Small face mill for stainless

[Comatose]

I'm face milling 416 steel with a 16k spindle Brother (no BBT) and need a recommendation for a face mill. Taking off about .04" total. Presently I'm just using a 3/8 4 flute endmill, which works fine but it takes more time than I like, and to get a usable surface finish I have to rough leaving .005 and then come back over it to finish.

Details:

I need something with a relatively square shoulder to clear the fixture. .03" corner radius max.

I'm hoping for something pretty small, because the 16k spindle doesn't have a ton of guts down low, and the standard 30 taper isn't all that rigid. Ideally something like a 1" diameter with three or four inserts.

I need a decent surface finish, but it gets hardened, tumbled and then bead blasted after machining, so it doesn't need to be a mirror.

Prefer something where the inserts are cost effective, either due to long insert life or cheap inserts. This is a long running job so saving ten cents a part in inserts adds up.

416 is a very free machining grade, it cuts as easily as 303, if not easier.

Thanks for any recommendations!

 

[gkoenig]

I'm using one of these in titanium to get fantastic face finish results. Lots of insert options, just a little beast in a Big+ 16k Speedio.

R220.69-01.50-06-10AN | Secotools.com

R220.69-01.50-06-10AN 02694915 Milling

www.secotools.com

 

[Mtndew]

Sounds like a perfect job for a 1" Sandvik R390
https://www.sandvik.coromant.com/en...ortProperty":"ORDCODEUSA","isAscending":true}

 

[chad883]

ISCAR Cutting Tools - Metal Working Tools - T490 ELN-08 : 3105503 - T490 ELN D1.00-4-W.75-08C

T490 ELN-08 : 3105503 - T490 ELN D1.00-4-W.75-08C

www.iscar.com

I use this in our live tool lathe. cuts nice and has 4 edges per insert

 

[mmurray70]

Sounds like a perfect job for a 1" Sandvik R390
https://www.sandvik.coromant.com/en-us/search/products/tl_cor/mil_cor/milsq_cor/milsq_ind_cor?q=RA390&filter={"refiners":{"TIBPAvailability":["Available"],"IsTailorMade":[0],"DC":[1]},"tableType":"Standard","selectedColumns":["DC","KAPR","CPDF","CICT"],"sortProperty":"ORDCODEUSA","isAscending":true}

Im big fan of the R390 in steel, but I find them terrible in stainless. Maybe 416 might be easier.

Might be better off sticking with solid carbide. For shallow depth like that use 5 or 6 flute 3/8 EM and crank feed up. This will probably give you better results then a facemill. I used some 5 flute Garr endmills from mcmaster carr once for similar job. Facing 304 stainless with shallow depth of cut and they worked well. Look for a tool with sharp edge prep and small corner rad.

 

[Mtndew]

but I find them terrible in stainless

We you using the grade made for stainless?

 

[mmurray70]

We you using the grade made for stainless?

Yeah it was few years back. We tried few different grades, different speeds and feeds, coolant and no coolant, spoke to rep, etc etc. Nothing seemed to work well at all. I always have much better luck with solid carbide in 304/316 stainless.

 

[TrollTuner]

I have an Iscar Shell mill 1-1/4 HM390 -07 Works great in smaller Stainless and Ti parts. Looks like YG has a similar one now and their stuff is a lot cheaper.

Initially there wasn't a 1/2" arbor but maritool whipped one up. We run the 1.5" HM390 -15 in aluminum.

 

[garyhlucas]

I look at these threads because I find it interesting from an electrical engineering point of view. Spindle motors have torque vs power vs rpm factor that is important in getting the maximum metal removal rate. For any given combination of spindle, cutter and material there will be a sweet spot for maximum removal rate and finish. It is virtually impossible to use full spindle motor power. So my curiosity lies in how close to optimum anyone actually gets. Probably a question that can only be answered by a shop doing the same parts in the millions, where nailing it would pay off big time.

 

[Conrad Hoffman]

Armchair guess- even with the best inserts there's a limit to SFPM and also a sweet spot. I'd guess if making parts in the millions you'd just buy a machine with the necessary HP at the optimum speed for the job. Never been in that situation. Usually it's get the part out with what you've got and try not to lose your shirt.

 

[Pete Deal]

I don’t have a specific tool in mind but it’s been my intention to get a bt30 threaded holder and one of the thread in cutter tips to be used as a mini face mill.