I’ve made a few brass branding irons. I used standard woodworking v-bits with good results. I just make sure I use one of my older bits.
I recently was asked to produce a 3d carved brass item for a client. The item was very intricate and would require a very fine tipped bit. Since I had just performed a few adjustments to the ShopBot to improve accuracy, I knew the machine was up capable of the detail. My questions were related to bit selection and speeds. I started to do some research to find what the experts recommended.
Tapered, ball nose bits with a very small tip are the way to go. Machines like the Carvewright have been delivered with this kind of bit since their inception. The main reason is that they perform quite well on the small scale carving that is generally performed on these machines.
These bits are generally up-cutting to aid in removing chips. They often come with a coating that is intended to extend edge life or keep cutting temps low.
The bit I chose to try out was the 1/4″ shank, 6.2deg tapered ball nose bit made by Amana Tools.