In article , John Albers says...

6. I found a source suggesting using a TNMP insert. The chip breaker
goes clear out to the edge of the insert. Tipping this insert down 5
degrees gives you 5 gegrees end relief and 5 degrees positive back
rake. I think that this insert has chip breakers on both sides so it
could be turned over and used again. DOes anyone know for sure? I
think that this is the best way to go. Has anyone tried this?

Yes. I think it was Ted Edwards (apolgies if this is
wrong) who makes his own holders for these inserts. He
likes that setup a lot. If I did not already have
a set of tpg221 holders from valenite, that's the
way I would go.

7. What effect does the tip radius have. I beleive that the larger
the raduis the smoother the surface finish on turned work. However,
the larger the radius the more power required.

Yes. Also coated inserts invariabley have a "honed" edge
to retain the coating at the cutting point. Because of
this they are not dead sharp and don't cut on smaller machines
quite as well.

Jim

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