ER4043 vs ER5356: Which Aluminum Welding Wire to Use
ER4043 is the default aluminum wire for 6061 and cast aluminum. ER5356 is required for 5xxx marine alloys and anodized work. The base metal determines which one to use.
ER4043: 6061, 6063, 3003, and cast aluminum. ER5356: 5052, 5083, 5086 aluminum (required).
Which One Should You Use?
Pick ER4043 if:
6061, 6063, 3003, and cast aluminum. Most general aluminum repair. Automotive aluminum. When crack resistance matters more than strength. When the weld will not be anodized.
Runs on DCEP, AC, 50-250A range. ER4043 full amperage chart
Pick ER5356 if:
5052, 5083, 5086 aluminum (required). Marine applications. When the finished weld will be anodized. When fillet weld shear strength is critical. Boat hulls, fuel tanks, structural marine.
Runs on DCEP, AC, 50-250A range. ER5356 full amperage chart
Key Differences
| Attribute | ER4043 | ER5356 |
|---|---|---|
| Alloy Composition | 5% silicon (Al-Si); better wetting and flow characteristics | 5% magnesium (Al-Mg); higher strength but more crack-sensitive |
| Tensile Strength | 26 ksi | 38 ksi |
| Anodizing | Weld turns dark/discolored after anodizing; poor color match | Good color match after anodizing; preferred for visible anodized work |
| Crack Sensitivity | Less crack-sensitive; better for castings and repair work | More crack-sensitive; do not use on 6xxx castings or high-silicon alloys |
Settings at a Glance
Machine settings and operating characteristics side by side. For full amperage charts, see the individual electrode pages.
| Setting | ER4043 | ER5356 |
|---|---|---|
| Polarity | DCEP, AC | DCEP, AC |
| Positions | flat, horizontal, vertical-up, overhead | flat, horizontal, vertical-up, overhead |
| Penetration | shallow | medium |
| Coating | solid wire | solid wire |
| Amps at .030" | 50-130A | 50-130A |
| Amps at .035" | 70-180A | 70-180A |
| Amps at .045" | 100-250A | 100-250A |
How ER4043 and ER5356 Work Together
The AWS Aluminum Filler Metal Selection Chart (in A5.10) is the definitive reference. For 6061 base metal, both 4043 and 5356 are acceptable, but 4043 is preferred for crack resistance and 5356 is preferred for strength and anodized color.
Common Mistake With ER4043
Using ER4043 on 5xxx alloys. The silicon-magnesium interaction at the weld boundary creates a low-melting eutectic that causes hot cracking.
When It Matters
The Job
You are TIG welding an aluminum motorcycle frame repair. The base metal is 6061-T6 aluminum. You have both filler rods on the bench.
Which Rod Wins
ER4043 flows smoother and produces a brighter, shinier bead on 6061. ER5356 gives you higher shear strength and better color match after anodizing. For a structural frame repair on 6061, ER4043 is the standard recommendation from the Aluminum Association. ER5356 is the pick if the frame will be anodized after repair.
Where It Breaks
Using ER5356 on castings or 4xxx-series aluminum causes hot cracking. The magnesium content does not play well with high-silicon alloys. Check your base metal before picking filler.
The Sensory Difference
ER4043: ER4043 feeds into the puddle like butter. The bead wets out easily and flows into the joint. The finished weld has a bright, almost mirror-like surface. Less sensitive to contamination than ER5356.
ER5356: ER5356 is stiffer in the hand. The bead is slightly duller and does not flow as freely. It requires more heat input to wet out. The trade-off is higher strength and better fatigue resistance in service.
Where to Start
Start with ER4043 when learning aluminum TIG. It is more forgiving and flows easier. Move to ER5356 when you are welding 5xxx-series alloys or need anodize-compatible welds.
Practical Differences
| Factor | ER4043 | ER5356 |
|---|---|---|
| Common Brands | SuperGlaze 4043, Maxal 4043 | SuperGlaze 5356, Maxal 5356 |
Where to Buy
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ER4043 vs ER5356: Common Questions
Which is better, ER4043 or ER5356?
One is not a replacement for the other. Key differences: Alloy Composition: ER4043 has 5% silicon (al-si); better wetting and flow characteristics, while ER5356 has 5% magnesium (al-mg); higher strength but more crack-sensitive. Tensile Strength: ER4043 has 26 ksi, while ER5356 has 38 ksi. Anodizing: ER4043 has weld turns dark/discolored after anodizing; poor color match, while ER5356 has good color match after anodizing; preferred for visible anodized work. Start with what machine you have and what condition the steel is in.
Can I substitute ER4043 for ER5356?
Check the WPS or code first. Penetration differs: ER4043 is shallow, ER5356 is medium.
Can I use both ER4043 and ER5356 on the same joint?
The AWS Aluminum Filler Metal Selection Chart (in A5.10) is the definitive reference. For 6061 base metal, both 4043 and 5356 are acceptable, but 4043 is preferred for crack resistance and 5356 is preferred for strength and anodized color.
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 A5.10.