ER4043 filler metal is a popular aluminum/silicon filler alloy for general purpose welding applications. Features/Benefits: - Moderate strength (28 ksi typical) - Low melting temperature/high fluidity - Low welding smut and discoloration - Low ductility, formability, and lower toughness - Moderate electrical conductivity and thermal conductivity - Excellent corrosion resistance - Low shrinkage rate/reduced distortion - Low hot cracking sensitivity in most applications