John2005 wrote:
Thanks for the feedback guys,

After reading your replies, I searched online for NAK55 and DH2F. I
will also check into the Viscount.

I read something about one of the grades in a "hi hard" condition of
45/48 RC, which would probably have a high compressive yield strength
in that hardness.

NAK has a grade this hard but you might also be refering to something known
as Super P-20.
Thyssen makes it.

At about what point in general would a pre-hard
steel be too hard to really machine effectively ?

Tooling for hard milling has come a long way over the years.
People are machining 60 RC D-2 these days from the start.


--

John R. Carroll
www.machiningsolution.com