"Jon Elson" wrote in message
...
snip---

Pretty much all standard milling
cutters are set up for some positive rake. So, there shouldn't be any
concern
for rigidity and power when making the decision between the cutting
tool materials.

You've apparently never encountered a large insert shell mill. Negative
rake, and can move metal, even chrome moly, at a rate that boggles the mind.
Requires one hell of a lot of HP, however. I recall watching a vertical
Milwaukee grunting like crazy swinging a large one. Mill had 10 hp at the
spindle.

Harold