GMAW · Aluminum

ER4043

The forgiving general purpose aluminium filler, whose silicon content lowers the melting range and makes the puddle fluid enough to resist cracking on extrusions and castings.

What the designation means

ER
Classified as both an electrode for wire feed welding and a filler rod for torch welding.
4
The first digit places the alloy in the aluminium-silicon family, where silicon is the principal alloying addition.
043
The remaining digits identify the specific registered alloy in that family, a roughly 5 percent silicon composition.

At a glance

ProcessGMAW
FamilyAluminum
PositionsAll positions with pulsed transfer; spray transfer is best kept flat and horizontal
PolarityDCEP for wire feed welding; alternating current with a balanced wave when torch welded
ShieldingWelding grade argon, or an argon-helium blend on thicker sections for extra heat
Minimum tensile strength27 ksi

Typical uses

  • Welding 6061 and other 6000 series extrusions
  • Repair and joining of cast aluminium components
  • General aluminium fabrication where crack resistance matters more than strength

How it runs

  • Fluid, low melting puddle that wets out easily and is tolerant of technique
  • Less crack sensitive than the magnesium filler on 6000 series base metal
  • Deposit is lower in strength and ductility than the magnesium alloy filler
  • Turns dark after anodising, so it is a poor choice where colour match matters

Storage and handling

Keep aluminium filler sealed and dry, and handle rods with clean gloves; surface oxide and moisture are the main sources of weld porosity.

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