A while back someone asked whether powder coating grade 5 bolts would
affect their strength. (Carl Musson?)
I finally got an answer of sorts from the metallurigcal engineer I work
for (who consulted w/ his son, a welding instructor)
Grade 5 and less are not high-carbon bolts. The verdict was to take some
samples, power-coat them, and try to destroy them. So much for science.
Be forewarned that some bolts sold as grade 5 are only grade 3; it depends
on the manufacturer. Some put 3 checks on a bolt & call it grade 3, some
call it grade 5. Caveat emptor.
Incidentally there is also some thoughts about having hard/soft bolts.
For example, cooling the bolt in water will make it brittle; casting it
into lime or letting it air-cool will make it soft (annealed).
So there you have it. I hope someone can manage to test the bolts, as I'm
curious and I don't have the facilities to do such an experiment :-(
-Malcolm
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