-18V | 150-220 | Short circuit | 75/25 or C25 | |
| 1/8" | .030"-.035" | 17-20V | 200-300 | Short circuit / globular | 75/25 or C25 | |
| 3/16" | .035" | 19-22V | 260-360 | Globular / spray | 75/25 or C25 | |
| 1/4" | .035"-.045" | 21-24V | 300-420 | Spray transfer | 90/10 or 92/8 Ar/CO2 | |
| 3/8" | .045" | 24-28V | 350-500 | Spray transfer | 90/10 or 92/8 Ar/CO2 | |
| 1/2" | .045" or larger | 26-30V | 400-550 | Spray transfer | 90/10 or 92/8 Ar/CO2 | |
| Stainless Steel | 24 GA | .023" | 14-16V | 80-130 | Short circuit | Tri-mix or stainless blend |
| 20 GA | .030" | 15-18V | 120-190 | Short circuit | Tri-mix or stainless blend | |
| 16 GA | .030" | 16-19V | 170-250 | Short circuit | Tri-mix or stainless blend | |
| 1/8" | .030"-.035" | 18-21V | 220-320 | Short circuit / spray | 98/2 Ar/CO2 or stainless blend | |
| 3/16" | .035" | 20-23V | 280-380 | Spray transfer | 98/2 Ar/CO2 or stainless blend | |
| 1/4" | .035"-.045" | 22-25V | 330-430 | Spray transfer | 98/2 Ar/CO2 or stainless blend | |
| 3/8" | .045" | 24-28V | 380-500 | Spray transfer | 98/2 Ar/CO2 or stainless blend | |
| 1/2" | .045" or larger | 26-30V | 430-560 | Spray transfer | 98/2 Ar/CO2 or stainless blend | |
| Aluminum | 24 GA | .030" | 15-17V | 90-150 | Pulsed / short-circuit-capable machines only | 100% Argon |
| 20 GA | .030"-.035" | 16-19V | 130-210 | Pulsed / short-circuit-capable machines only | 100% Argon | |
| 16 GA | .035" | 18-21V | 180-280 | Pulsed or spray | 100% Argon | |
| 1/8" | .035" | 21-24V | 250-380 | Spray transfer | 100% Argon | |
| 3/16" | .045" | 23-26V | 320-450 | Spray transfer | 100% Argon | |
| 1/4" | .045" | 24-27V | 380-500 | Spray transfer | 100% Argon | |
| 3/8" | .045" | 25-29V | 430-560 | Spray transfer | 100% Argon | |
| 1/2" | .045" or larger | 27-31V | 480-620 | Spray transfer | 100% Argon |
IPM: Inches Per Minute (wire feed speed). WFS: Wire Feed Speed. C25: 75% Argon + 25% CO2. Adjust settings 5-10V and ±20 IPM based on actual results and material condition.
Getting Your MIG Welder Dialed In
Voltage and Wire Speed Work Together
Voltage controls arc length and heat. More voltage = longer arc, hotter, wider bead. Less voltage = short arc, colder, tighter bead. Wire feed speed controls how much metal gets dumped in per minute. They work as a pair.
The balance is everything. Too much voltage and not enough speed? Wide, flat bead with no penetration. Flip it — not enough voltage and too much speed? Bumpy bead and porosity. You're chasing the sweet spot where the puddle sits right.
Short Circuit vs Spray: Two Different Beasts
Short circuit mode: Wire touches the puddle, creates a short, breaks apart, repeats. Lower voltage (often in the mid-teens to low-20s), moderate wire speed. Works for thin stuff and out-of-position. Less heat, more control. Good for sheet metal. Expect minimal spatter.
Spray mode: Wire stays just above the puddle and the metal sprays across like a hose. Happens above 100V with higher wire speeds. Thicker material, flat positions only. Hotter, faster, deeper penetration. The transition point varies with wire diameter and gas — know where your machine switches over.
Gas: The Invisible Part of the Equation
75/25 Argon/CO2 is the standard mild steel gas. Smooth arc, good penetration, minimal spatter. Works for most fabrication. C25 is just a different name for the same thing.
Pure CO2? Cheaper. Penetrates deeper. Hotter arc. More spatter. If cost matters and you don't mind cleanup, CO2 works for heavy structural steel. Aluminum typically uses 100% Argon. Stainless usually calls for a stainless-specific blend such as tri-mix or argon with a small CO2/oxygen addition, not straight CO2 and not a blanket 100% Argon rule.
Gas flow: 20-25 CFH for most work. Too little and the puddle oxidizes (porosity). Too much wastes gas and gets turbulent. Set it right and walk away.
Wire: Match It to Your Material
ER70S-6 for mild steel. Silicon and manganese in the wire clean up oxides, you get smooth beads and good wetting. Standard stuff, works great with 75/25 gas. ER308L for stainless — the "L" means low carbon so you don't get sensitization issues. ER4043 for aluminum if you're learning (easier, better puddle control). ER5356 if the aluminum is structural or it's going in the ocean. Can't mix up wires and materials — wrong combo = brittle mess.
Wire Size vs Material Thickness
.030" wire handles everything from 24 gauge to 1/4". That's why it's everywhere. Going thinner than 24 gauge? .024" wire. Thicker than 1/4"? .035" or .045". Each size burns at different amperages and speeds. Pick the right one or you're fighting your machine all day.
Polarity: DC+ Only
MIG needs DC+ (reverse). That's it. Check your machine. Some newer ones detect it automatically. Older ones? Verify before striking.
When Things Go Wrong
Porosity: You're either starved for gas (check your flow rate, clean the nozzle, no drafts blowing your shield away), or your wire is wet, or the base metal is dirty. Check all three.
Spatter: Too hot and/or wire speed too fast relative to the arc. Drop voltage a notch or bump wire speed. If you're running CO2, consider switching to 75/25 — less spatter inherently.
No penetration: Not enough juice or you're moving too fast. Increase amps or slow down your travel. Thick material might need spray transfer instead of short circuit.
Burn-through: You're cooking thin metal. Lower voltage, lower wire speed, stay in short circuit mode, move faster, or use thinner wire.
Frequently Asked Questions
Start low. For .030" wire on mild steel, sheet metal is often in the mid-teens, 1/8" is commonly in the high teens to low 20s, and heavier sections move into the 20s. Get the arc going, then bump voltage up in small steps until the bead looks right and the arc stays stable. Material thickness, wire size, and machine output all shift the exact range.
Mild steel: 75/25 (Argon/CO2) is the common starting point. Stainless usually uses a stainless-specific blend such as tri-mix or argon with a small reactive-gas addition depending on the process and transfer mode. Aluminum typically uses 100% Argon. Straight CO2 is mainly for steel when cost matters more than cleanup. Flow rate is often around 20-25 CFH.
Too fast: bumpy bead, lots of spatter, arc gets squirely. Too slow: fat, flat bead with poor fusion. Adjust by 20 IPM increments and watch the puddle. You want smooth and uniform.
.030" for thin and medium (sheet to 1/4"). Better control, finer beads. .035" for thicker (3/16" and up). Penetrates deeper, deposits faster. Don't fight .035" on thin sheet — it'll burn through.
Short circuit mode, low voltage, conservative wire speed, and .023" or .024" wire are the usual starting point for thin steel. Use a 75/25 shielding-gas mix, move fast, and stitch or skip around to control heat. Multiple light passes beat one heavy pass. Practice on scrap first.
