ER80S-D2 High-Strength MIG Wire for Structural Steel
80,000 psi MIG wire with molybdenum for welding high-strength low-alloy (HSLA) steels and 1/2Cr-1/2Mo piping. Runs 50 to 350 amps on DCEP, rated for flat, horizontal, vertical up, overhead. Amperage chart by diameter below.
ER80S-D2 is a solid MIG wire classified under AWS A5.28 for welding high-strength low-alloy (HSLA) steels. It deposits weld metal with approximately 80,000 psi tensile strength, making it a strength match for HSLA base metals with yield strengths up to approximately 65 ksi such as ASTM A572 Gr.50-65 and A588. Some codes permit ER80S-D2 as an intentional undermatch filler on higher-strength steels like A514/A517 for specific joint types (e.g., AWS D1.1 Table 4.3 for fillet and PJP welds), but it does not produce a strength-matched weld on those 100 ksi yield steels. The wire contains approximately 0.5% molybdenum and higher manganese than ER70S-6, which provide the increased strength and improved low-temperature toughness. ER80S-D2 is also used for welding 1/2Cr-1/2Mo (P1 group) piping. For higher chrome-moly grades, different fillers are required: ER80S-B2 for P11 (1-1/4Cr-1/2Mo) and ER90S-B3 for P22 (2-1/4Cr-1Mo). For MIG welding, use with 75/25 Ar/CO2 or 90/10 Ar/CO2 shielding gas. For TIG, use 100% argon. Preheat and interpass temperature requirements follow the base metal specification.
What This Means in Practice
ER80S-D2 is a step up from ER70S-6 when you need stronger weld metal. The 80 in the name means 80,000 psi tensile strength (vs 70,000 for ER70S-6). It contains approximately 0.5% molybdenum which improves strength and toughness. Use it when the base metal is stronger than standard A36 and the weld needs to match.
What Amps for ER80S-D2?
| Diameter | Amperage Range |
|---|---|
| 0.030" (0.8 mm) | 50 - 180A |
| 0.035" (0.9 mm) | 75 - 250A |
| 0.045" (1.2 mm) | 125 - 350A |
Amperage by Individual Diameter
0.030 ER80S-D2 Amperage
Set 0.030 ER80S-D2 to 50 - 180 amps. Run DCEP. This is the smallest available size. Best for vertical-up and overhead where you need a small, controllable puddle. Start around 115A.
0.035 ER80S-D2 Amperage
Set 0.035 ER80S-D2 to 75 - 250 amps. Run DCEP. This is the most commonly used ER80S-D2 size. Start at 163A for flat work, drop to 75-147A for vertical-up.
0.045 ER80S-D2 Amperage
Set 0.045 ER80S-D2 to 125 - 350 amps. Run DCEP. Largest available diameter. High deposition for flat and horizontal fillet welds on thick plate. Requires 125A minimum to run properly.
ER80S-D2 Suitability Scores
How well this electrode matches common applications. Not a quality rating. all AWS-certified electrodes meet their specification.
What Is ER80S-D2 Good For?
Use ER80S-D2 when the base metal has a yield strength above 50 ksi and standard ER70S-6 would produce an undermatched weld.
Required for HSLA steels in structural, heavy equipment, and pressure vessel applications.
Also used for 1/2Cr-1/2Mo piping root and fill passes where MIG/TIG is preferred over stick.
Where ER80S-D2 Falls Short
More expensive than ER70S-6.
Requires more precise heat input control.
Not suitable for standard mild steel applications where ER70S-6 is sufficient.
May require preheat on thicker sections.
The higher strength weld is more susceptible to hydrogen cracking if moisture is present.
ER80S-D2 at the Gun
The Arc
Smooth, stable arc similar to ER70S-6 but with more body due to the higher alloy content. The 0.5% molybdenum gives the weld metal higher strength and the arc feels slightly stiffer.
Technique
Standard MIG or TIG technique. Push or pull on MIG. Standard dab on TIG. Settings run similar to ER70S-6 on the same diameter wire but the puddle is slightly less fluid.
The Puddle
Slightly more viscous than ER70S-6. The higher alloy content thickens the puddle marginally. The bead profile is similar but with slightly less toe wash. Good penetration on properly prepared joints.
When It Goes Wrong
If you are used to ER70S-6, increase voltage slightly to get the same puddle fluidity. If the bead looks convex and does not wet out, the settings are too cold for this wire.
Which Size ER80S-D2 to Use
| Wire Size | Material Thickness | Application |
|---|---|---|
| 0.035" | 3/16" to 3/8" | HSLA and 1/2Cr-1/2Mo pipe and tubing |
| 0.045" | 3/8" to 3/4" | Standard HSLA and 1/2Cr-1/2Mo pipe welding |
| 1/16" | 3/4" and up | Heavy HSLA structural and pressure vessel work |
What the Spec Sheet Leaves Out
ER80S-D2 is the go-to wire for HSLA steels like A572 Gr.50-65 and A588 where ER70S-6 would undermatch. The 0.5% Mo provides the extra strength and toughness. For chrome-moly piping, ER80S-D2 is only appropriate for 1/2Cr-1/2Mo (P1 group) materials. It does not match P11 (1-1/4Cr-1/2Mo) or P22 (2-1/4Cr-1Mo) chemistry. The correct fillers are ER80S-B2 for P11 and ER90S-B3 for P22. PWHT (post-weld heat treatment) is required on most Cr-Mo joints. Check the WPS before welding.
