On Thu, 17 Jan 2008 15:16:04 GMT, "Joe AutoDrill"
wrote:

It may be the steels that test hardest on the Mohs scale are wear
resistant steels that have hard carbides in their crystal structure,
like D2, M4 or some of the CPM metals. The Mohs scale is based on
which material will scratch another, so it seems likely that a steel
that has hard inclusions might rate high on the scale, even if its
bulk hardness (e.g., Rockwell or Brinell hardness) is not unusually
high among tool steels.

So... If I include some diamond dust in the mix, then I can make REALLY
hard steel by their scale, eh? Seems to be a strange way to rate hardness,
but it works for that industry I suppose...

My understanding is the Mohs scale's primary use is as an aid to
identifying materials in the field; rocks and minerals, for example.
I've never seen a mechanical drawing with a callout for Mohs hardness
g.

Crucible has lots of good information online comparing the hardness,
wear resistance, and toughness of tool steels, but it's very poorly
organized, so it may not be worth the effort unless you have a
specific need.

http://www.crucibleservice.com/

--
Ned Simmons