On Wed, 16 Feb 2005 16:10:23 -0500, Robert Salasidis
wrote:

My understanding is that all ferrous metals are better with sharp
inserts, and positive rake (which I am doing)

Why would you think this?
You are in error.

BTW, Cast Iron is a ferrous metal.
You asked about Brass (did you mention the alloy?)
though, which is non-ferrous.

"Sharp" is not positive rake alone and there's probably
some question as to which edge treatments, like honing,
are sharp.

You can calculate your expected RMS surface finish from
your insert nose radius and feedrate in some cases .... and
a wiper is sometimes limited to a specific feedrate range ...
more may depend on the angle at which your inserts sit
in the cutter body (in this case) and how well you have
matched them all to the same Z plane. IF one is a bit "higher"
than the others ...
Wipers may require specific (special?) cutter bodies too ..
--
Cliff