Stainless is kicking my #$%%#$

[ghyman]

I appreciate the great volume of replies and good information!

I'm going to build a small support for the fixture to keep it more rigid, and for the time being drop to a smaller diameter cutter. (We're a sheet metal shop; the machining side is <5% of our business, so they don't like to spend a lot on tooling... but I'm working on them!)

Cutting without coolant has always been scary for me, but I am going to give it a try. Call it Old dog / New tricks... (And I remember when all this was farm land... and Get Off My Lawn!)

The coolant is a little richer than what I am used to as well, but the majority of our parts are 625/718 inconel, a little titanium, and a little Hastelloy-X.

And Packers... Our distributer is just that... a distributer. No tech support whatsoever. I have asked Kyocera several times, but never any reply. They have 2 different catalogues on their site, one says this is a cast iron grade, the other says it is the best choice for stainless (including speeds/feeds for SS!)

Pixman, I am interested to hear what you have!

Thank you all again.

[PixMan]

Ghyman,

You have a PM.

[Packers]

321 SS can actually be considered a High Temperature Alloy. High Chromium and High Nickel content plus Titanium make this one more difficult to machine than most 300 series SS. Cutting speeds for this material may be 200 SFM or even lower 150 SFM. Sometimes if a manufacturer does not have a dedicated HTA grade they will recommend the CI grade due to wear resistance needed to machine cast iron. The recommendation for higher feed rates is correct in order to prevent work hardening. Look for BUE (built up edge) on the inserts. If you see that run a higher feed rate. From the looks of your inserts that CA2325 grade might be too hard. Should try the PR660 grade which is dedicated to SS machining and a lot tougher than the CA2325. Maybe try smaller WOC, no more than 1/2 of the cutting diameter. Since your setup is a little weak I would make sure that the DOC is not much more than the radius on your insert. Just a freebie for my cnc zone friends

[Packers]

oh yeah i would recommend a different cutter too, maybe one with more axial rake angle.