Bottom Line
This rod was made for structural work. Do not force it into repair situations. ER70S-6 covers what ER80S-D2 cannot.
Setup & Safety Reference
How to Store ER80S-D2
Store in dry conditions. Low-alloy wire; keep wire clean and free of oil.
Shielding Gas for ER80S-D2
| Gas Mix | Common Name | When to Use |
|---|---|---|
| 75% Ar / 25% CO2 | C25 | Standard for low-alloy steel MIG welding. |
| 90% Ar / 10% CO2 | C10 | Spray transfer on thicker sections. |
| 100% CO2 | CO2 | Maximum penetration on heavy sections. |
Low-alloy wire for Cr-Mo steels. Match gas to procedure qualification.
Preheat & Interpass Temperature for ER80S-D2
Preheat varies by base metal thickness. Low-alloy and HSLA steels require careful preheat control. For thicker sections of A572 Gr.50-65 and similar HSLA base metals, 200-300F minimum is common practice.
| Base Metal Thickness | Minimum Preheat (°F) |
|---|---|
| up to 3/4" | 50°F |
| 3/4" to 1-1/2" | 150°F |
| 1-1/2" to 2-1/2" | 225°F |
| over 2-1/2" | 300°F |
Maximum interpass temperature: 500°F
Shielding gas flow rate: 25-50 CFH
Source: AWS D1.1 Table 3.2, Midalloy ER80S-D2 data sheet
Wire Feed Speed for ER80S-D2
Low-alloy MIG wire. Similar feed characteristics to ER70S-6.
| Diameter | Amperage | Wire Feed Speed (IPM) |
|---|---|---|
| 0.030" | 50-100A | 100-250 IPM |
| 0.030" | 100-180A | 250-450 IPM |
| 0.035" | 75-150A | 100-280 IPM |
| 0.035" | 150-250A | 280-550 IPM |
| 0.045" | 125-220A | 80-250 IPM |
| 0.045" | 220-350A | 250-550 IPM |
Deposition Rates
| Diameter | Deposition Rate |
|---|---|
| 0.035" | 3-8 lbs/hr |
| 0.045" | 5-14 lbs/hr |
Fume Generation
Rating: Low
Typical fume rate: 0.2-0.5 g/min
Solid MIG wire. Low fume similar to ER70S-6.
Common Brand Names for ER80S-D2
Look for Lincoln Electric SuperArc LA-75 at your supplier. 3 companies produce ER80S-D2-classified rods.
| Manufacturer | Product Name | Notes |
|---|---|---|
| Lincoln Electric | SuperArc LA-75 | |
| Hobart | HB-25 ER80S-D2 | |
| ESAB | Spoolarc 80D2 |
Full Specs
| Property | Value |
|---|---|
| AWS Classification | ER80S-D2 |
| Process | MIG Welding (GMAW) |
| Polarity | DCEP |
| Positions | flat, horizontal, vertical up, overhead |
| Penetration | medium-deep |
| Coating Type | bare wire |
| Tensile Strength | 80,000 psi |
| Yield Strength | 68,000 psi |
| Elongation | 19% |
| Base Metals | HSLA steels (A572 Gr.50-65, A588), 1/2Cr-1/2Mo steel, High-strength structural steel (up to ~65 ksi yield) |
| Shielding Gas | 75% Ar / 25% CO2, 90% Ar / 10% CO2, 100% CO2 |
| Gas Flow Rate | 25-50 CFH |
| Max Interpass Temp | 500°F |
| AWS Specification | AWS A5.28/A5.28M:2005 (R2021) |
Frequently Asked Questions
When should I use ER80S-D2 instead of ER70S-6?
Use ER80S-D2 when the base metal has a yield strength above 50 ksi (such as A572 Gr.50-65 or A588) and ER70S-6 would produce an undermatched weld. The 80,000 psi tensile strength of ER80S-D2 matches HSLA steels up to approximately 65 ksi yield. For standard A36 or mild steel, ER70S-6 is sufficient and more cost-effective.
What shielding gas should I use with ER80S-D2?
Use 75/25 Ar/CO2 for general MIG welding. For applications requiring maximum toughness, use 90/10 Ar/CO2 or 95/5 Ar/CO2 which reduces oxygen in the weld deposit. 100% CO2 provides deeper penetration but increases spatter and reduces impact toughness. For TIG welding, use 100% argon.
Does ER80S-D2 require preheat?
Preheat requirements depend on the base metal, not the wire. However, because ER80S-D2 is used on higher-strength steels, preheat is more commonly required. Follow the base metal specification or welding code for preheat temperatures. A common starting point is 200-300F for plates over 1 inch thick in HSLA steels.
Where to Buy ER80S-D2
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Manufacturer Data Sheets
External links to standards bodies and manufacturers. These leave GageRef.
Reference data only. Verify all settings against manufacturer documentation and the applicable welding code before use. Amperage ranges are starting points that vary by position, fit-up, and material. Welding involves serious injury risks including burns, electric shock, fume exposure, and fire. This site does not replace proper training, certification, or employer safety procedures. See full terms of use.
Data sourced from AWS A5.28/A5.28M. Amperage ranges are approximate starting points. adjust based on position, fit-up, and material thickness. Always follow manufacturer recommendations and applicable codes.