I have a tube to sheet fillet weld with 6061, .035" tube wall thickness, .625" diameter welded to .040" sheet (such as in D17.1 Figure 5.9).  Per Table 5.5 of D17.1, I am required to have a bend test performed for weld procedure qualification, except that "the use of a macro examination in lieu of bend testing shall be permitted only if the material is such that the specimen cannot be bent within dimensional limitations of AWS B4.0... or Annex C" (note c).

As far as I can tell, tube to sheet fillet welds are not addressed in AWS B4.0.  Annex C allows for metallographic examination only for base material thicknesses over .063" and is silent of smaller thicknesses.

I have contacted 5 different test houses and they have all told me that a bend test is not required, but if it was, they still couldn't perform it because the wall thickness is small enough that the parent material would bend well before the weld joint.

Does anyone have advice on a path forward?  I have to either come up with an amazing argument to convince our customer or figure out how to perform a bend test on this sample.