High-Silicon Brazing Wire vs Standard Aluminum Filler
ER4047 with 12% silicon for brazing and castings vs ER4043 with 5% silicon for general aluminum welding.
Which One Should You Use?
Pick ER4047 if:
Runs on DCEP, AC, 50-180A range. ER4047 full amperage chart
Pick ER4043 if:
Runs on DCEP, AC, 50-250A range. ER4043 full amperage chart
Key Differences
| Attribute | ER4047 | ER4043 |
|---|---|---|
| Silicon Content | ~12% | ~5% |
| Melting Range | 1070-1080F (lowest) | 1065-1170F |
| Fluidity | Maximum - flows into tight joints | Good - standard flow |
| Tensile Strength | 28,000 psi | 26,000 psi |
| Crack Resistance | Excellent - high Si prevents cracking | Good |
| Anodizing | Not anodizable (turns dark) | Limited color match when anodized |
| Best Application | Brazing, castings, thin sheet | General 6xxx series welding |
| Availability | Specialty - less common | Very common - widely stocked |
Settings at a Glance
Machine settings and operating characteristics side by side. For full amperage charts, see the individual electrode pages.
| Setting | ER4047 | ER4043 |
|---|---|---|
| Polarity | DCEP, AC | DCEP, AC |
| Positions | flat, horizontal, vertical-up, overhead | flat, horizontal, vertical-up, overhead |
| Penetration | shallow | shallow |
| Coating | bare wire | solid wire |
| Amps at .045" | 100-250A | 100-250A |
How ER4047 and ER4043 Work Together
ER4043 is the default aluminum filler for 6xxx series alloys. ER4047 is specialized for brazing, casting repair, and applications where maximum fluidity and minimum cracking are needed. The higher silicon in ER4047 lowers the melting point and makes the weld pool flow into tight joints. If you are welding standard 6061 aluminum with TIG or MIG, use ER4043. If you are brazing aluminum, welding castings, or working with very thin material, ER4047 may produce better results.
Common Mistake With High-Silicon Brazing Wire
Using ER4047 for structural aluminum welding expecting higher strength. ER4047 and ER4043 have comparable tensile strength (28 ksi vs 26 ksi), but neither is a structural filler. Their advantage is fluidity and crack resistance. For structural aluminum, ER5356 is the correct choice.
Practical Differences
| Factor | ER4047 | ER4043 |
|---|---|---|
| Common Brands | SuperGlaze 4047, Harris 4047 | SuperGlaze 4043, Maxal 4043 |
Where to Buy
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ER4047 vs ER4043: Common Questions
Which is better, ER4047 or ER4043?
One is not a replacement for the other. Key differences: Silicon Content: ER4047 has ~12%, while ER4043 has ~5%. Melting Range: ER4047 has 1070-1080f (lowest), while ER4043 has 1065-1170f. Fluidity: ER4047 has maximum - flows into tight joints, while ER4043 has good - standard flow. Start with what machine you have and what condition the steel is in.
Can I substitute ER4047 for ER4043?
Check the WPS or code first. Coating chemistry is different (bare wire vs solid wire), so the arc and slag behave differently.
Can I use both ER4047 and ER4043 on the same joint?
ER4043 is the default aluminum filler for 6xxx series alloys. ER4047 is specialized for brazing, casting repair, and applications where maximum fluidity and minimum cracking are needed. The higher silicon in ER4047 lowers the melting point and makes the weld pool flow into tight joints. If you are welding standard 6061 aluminum with TIG or MIG, use ER4043. If you are brazing aluminum, welding castings, or working with very thin material, ER4047 may produce better results.
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/A5.10M.