A while back I posted about a little part that required milling some 46-
49Rc stainless steel. I programmed it and set it up last week and it ran just fine. I ended up getting the key cutters from Harvey Tool. They were an "off the shelf" item from them.I ended up starting at 200 SFM for most of the milling. The consensus was that was probably a little high but I figured I could always change the end mills and slow it down if things started to melt. So far it looks like I might be able to kick it up a little if anything. I ended up using a high end cutting oil for coolant. I think that in this case the oil helps as it keeps the end mills and inserts from thermo-cycling.
I'll post some more info after the competition has a chance to flounder and fail. I'm using some brand new milling tools (some are actually prototypes) from a company that's been around for a while but hasn't been on the cutting edge in recent years. It looks like things are changing for them. These new tools kick ass for milling on a lathe. No chatter at all. And I'm getting after it pretty hard.
Thanks for the advice.