Face Milling 316Lss

[Johnny M]

Looking for some tooling and speeds feeds.

 

Face Milling

Material 316L SS

 

24" x 36"

 

About 3/8 material coming off then onto surface grinder.

 

7 blocks to do

vertical Cnc Direct drive spindle 10 000 rpm

 

Any help would be great

[balnh]

I would look into a feed mill to rip it down then finish up with a face. What kind of tooling do have or are you looking for tooling suggestions? How thick is block? Are you stress relieving? How many HP?

[jlw™]

Can you face both sides? Flip flip flip or it'll warp warp warp.

[Sticky]

How thick is that block? If it's less than 5" thick I would expect it to bow.

[Johnny M]

^{Block is 6.1" thick Machine to 5.75"}

^{Machine both sides leaving 0.003 per side for grinding}

^{No Stress Reliving}

 

^{I have a lot of Seco tools}

^{Highfeed Cutters, inserts 218.19-160T-04-M08 F40M}

 

^{But I'm open to any suggestions also}

 

 

[Sticky]

I would leave more for grinding. How flat do you need this thing? I'd be leaving .03-.06" for blanchard grinding, then surface grind if you need a tighter tolerance or better flatness. FWIW I have done some 22x24" plates of 15-5, 17-4 and 304 and I needed to leave at least .06" for blanchard grinding. But the plates were a little bit thinner, some were 4" some were 5.5"

 

As for speeds and feeds, it's really going to come down to the rigidity of your machine and spindle, and the insert mfg recommendations. 400-600 sfm and .003-.008 IPT is what I would expect from any midrange quality tools.

[jlw™]

I ran iscar feedmills at 440sf and 0.033ipt at 0.04in doc with really good results. Iscar ADKT inserts will leave a nice finish before grind.

 

Trust me on this, the cost of flipping it over and over is less than not being able to hold flatness.

[Sticky]

 

Trust me on this, the cost of flipping it over and over is less than not being able to hold flatness.

 

Yep. Those big blocks of 15-5 I was working on were somewhere around $8k/pc material only. I don't remember how many times we had to flip them, but it was at least 3 times (1 time meaning front AND back).

[Johnny M]

Thanks all for the suggestions and recommendations,

I will probably go with some kind of high feed cutter and do the flip and face procedure ( 3 X )

follow up with a face mill leaving material for the surface grinder

 

Flat within 0.002"

Parallel Within 0.001"

 

Thanks all again.

[civiceg]

 

works great on facing, when possible

[Newbeeee™]

Thanks all for the suggestions and recommendations,

I will probably go with some kind of high feed cutter and do the flip and face procedure ( 3 X )

follow up with a face mill leaving material for the surface grinder

 

Flat within 0.002"

Parallel Within 0.001"

 

Thanks all again.

Never done anything as big as this, but plenty of 304 banana mtl so yes flip and flip.

But these parts are 3ft x 2ft and have a flat tolerance to 2thou and parallel to a thou.

Obviously this is after grinding but is there not a risk of distortion because of heat/pressure when grinding? I would be thinking real real risky tolerances if the parts were only a third of the size...

[Sticky]

Thanks all for the suggestions and recommendations,

I will probably go with some kind of high feed cutter and do the flip and face procedure ( 3 X )

follow up with a face mill leaving material for the surface grinder

 

Flat within 0.002"

Parallel Within 0.001"

 

Thanks all again.

 

That is an "optimistic" tolerance, you might be able to hit it if you flip back and forth on the grinder a few times, but if you don't stress relieve it, I don't see that part maintaining that flatness a few weeks down the road. That said, I have no idea how well stress relieving would work with that size of cross section.

[Josh Kinney -Elite Engineering]

This tool is a straight up brute. No other tool compares for hard metal cutting imho.

 

http://ecat.ingersoll-imc.com/ecat/ProductSeriesDetails.aspx?ID=298145

[Mike@Lustre]

This tool is a straight up brute. No other tool compares for hard metal cutting imho.

 

http://ecat.ingersoll-imc.com/ecat/ProductSeriesDetails.aspx?ID=298145

that is similar to the Iscar Plunge milling cutter we have on 303 SS in plunge milling application we did not see a lot of difference in  insert life over a standard SPCT type insert

[Josh Kinney -Elite Engineering]

The wear is much more predictable. The inserts don't fail in a catastrophic manner.

 

I ran one of the Ingersoll tools against a Mitsubishi AJX in Ti with an interrupted cut and saw 3 times the life.

[jlw™]

Man, that's the opposite of my experience. That black max and an inserted 0.862in chamfer cutter is all I like from Ingersoll.

 

We run a ton of high feed mills. Iscar, Tungaloy, Ingersoll and Mitsubishi are what we have lots of. Of all of them the Ingersoll cutter bodies are junk. If you lose an insert you lose the body. Every other cutter you maybe file a little and back to running.

[Josh Kinney -Elite Engineering]

Look at the insert design. It's bomber.