We are running a 1.970” diameter, 12 flute solid carbide cutter mounted to a 1” HSS shank. The cutter is .236” wide with .094” radius on both corners.

We are cutting a slot that finished at .406” wide with a 1” radius.

The material is 4340.

We are having trouble eliminating chatter. We are climb milling on a WFL Mill turn. We’ve tried .01” radial DOC for finish pass, we’ve tried .005” radial DOC for finish pass. A spring/free pass seems to help. HSK100 tool holder, the part setup is relatively rigid. The finish looks great on the exit of the tool path but chatter on the entry. It’s cutting a straight line to an arc to a straight line.

Do you think conventional tool path would help?

I don’t have much experience with a tool of this type. What SFM would you recommend? Chip load? I believe a lot of teeth are engaged in the cut at any given time. How is this determined/calculated?

Thanks in advance for the support.

- Branden