I was slotting some stainless, and the machine started squealing like a pig.
Turns out, the chatter led to some pull-out ...
Attachment 462080
This was at 4000 rpm, 8ipm, 4 flute carbide end mill.
My guess is it sticks out way too much; I didn't have a stubby available.
Also, it's probably cutting too little per tooth, so I'll reduce speed for now until I can get a stubby in the mail.