5XXX and 6XXX series aluminum alloys are the best for welding overall.

What grade of aluminum is weldable?

Essentially pure aluminum (99 percent pure) and used to carry electrical current or for corrosion resistance in specific environments, these alloys are all readily weldable. The most common filler metal is 1100. 3XXX alloys. This family comprises medium-strength alloys that are very formable.

What is the most weldable aluminum?

5XXX and 6XXX series aluminum alloys are the best for welding overall.