ER70S-2 TIG Filler Rod: Settings & Application Guide
ER70S-2 Amperage by Diameter
| Diameter | Amperage Range |
|---|---|
| 1/16" (1.6 mm) | 40 - 90A |
| 3/32" (2.4 mm) | 80 - 150A |
| 1/8" (3.2 mm) | 120 - 220A |
ER70S-2 is the premium TIG filler rod for carbon steel. It has three deoxidizers (titanium, zirconium, and aluminum) on top of the standard manganese and silicon, which means it produces the cleanest, most porosity-free welds of any carbon steel filler. It is overkill for most shop work, but if you are TIG welding pipe root passes or doing work that has to be perfect, this is the rod.
What This Means in Practice
ER70S-2 is the premium TIG filler rod for carbon steel. Triple-deoxidized (silicon, manganese, and zirconium) for maximum weld purity. It produces the cleanest welds of any carbon steel filler but costs more than ER70S-6. Specify it for code work, X-ray quality joints, and any application where weld metallurgy matters more than cost per pound.
ER70S-2 Suitability Scores
How well this electrode matches common applications. Not a quality rating. all AWS-certified electrodes meet their specification.
When to Use ER70S-2
TIG welding of carbon steel pipe root passes where maximum weld quality is required.
Welding on slightly contaminated base metal where the extra deoxidizers help.
Critical applications where the highest quality filler rod is justified.
ER70S-2 Limitations
More expensive than ER70S-6 filler rod.
Deoxidizer content can affect weld chemistry in multi-pass applications.
Not commonly stocked.
ER70S-6 is more widely available and works fine for most non-critical TIG work.
ER70S-2 Storage Requirements
Store in clean, dry container. Avoid contact with oil, grease, or shop dust. Handle with clean gloves.
ER70S-2 Technical Specifications
| Property | Value |
|---|---|
| AWS Classification | ER70S-2 |
| Process | TIG Welding (GTAW) |
| Polarity | DCEN |
| Positions | flat, horizontal, vertical up, overhead |
| Penetration | medium |
| Coating Type | bare solid rod |
| 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-carbon steel, low-alloy steel |
| Shielding Gas | 100% Argon |
| AWS Specification | A5.18 |
ER70S-2 Questions
What TIG filler rod for carbon steel?
ER70S-2 for the highest quality welds, ER70S-6 for general purpose. ER70S-2 has three deoxidizers (titanium, zirconium, aluminum) that produce the cleanest welds with the least porosity, making it the standard for pipe root passes and X-ray quality work. ER70S-6 is more widely available and cheaper, and works fine for non-critical TIG welding. Both are 70,000 psi tensile strength. Use ER70S-2 when the weld has to be perfect, ER70S-6 when it has to be good. See also: ER70S-6 specifications.
Can ER70S-2 be used as MIG wire?
Yes, but it is not the ideal choice. ER70S-2 works as MIG wire but its triple deoxidizer system is optimized for TIG welding. For MIG, ER70S-6 is more practical because its higher manganese and silicon content handles surface contamination better at MIG welding speeds.
What makes ER70S-2 better for root passes?
The zirconium, titanium, and aluminum deoxidizers in ER70S-2 produce a very clean weld puddle with minimal porosity. This is critical for root passes on pipe where the back side of the weld cannot be inspected during welding and must pass X-ray.
Where to Buy ER70S-2
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External Resources
Manufacturer data sheets and standards for ER70S-2.
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.