304 stainless on vf-2

[jprobst]

I have a 2007 haas vf-2, 10,000 rpm 20h.p vmc and just got a job for some lilling on 304 stainless, never machined stainless before, any suggestions? any help is appreciated

[AMCTony]

304 stainless requires patients and prayers. The machine will have no problem with enough power. The thing is that 304 is a pain in the ass to mill. Really gummy. If you can, use 303 stainless. It mills very easy. Also, use carbide mills with a corner radius as much as possible. Insert cutters are prefered.

[gizmo_454]

Stainless is gummy. It's tough to machine, but it can be done. Lower sfm and medium feed are preferable. Use liberal amounts of coolant. Also, try not to let the cutter dwell, because "rubbing" will cause 300 series stainless to work harden and cause premature tool wear. The fella above mentioned inserted mills to be preferable. I am not sure on that one, as I have not used an insert type mill on stainless yet. I have had good luck with solid carbide mills so far in 300 series.

Good luck!

[joecnc1234]

I would suggest using niagra stabilizer end mills they have recommened speeds and feeds cut them back by 30% and take at least 1/2 diameter depth with flood coolant. You should be able to make some parts. The best suggestion is to use 303ss cuts like butter compared to 304ss.
Joe

[InspirationTool]

303 is nice as long as you don't need to weld it. Don't substitute it unless you know for sure the part will never need to be welded.

-Jeff

[rfilabs]

When I cut 304 for the first time, I was amazed at what a tough material to machine it is. I had to hold the work peice very firmly or I had chatter that would chip teeth on the mills. You really have to play with the speeds and feeds to get it right.

I found that using cobalt mills worked well since it can tolerate vibration without chipping pretty well. It also wears slower than HSS. I found carbide to cut well but cost me when a tool chipped.

Some of the cuts I had to make did not allow me to support the material as well as I would have liked.

[rbest27]

3 flute with a small radius at the corner with a hard lube coating and 5 flute high helix hard lube coated endmills. I usually run em dry because they tend to chip with the coolant. Fairly reasonably priced. Niagra or Bentz, there are quite a few companies that make them now. I would run it at about 300 sfm to start..chip loads will vary with size of cut. Drilling isn't that bad just use about 50 sfm and reasonable feeds. Threading is not too bad, just make sure you have the right coating on the tool. I like exotaps for that. Stainless is a great material to machine...304 isn't that bad.