I would turn down the speed, and up the feed rate. Wish you guys would use metric, would be so much easier to read the feeds and speed.
Surfce speed around 120mm/min would work for me.
Is that feed rate really 0.003/rev thats like 0.07mm /rev and its way slow.
Marko
I hate it when people post stuff in metric. So much easier in imperial.. Not that I don't
understand metric, or that I don't know how to do the conversions, but when it comes to
machining, its 99% imperial here, so that is what my brain is used to.
As for the feed, it really depends on what insert you are using. I've found in work hardening
material, that low feeds let you get away with a lot of stuff, like high speeds and big depths,
and wide and deep cuts when milling.
FIRST thing I would do is up the depth of cut. at .015, that's a ton of passes, and that's a lot
of wear on the tip.. triple that to .050 or so, and then maybe drop the speed back to 200sfm or so.
THAT is were *I* would start..
On the low feed thing. There are a couple of parts I make out of 13-8, and the shit is just
miserable. Turning, you simply CAN NOT break a chip, so you end up with birds nests all over the place,
and then crunch your shoulder and everything goes to shit. My 13-8 turning method now is 1 roughing
pass, and one finish.. For the one roughing pass, say .180doc (4.5mm) and feed of .0016" per rev. (0.04mm).
Works like a charm.. YES, One thou and Six tenths, its like the magic #.
13-8 DOES NOT LIKE A HEAVY CHIP. And I can usually take my 13-8 #'s and use them on 304.. I don't do
a lot of 304, so its more about getting it done instead of getting it done fast.. More mill than lathe.
One last question for the OP.. Are you using an insert that is designed for stainless? That
can make all the difference in the world.
"120mm/min" = 4.725 IPM!! Even if you meant Meters (or Metres) instead of mm, that is a ways off either way. Must be my mistake somewhere, just trying to figure you N-EU people out.
