Need Help!- cutting stainless steel

[YANKS_RINKS]

hi friends,

I have to cut a slot on stainless steel (316), 2.5" deep on a round hub of 6 inches. Diameter on which slot has to cut is 3 inches and width of slot is .660.
My question is that for roughing out this slot which tool should I use? Roughing end mill of 5/8 or inserted end mill(round inserts) of 5/8 and how much depth of cut and feed I can give.

[DSL PWR]

Just start with the same tooling you use for carbon steel (1018, 1045...), and reduce the feed and speed to about 2/3. If the tool and machine can take it run the chipload as high as you dare, to prevent work hardening.

[YANKS_RINKS]

Thanks

i was thinking to do couple of holes before starting to machine. will it help to reduce the chipload

[widgitmaster]

1st I'm not a CNC machinist!

If I were to make it, I would drill one hole to start the slot, then use the quill to plunge cut the slot. By plunge cutting and advancing .050 -.100" per cut, you will only use up the end of the end mill which is easier to sharpen than the diameter.

Use air to blow the chips clear, as re cutting them will kill the end mill. If possible, use a flood coolant! As the tool end wears, just grind it to a radius to extend it's life!

(This is assuming there's only one piece!)

My 2¢

Widgit

[thething84]

i personally would use the inserted end mill, with the correct inserts for stainless steel. If this isn't possible using a High Speed Steel Roughing end mill with rad on bottom to help maintain tool life, Slower spindle speed and get the feed up to as high as is capable of without being excessive, It is really a trial and error thing with feeds and speeds. Depends on the stability of machine etc etc, Flood coolant aswell.