ER4047 Aluminum Welding Wire
ER4047 is an aluminum-silicon (Al-Si) filler containing about 12% silicon, near the Al-Si binary eutectic. Its low melting point, excellent pool fluidity and spreading, and strong gap-filling ability make it well suited to brazing and cladding. TGM stocks 1.2/1.6/2.0 mm with stable lead times; it offers good weldability and is straightforward to run.
ER4047 and ER4043 are both Al-Si fillers, but ER4047 carries higher silicon (about 11%–13%), placing it near the Al-Si binary eutectic. The higher silicon lowers the melting point, improves pool fluidity and narrows the freezing range, giving strong spreading and gap-filling — particularly suited to brazing, cladding and overlay work that requires gaps to be filled and lower-temperature bonding.
Where fit-up gaps are wider, low-temperature bonding is required, or solidification cracking is a concern, ER4047 generally performs more reliably than ER4043. Note that its ductility and anodizing color consistency are lower than those of 5xxx Al-Mg fillers, and welds appear grayish; where appearance or joint ductility is important, evaluate beforehand or consider a 5xxx filler. For grade selection, please contact our technical team.
Specifications
| Classification | AWS A5.10 (ER4047) |
| Alloy system | Al-Si |
| Diameters | 1.2 / 1.6 / 2.0 mm |
| Packaging | Layer-wound spool · smooth payoff, no tangles |
| Process | TIG / MIG |
Mechanical (typical)
| Tensile strength UTS (typ.) | ~165 MPa |
| Silicon content | ~12% Si |
| Melting behavior | Low melting · near-eutectic |
| Fluidity | Excellent — for brazing & cladding |
Chemical composition (AWS A5.10)
| Element | Content % |
|---|---|
| Si | 11.0–13.0 |
| Fe | 0.8 |
| Cu | 0.30 |
| Mn | 0.15 |
| Mg | 0.10 |
| Zn | 0.20 |
| Be | 0.0003 |
| Others (each / total) | 0.05 / 0.15 |
| Al | Remainder |
Values are maximum weight percent (single figure) or range; balance is aluminum.
Characteristics & advantages
- Low melting, easy to run: ~12% Si places the alloy near the Al-Si eutectic, giving a lower melting temperature than ER4043 and smoother low-temperature bonding and brazing.
- Good spreading, strong gap-filling: the pool spreads well and fills readily, so even wider fit-up gaps are filled solidly with full, well-formed beads.
- Low cracking tendency: the narrow eutectic freezing range markedly lowers hot-cracking tendency, making it suitable for repairing crack-sensitive aluminum castings.
- Low shrinkage, dense welds: low solidification shrinkage and fewer pores or shrinkage cavities yield sound, dense joints.
- Stable corrosion resistance: corrosion and oxidation resistance remain stable across most general service conditions.
- Smooth feeding, consistent: the layer-wound spool unwinds without tangles and feeds smoothly by hand or machine with fewer stoppages, with stable batch-to-batch consistency.
- Selection note: ductility and anodizing color consistency are lower than 5xxx fillers and welds appear grayish; evaluate separately where appearance or high ductility is required.
Typical applications
- Brazing of aluminum and aluminum alloys, especially where low-temperature bonding and full gap-filling are needed.
- Cladding, overlay and surface repair of aluminum castings.
- Joining of heat exchangers, radiators and HVAC/refrigeration parts.
- Welding and defect repair of high-silicon aluminum castings, such as automotive and machinery cast parts.
- An alternative to ER4043 for crack-sensitive joints and wider fit-up gaps.
Base-metal match
ER4047 suits welding of 1xxx, 3xxx and 6xxx aluminum alloys and many high-silicon castings (such as A356, 356), and performs especially well in brazing and cladding; it is generally not recommended for higher-magnesium 5xxx structural welds. For pairing base metal with filler, see the full selection guide, or contact our technical team for a recommendation.
Other grades
ER4043
The most widely used Al-Si wire, suited to 6xxx alloys and castings, with clean beads and low cracking tendency.
Learn more → Al-Mg familyER5356
The most common Al-Mg wire, with high strength and good corrosion resistance, widely used in structural and marine work.
Learn more → Al-Mg familyER5183
High-strength Al-Mg wire, suited to 5083-type high-Mg base metals and loaded structures.
Learn more → Al-Mg familyER5554
Heat-resistant Al-Mg wire, suited to vessels and piping in long-term elevated-temperature service.
Learn more →Further reading: for the troubleshooting sequence when porosity appears, pre-weld cleaning practice and shielding-gas checks, see the guide to aluminum weld porosity.
Chemical composition follows the AWS A5.10 standard ranges; mechanical properties are typical values — measured data is provided with each batch certificate.
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