It seems to me that Rockwell testing does not take into account the "depth"
of hardening. The dimple test does not probe further than a ten-thous or so
below the surface. Eg, chilled and nitrided materials may indicate the same
Rockwell numbers, but IMHO nitriding is the preferred treatment for long
I'd advocate testing through destruction, which means purchasing a
few more of the items than required and ensure that all materials
came from the same production run.
I'm not an expert; just offering an opinion.
Shane Ingate in Maryland
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