MIG Wire Size and Settings Chart for Every Thickness
Complete MIG welding wire size guide with voltage and wire speed settings by material thickness — mild steel, flux-core, stainless, and aluminum reference charts.
Choosing the right MIG wire size and dialing in voltage and wire speed are the two things that determine whether your welds are solid or sloppy. This reference chart covers the most common wire types, sizes, and starting parameters for mild steel, stainless steel, and aluminum — organized by material thickness so you can look up what you need and start welding.
Wire Size Selection
The wire diameter you use depends primarily on material thickness and your machine's amperage range. Thinner wire runs at lower amperages and is better for thin material; thicker wire carries more current and deposits more metal per pass.
| Wire Diameter | Material Thickness Range | Amperage Range | Best For |
|---|---|---|---|
| 0.023 (0.6mm) | 24 ga – 16 ga | 30–90A | Very thin sheet metal, auto body panels |
| 0.030 (0.8mm) | 22 ga – 3/16 inch | 40–145A | Most common for light-duty home welding |
| 0.035 (0.9mm) | 18 ga – 1/4 inch | 50–180A | General purpose — most versatile size |
| 0.045 (1.2mm) | 3/16 – 1/2 inch | 75–250A | Heavier fabrication, production shops |
For most home-shop welders running machines in the 110V to 220V range (140–200A), 0.030-inch and 0.035-inch are the two wire sizes you will use. Stock both if your machine accepts them.
Mild Steel Settings (ER70S-6, C25 Gas)
ER70S-6 is the standard solid MIG wire for mild steel. The "S-6" designation means it contains higher levels of silicon and manganese for better wetting and deoxidation — making it forgiving on material that is not perfectly clean.
| Material Thickness | Wire Size | Voltage | Wire Speed (IPM) | Gas Flow (CFH) |
|---|---|---|---|---|
| 24 ga (0.024 in) | 0.023 | 15–16V | 100–150 | 15–20 |
| 22 ga (0.030 in) | 0.023–0.030 | 16–17V | 130–180 | 15–20 |
| 20 ga (0.036 in) | 0.030 | 17–18V | 150–200 | 20 |
| 18 ga (0.048 in) | 0.030 | 17.5–18.5V | 180–250 | 20 |
| 16 ga (0.060 in) | 0.030–0.035 | 18–19V | 200–300 | 20–25 |
| 14 ga (0.075 in) | 0.035 | 19–20V | 250–350 | 20–25 |
| 1/8 in (0.125 in) | 0.035 | 20–22V | 300–400 | 25 |
| 3/16 in (0.188 in) | 0.035 | 22–24V | 350–450 | 25 |
| 1/4 in (0.250 in) | 0.035–0.045 | 24–26V | 400–500 | 25–30 |
Flux-Core Settings (E71T-GS, No Gas)
| Material Thickness | Wire Size | Voltage | Wire Speed (IPM) | Notes |
|---|---|---|---|---|
| 18 ga (0.048 in) | 0.030 | 16–17V | 150–200 | Light touch — easy to burn through |
| 16 ga (0.060 in) | 0.030 | 17–18V | 180–250 | Good starting range |
| 14 ga (0.075 in) | 0.035 | 18–19.5V | 200–300 | Comfortable range for learning |
| 1/8 in (0.125 in) | 0.035 | 19–21V | 250–350 | Bread and butter flux-core territory |
| 3/16 in (0.188 in) | 0.035 | 21–23V | 300–400 | Multiple passes for good penetration |
| 1/4 in (0.250 in) | 0.035–0.045 | 23–25V | 350–450 | Multi-pass required |
Remember that flux-core runs on DCEN (electrode negative) polarity on most machines — the opposite of gas MIG. Verify your polarity before welding.
Stainless Steel Settings (ER308L, Tri-Mix or C2 Gas)
Stainless requires different wire and gas. Use ER308L wire for welding 304 stainless, ER316L for 316 stainless. The shielding gas is typically a tri-mix (90% helium, 7.5% argon, 2.5% CO2) or C2 (98% argon, 2% CO2). Run lower voltage and wire speed than mild steel at equivalent thickness — stainless retains heat more and warps easily.
Aluminum Settings (ER4043, 100% Argon)
MIG welding aluminum requires a spool gun or push-pull gun (the soft wire binds in a standard liner), 100% argon shielding gas, and ER4043 or ER5356 wire. Aluminum is more demanding to MIG weld than steel — consider TIG if you need precision on thin aluminum. For detailed aluminum guidance, see our aluminum welding guide.