Form: This specification covers an aluminum alloy in the form of welding wire. Application: This wire has been used typically as filler metal for gas-metal-arc or gas-tungsten-arc welding of heavy sections of aluminum alloys of similar composition to produce joints having inherently low dilution ratio of base-metal to weld-metal@ and where the weldment may require solution and/or precipitation heat treatment@ but usage is not limited to such applications.