Aluminum Solid Wire - ER4043
ER4043 aluminum MIG wire is the general-purpose aluminum filler (AWS A5.10), an aluminum-silicon (~5% Si) alloy that runs smooth, wets well, and resists cracking. It's the go-to for welding and repairing 6xxx-series castings and extrusions such as 6061, with a bright, fluid bead. Spooled in .030", .035", and 3/64".
| AWS Classification | AWS A5.10 ER4043 |
| Alloy | Aluminum-silicon (~5% Si) |
| Shielding Gas / Polarity | 100% Argon · DC+ (DCEP) |
| Best For | 6xxx castings & extrusions (e.g. 6061), general repair |
Frequently Asked Questions
Why choose ER4043 over ER5356?
ER4043 has lower crack sensitivity and a smoother, more fluid arc — better for 6xxx-series base metals, castings, and intricate work. Choose ER5356 when you need higher strength or marine corrosion resistance.
Does ER4043 anodize well?
It tends to turn slightly gray after anodizing. If color match to the base metal matters, ER5356 blends better.
