On Fri, 23 Dec 2011 10:28:50 -0500, Randy333
wrote:

Any here have some real experience machining bronze castings? I have
to do a job with a 4"deep bore 1.750 dia. and a 32 finish. Can I do
it with a long carbide end mill? I use 4" LOC hanita vari-mills in
cast iron and they leave a really sweet looking finish when they are
new. (when they get dull the start to chatter).

Or is this boring head territory? I have a tooling guy quoting me
some boring heads.

Remove 333 to reply.
Randy

I have only slight experience with manganese bronze turning and
boring, but be aware that just "bronze" isn't much help in figuring
out how to machine it. Different grades of cast bronze range from 8%
to 90% of the machinability ratings of free-machining brass. If you
know what you have, I can give you its machinabilty rating.

Some of them are exceedingly tough and gummy. Others cut like yellow
brass.

--
Ed Huntress