ER70S-6 MIG Wire: Settings, Gas & Amperage Chart
ER70S-6 Amperage by Diameter
| Diameter | Amperage Range |
|---|---|
| 0.023" (0.6 mm) | 30 - 90A |
| 0.030" (0.8 mm) | 40 - 145A |
| 0.035" (0.9 mm) | 50 - 220A |
| 0.045" (1.2 mm) | 75 - 350A |
ER70S-6 is the default MIG wire. If you buy a spool of MIG wire at any welding supply store without specifying a type, this is what you get. The high silicon and manganese content lets it handle lightly rusted or oily steel better than other MIG wires, and it produces smooth beads with good wetting. It runs on DCEP with 75/25 argon/CO2 or 100% CO2 shielding gas.
What This Means in Practice
ER70S-6 is the wire you are already using if you own a MIG welder. It is the default spool shipped with most machines and the wire most shops stock. The higher silicon content (0.80-1.15%) gives it better wetting action and forgiveness on lightly contaminated steel compared to ER70S-3. The downside is a glassy silicon residue on multi-pass welds that can trap contaminants if not cleaned between passes.
ER70S-6 Suitability Scores
How well this electrode matches common applications. Not a quality rating. all AWS-certified electrodes meet their specification.
When to Use ER70S-6
General shop welding on mild steel.
Auto body and frame repair.
Anything from sheet metal to heavy plate.
Production and robotic welding.
The default MIG wire for most mild steel applications.
ER70S-6 Limitations
Needs shielding gas at all times.
Wind blows the gas away, so it is not great outdoors without wind screens.
Can leave silicon islands on the surface that need to be cleaned before painting.
Higher deoxidizer content than ER70S-3.
ER70S-6 Storage Requirements
Store in dry area. Protect spool from moisture and contamination. Replace if wire shows rust or discoloration.
ER70S-6 Technical Specifications
| Property | Value |
|---|---|
| AWS Classification | ER70S-6 |
| Process | MIG Welding (GMAW) |
| Polarity | DCEP |
| Positions | flat, horizontal, vertical up, overhead |
| Penetration | medium |
| Coating Type | copper-coated solid wire |
| Tensile Strength | 70,000 psi |
| Yield Strength | 58,000 psi |
| Elongation | 22% |
| Impact Toughness | 20 ft-lbs at -20°F |
| Base Metals | carbon steel, low-alloy steel |
| Shielding Gas | 75% Ar / 25% CO2 (most common), 100% CO2, 90% Ar / 10% CO2, 95% Ar / 5% CO2 |
| AWS Specification | A5.18 |
ER70S-6 Questions
What MIG wire for mild steel?
ER70S-6 is the default MIG wire for mild steel. It works on everything from sheet metal to heavy plate and handles lightly rusted or oily surfaces better than other carbon steel wires. Run it on DCEP with 75/25 argon/CO2 for the cleanest welds, or 100% CO2 for deeper penetration on thicker material. If your steel is very clean and you want less silicon residue on the bead, ER70S-3 is an alternative, but ER70S-6 is the right choice for 90% of mild steel MIG work. See also: ER70S-3 specifications, ER70S-3 vs ER70S-6 comparison.
What shielding gas for MIG welding steel?
75% argon / 25% CO2 (called 75/25 or C-25) for general purpose mild steel MIG welding. This mix gives a smooth arc, low spatter, and a clean bead appearance. Use 100% CO2 for deeper penetration on thicker material or when cost matters, but expect more spatter. Some shops use 90/10 argon/CO2 for thin or cosmetic work. Never use 100% argon on carbon steel, it causes poor wetting and an unstable arc (argon-only is for aluminum and stainless).
Can I MIG weld outdoors?
MIG welding requires shielding gas, and wind blows the gas away from the weld puddle. Even a 5 mph breeze can cause porosity. For outdoor work, you have three options: build a wind screen around the joint, switch to flux-core wire (E71T-11) that generates its own shielding, or switch to stick welding. If you must MIG outdoors, increase your gas flow rate slightly and work close to the puddle, but be aware that results will be inconsistent in any real wind. E71T-11 specifications, flux-core wire that needs no shielding gas, designed for outdoor and field work. See also: E71T-11 vs ER70S-6 comparison.
Where to Buy ER70S-6
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External Resources
Manufacturer data sheets and standards for ER70S-6.
Data sourced from AWS A5.18/A5.18M. Amperage ranges are approximate starting points. adjust based on position, fit-up, and material thickness. Always follow manufacturer recommendations and applicable codes.