420 stainless at 45-50 rockwell

[perfecseal mankato]

I never have cut this material before, the

boss wants to try this on the cnc mill.

Any help would be gratefully appreciated.

the material is .078" thick, cutting thru,

some slots 5/16" wide, and pockets.

I come up with about 90sfm for cutting speed for a carbide endmill

[mayday]

send it out for laser or waterjet

[Toolfab]

I would think you would want you SFM up higher than that. Around 120-220 is what I have in my book.

 

But honestly, what the hell do I know?

 

[robk]

perfecseal mankato,

 

+1 Toolfab

 

Reduce your FPT to about .003. We machine this stuff on daily basis, never that thin though. Be careful of vibration.

[Surface]

I just finished up a job of the same stuff. 1/8 thick. It didn't cut bad, but it takes its time. The stuff wanted to harden. You may have better results cutting with oil or air instead of coolant.

I didnt have enough parts to really play with numbers and methods.

[robk]

perfecseal mankato,

 

Not sure of the brand of cutters you're using, but let me suggest Niagara series ELITE SS335.

 

Here's the link;

http://www.niagaracutter.com

[chris m]

200 SFM or so is definitely in the zone as long as the stock doesn't vibrate on you. Depending on the size of tools you choose, put some feed into it; the longer you are in the cut the harder that chip is gonna get. Definitely ramp in to your cuts and use an endmill designed for 'tough' materials. We've had a lot of success with the new Z-Carb line from SGS, Niagara has some good stuff, too.

 

C

[CNCme]

Good Day,

 

Data-flute - 3 flute for stainless

big money but worth it.

 

HTH

Tony G

Almost Employed Senior Programmer

N.E Massachusetts - Southern New Hampshire

_________________________________________

End mills and tooling are like The "AMMO"

And coolant and chips are like the enemy

Under your boots as you advance in the

Manufacturing Battle

--------------------------------------------------

[crazy^millman]

Just some thing off the wall to think about. Get some bon-do and capture the part in it. I would also look at some TiAln endmills and cut it dry with the feed per tooth recommend by robk. You maty find is good to look at the 3 flute to rough it and the 4 or 5 flute high helix to finish it. I would also get me a mister with no water pickup to keep the cutter clean of chips.

 

You can also look at diamond coating but expect to pay 8-10 times the price right off the bat but expect 8-10 times the life. If you are doing long cuts and dont want to possible be replacing cutter in middle of a part then may be worth the extra money. The link you got from Rob should also take you to that line.

 

Good luck just like anything once you do it you got it.

 

Crazy Millman

[Guest]

I've cut 420ss hardened to 48-52 with Garr TiCN coated end mills. I ran at 150 SFM and .001 to .003 per tooth. I flooded the tool with coolant. In my experiance this is not a hard material to cut. The thickness of you material might make the job more diffucult but far from impossable. Good luck.

[Hardmill]

Actually TiAln is what you want. You will be able

to shoot for the 400-600 sfm range. If your

machine is up to the task. Air , No coolant.

 

PEACE

[Chris Rizzo]

That's a lot of SFM (400-600)! How can you get away with no coolant? I would think that work hardening would rear it's ugly head....It seems the general consensus is for no coolant? (or just misting)... I'm cutting mostly soft stuff these days, but please enlighten me regardless.

[Hardmill]

Thats actually part of the beauty of hard machining. "That should'nt work" is thrown straight out the window. You'll take lighter, faster cut at much higher surface footage.

At those speeds coolant will create stress fractures at your cutting edge. Besides TiAln wants to cut hotter than normal. The tools and toolpaths as well as the air makes for good chip evacuation, along with the chip goes the heat.

 

PEACE

 

[ 08-19-2003, 12:14 AM: Message edited by: Hardmill ]

[perfecseal mankato]

Thanks for all the help.

I will start working on this today.

[crazy^millman]

Hey lets us all know what works for you.

 

Crazy Millman