Ted Edwards wrote:

Randal O'Brian wrote:



The Borite turning tools are hardened tool steel and are very tough. MSC
sells them in all the standard shank sizes. The inserts that come with them
are good general purpose types.



You can harden your "tool steel" tools to Rockwell bazillion and it
doesn't matter a tinkers Dam except on the cutting edge which you say
comes from an insert. Rigidity is determined by shape and eleastic
modulus and the elastic modulus of all steels is about the same. A mild
steel holder is just as rigid as an expensive "Hardened Tool Steel
Holder".

The hardened steels generally have a higher yield strength. How many
tool holders have you broken or put a permanent bend in?



I started this thread when I *DID* break a toolholder! But, it clearly was
*NOT* steel at all, but some kind of cast iron material, from the look of
the break.

Jon