So your still going with hardly any chip load at all?
I'm going to disagree with that... I know the "consensus" in Stainless is to FEED IT!!! FEED IT HARD!!
or it'll work harden on you..
Though if you go and look at ANY manufacturers feed and speed #'s, the stainless #'s are always the lightest feeds.
Quite a few years ago, I had to mess with some A286, and for some reason I decided to call IMCO's tech line.. And he
gave me some #s (lower feed per tooth than I thought) and we got talking about some other stuff I was working on..
TONS of 13-8.. I was running a lot of 1/2" endmills.. .003 per tooth.. 100sfm would give me very good tool life,
120 was the absolute tops, hit 130 and I might as well have just hit them with a hammer and tossed them in the scrap
bucket..
So, the recommendation was 200sfm... BUT only .0015 per tooth, on a 1/2".... Really??? REALLY!!! I ran out the rest of
that 13-8, I had 2 1/2" endmills in there.. When the job was done, one had 24 hours on it, and one had 26.. And I could
have put them back in the container and sold them as new... I was also able to run deeper, wider, and eliminate finish
passes.. Lighter chip load, less tool pressure, I could dig much deeper and much wider, and double my surface speed.
It sounded a LOT better too..
When pulling a BIG THICK chip on a work hardening material.. You are trying to curl that chip, and it gets Freeken HARD..
Its not the material you are going to be cutting you have to worry about, its the material you are trying to curl into the
flute..
Years ago there was an ad on the back MMS, I don't remember the brand, but it was a 304 cutting comparison.. If
you actually looked at the #'s.. 1/2" endmill, in 304.. They had some competitor #'s and "their" #'s..
The "WOO-HOO awesome" endmill was able to run deeper and faster, the difference?? they backed the
feed WAY down to .0014 per tooth...
I'm completely cool with less than .002" a tooth on a 1/2"er.