On Tue, 15 Jan 2008 22:02:19 -0500, Bob Engelhardt
wrote:

One of the shafts on my rototiller-in-rehab was so badly rusted that I
decide to turn it smooth. I've never been able to get very smooth cuts
on the lathe, but with a file afterwards I've managed to get
smooth-enough. Not this time:
http://home.comcast.net/~bobengelhardt/LatheCut.jpg

That is untouched after the cut (except for my fondling it!) I can't
believe it. 'Must have been the material - it was hard, if that would
make a difference.

Oh, that felt good,
Bob

Carbide tends to do that on hard stuff, particularly negative-rake
carbide if the lathe is heavy enough for it.