jim rozen wrote in message ...
In article , Lennie the Lurker
says...

My point: why spend extra, several times extra, for something you have
neither the need or the power and rigidity to fully utilize?

For turning abrasive or hard items, carbide is the tool
of choice, even for the hsm-type, using a small machine.
Certainly worth spending extra under those circumstances.

Yes, and I've said in past threads that I do keep a couple of
carbides, but brazed tools, for just such things. Normally, I find
that below RC40, the high speed will do it, but your fpm won't be
anything to write home about. 4140HT is about RC32, and I have no
problems working it with even import HSS. Depending on the alloy,
sometimes HSS will do the job on even harder stuff, but you better not
get in a hurry unless you like to grind. If I were to pick up the 20
inch Monarch that I'm not making a decision on yet, it might be a
different story, but my 12 inch Grizzly isn't a Monarch. As things
are, I'll use the carbide to cut through a case hardening, then switch
back to HSS for the rest of the machining. The half dozen carbides I
have will probably last me for as long as I'm able to move under my
own power. The only other place I make an exception, the carbide
brazed boring bits are cheaper than good HSS kits, by more than half.
other than that, the HSS is more economical for most of the HSM uses.