In sci.engr.metallurgy Martin H. Eastburn wrote:
> Ed wrote: <snip>
>> "MOHS' OR WERNER'S HARDNESS SCALE: WHO SHOULD GET THE CREDIT?
>> http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_60785.htm
>
> Let the usage by metal users go and stop using Mohs Scale.
> It wasn't a metal scale in the first place.
> http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness
Notice the line where it says a file is 6.5 but the table just
below it says steel can be "8". Off hand, a file is the hardest
piece of steel that is "common". ~67hrc from my testing.
The table looks right to me in the area around glass and quartz
since some of my heat and cold treated knife blades can scratch
glass. ~66hrc (1095, 50100-B and even 8670-M)
http://en.wikipedia.org/wiki/Novaculite
Is there anything in an "Arkansas stone" (Novaculite) that's harder
than quartz crystals?
> http://en.wikipedia.org/wiki/Friedrich_Mohs
> Notice the subject that Friedrich had when he invented the scale.
> Martin H. Eastburn
Alvin in AZ
