Problem- Milling Stainless Steels

[Rally]

Hi all!
Just opened this thread in hopes someone can shed some light on this problem when milling stainless steel.
Our Shop does its fair share of Stainless milling and turning but the milling seems to be difficult. Most of the tools we use are from Iscar. We just recently started to buy some of the new SumoTech Inserts including the ones the recommended for stainless. They told us to run them dry with only air blowing on the Cutter. What a Joke!! To date we have not found an Insert to hold up.
I would appreciate any Input. Feeds, Speeds and Cutters and Inserts used would be nice to know.

PS: Our Parts are semi large in size, at times we run parts as large as 50" x 30" x 20" tall

Thanks!

[mc-motorsports]

milling and turning are two diffrent beasts...

I HATE MILLING SS!

[beege]

Some stainless steel cuts like butter. You'd have to be more specific in the type of stainless steel you hate. 316? 440C? 17-4? 13-8Mo? I love 303 stainless, 182FM even better!

[stovepipesteve]

i have machined plenty of stainless. it can be a bear at times. especially tapping.
i have had good luck machining stainless using lap cycles with shallow depth passes at high speeds and speeds.
Im using a 1" sumotomo insertable for most of my work. Great cutter capable of some amazing speeds and feeds.
Today i circled mill a piece 20" dia 1045.
it finished at 18. and it is 2"thick.
speed was 3840 rpm at 95.4 ipm with a depth of .05 step down.
i used a spiral down program.(i wouldnt use quite this high rpm/feed on SS)
G90 G0 G54 X11.Y0.D1
G43 H1 Z1. S3840 M3 T2
Z.1
Z0.
G41 G1 X9. F95.4
G2 G91 I-9. Z-.05 L20
G40 G90 G0 Z10.
G53 ZO
G53 YO
M00
your mach. must be able to feed 3 axis to do this, some mach's cant feed in 3 axis.
regaurdless you can still write straight line lap cycles to do stainless work and maintain tool life. ill use standard grade inserts most of the time but will switch out for stainless grade for tougher stuff.

[Rally]

Originally Posted by mc-motorsports milling and turning are two diffrent beasts... I HATE MILLING SS!

Who!! I would have never guessed that!

[Rally]

Originally Posted by beege Some stainless steel cuts like butter. You'd have to be more specific in the type of stainless steel you hate. 316? 440C? 17-4? 13-8Mo? I love 303 stainless, 182FM even better!

Sorry, I thought I put that in the Sentence!
We work a lot of 316 and 308!!

I was just wondering how other people do on that.

[Rally]

Just for the record! We run about 100 to 150 thousand dollar worth a month an I'm not new to machining. I an not talking hobby here!
I run a Hurco VMX64 and will be upgrading to the 84 soon.

[beege]

316? too many people want to go slower when the method fails at higher rates. I believe you need ground inserts, no edge radius. 316 work hardens readily, and you need to get under the hardening. Never less than .003" per tooth, 450SFM unless you're working smaller tools like under 1/4" end mills, then slow down a little so as not to break them. Good luck. I don't like 316 much myself, but its better than 13-8Mo