As much as this is really an ASME question, It seems that many of the individuals that visit this website are as experienced in ASME work as AWS. I am constantly researching the compatibility and most appropriate filler metal for performing welds joining high temp stainless boiler tubes to themselves or to different grades of typical chrome tube materials. In the past, I've used many different combinations of recources for this information, keeping in mind that in most cases, stress values play a big part in the materials selection. Since stress values at temp. are not listed in the filler metal specifications, I try to find the base metal that compares to the filler metal, and check the stress values at temp. for those. I have qualified WPSs that use F-43 filler metals like ERNiCr-3 when joining 304H material to itself and to P-5A material. Are you aware of any easy method of filler metal selection for applications like I've described?