ronschreck
Well Known Member
An Xray would be the only non destructive way that I know of and you would need an expert to read the result. If you took them to someone who operates a Tig welder professionaly, they probably know what they are doing. It is not an easy skill to aquire.
Gil Alexander has found that AN490 threaded rod ends are heat treated to Rockwell C25 to C30. While you may not have a Rockwell hardness tester in your shop, they are not that uncommon. Rockwell testing would be considered "destructive" in some cases, depending on the test specimin. During testing a small carbide ball or diamond indenter is pressed into the test sample. I doubt this would be considered destructive in the case of a threaded rod end.
I'm anxious to see the NTSB Material Lab report on the Velux crash because the failed rod end was probably tested for Rockwell hardness. If the part was welded and quenched improperly there could be a significant change in the hardness (brittleness) of the part. Additionally, Rockwell testing only determines surface hardness. Perhaps the NTSB used other testing methods.