IIRC, GO claimed to apply some sort of plasma-coating technology or "plasma-infusion" or whatever they called it. I can't recall, but back then I looked it up and it is most definitely some kind of very hiigh tech extremely wear resistant coating. Whatever the case, I know mine has seen and survived sustained 180 deg C head temperatures... It did not run right that hot (vapour locking) but it did not hurt it either.