Since 2006 Lynn Welding has been approved for resistance spot welding per AWS D17.2.
This specification provides the general resistance welding requirements for aerospace hardware. It includes, but is not limited to, resistance spot and resistance seam welding of aluminum, magnesium, iron, nickel, cobalt, and titanium-based alloys. There are requirements for machine and welding schedule qualification, production witness samples, and inspection and acceptance criteria for aerospace hardware. (Source: AWS.org)