Machining Brass on CNC Equipment

Bits and feed rates for cutting 3/8-inch brass. March 1, 2006

I would like to cut some shapes out of 3/8" thick brass on my CNC router. Does anyone have suggestions for tooling, speeds, or lubrication? The machine is a Techno Premium with a 10 HP motor.

Forum Responses
(CNC Forum)
From contributor A:
Buy a copy of Machinery’s Handbook. This book is the know-all for metal machining.

From contributor B:
Onsrud makes a series of O flute bits for aluminum that I found to work great in brass as well. I run about 14,000 rpm and 150 IPM feed. You will have to make multiple depth cuts depending upon the size of your tool most likely .100 deep. I also use a mister can and mist with tap magic to keep the tool from getting sticky.

From the original questioner:
How thin of a bit can you get away with - 1/8" or 3/16" diameter? I would like to have inside corners as sharp as possible.

From contributor C:
If you want sharp corners you could use a 1/8" bit to machine just the corners then use a 1/4" bit to machine the shapes.