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

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

On 12/23/2011 10:28 AM, 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 would say the 32 finish and the tolerance on the hole would delegate
how you want to machine it. If it was one part, I would drill and bore
it. But I have alot of boring bars at my disposal here.

Tom

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

As Ed said, a lot depends on the alloy. I used to be in the marine
hardware business and have machined a lot (1) of 85-5-5-5 and
manganese bronze castings. We used round inserts for most of the work
on the 85-5-5-5 castings -- stuffing boxes, stern bearings, etc., and
though we had no specific finish requirement, I'm going to guess it
was in the 32 neighborhood.

The manganese bronze was tougher, and less tolerant of large tool
radii on a long tool.

(1) Enough that after a day of running stuffing boxes on the J&L
turret lathe I'd have what felt like a pound of bronze chips my pants
pockets.

--
Ned Simmons

On Fri, 23 Dec 2011 12:35:47 -0500, Ed Huntress
wrote:

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.


Bronze per ASTM CA836 ( 85-5-5-5)
Remove 333 to reply

On Sun, 25 Dec 2011 11:10:16 -0500, Randy wrote:

On Fri, 23 Dec 2011 12:35:47 -0500, Ed Huntress
wrote:

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.


Bronze per ASTM CA836 ( 85-5-5-5)
Remove 333 to reply

Aha. Ounce metal, formerly known as "leaded red brass."

Machinabilty, 84% of free-machining leaded yellow brass. 'Piece of
cake. g

--
Ed Huntress

I have some Si-Bronze that I turned in nice long curls. It was
so pretty that I put paper down to collect the gold.
I thought that some day I might want to use them as hair curls in a figure.

I was making a tool for the lathe - these were the nuts and double nuts
for End mill and Morse tapers that then are locked into the spindle.
One end screws into the lathe nose gear and the other end locks down on
the far end of spindle. Common on lathes and mills.

Martin

On 12/25/2011 10:23 AM, Ed Huntress wrote:
On Sun, 25 Dec 2011 11:10:16 -0500, wrote:

On Fri, 23 Dec 2011 12:35:47 -0500, Ed Huntress
wrote:

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


Bronze per ASTM CA836 ( 85-5-5-5)
Remove 333 to reply

Aha. Ounce metal, formerly known as "leaded red brass."

Machinabilty, 84% of free-machining leaded yellow brass. 'Piece of
cake.g