Facemill for 4140 prehard to ~40-45RC

[rgrin]

Hi!

Looking for some recommendations for a facemill to finish face some subplates I am working on. The process will be facing them in the final use case (plate bolted to pallet). Constrained flatness is the main goal so I think tool pressure will be the biggest issue for me. The plate is about 15"x15"(380mmx380mm). Cutter size I am looking for is in the 2"-2.75"(50mm-70mm). Machine is a Big Plus BT40. Material removal will be about .01" (.2mm) DOC over the whole face with some minor interrupted cuts at the bolt holes . I prefer brands that are easier to get in the USA and I think a tool with a lead angle instead of a 90° shouldering insert might work better. Machine also has high psi thru spindle coolant but not thru spindle air if that factors in.

Thanks!

[nickbe10]

I have always liked the old school Sandvik facemills with the 4 cornered inserts for hard(er) metals. Not the 8 cornered (using both sides).

 

[crazy^millman]

Highfeed style cutter would be ideal for this.

[huskermcdoogle]

On 7/15/2022 at 5:22 PM, crazy^millman said:

Highfeed style cutter would be ideal for this.

For Finishing?   Depending, I guess it could be done, but it is going to push on the plate more than a 45degree cutter will.

I would say a positive positive (positive insert, positive axial/radial rake) style 45 degree facemill will be your best bet.

Kennametal KSOM Mini cutter (KSOM200OF5345M3) with OFKT53AFEN6LB inserts in KC522M grade would be pretty hard to beat.

Otherwise, a Dodeka Mini would be a possible good choice with ground periphery (HNGJ) and LD chipbreaker inserts in KCSM40 grade, it just won't be quite as free cutting as the KSOM.

Both would be very versatile, as there are many insert choices to choose from if needed.

[crazy^millman]

13 minutes ago, huskermcdoogle said:

For Finishing?   Depending, I guess it could be done, but it is going to push on the plate more than a 45degree cutter will.

I would say a positive positive (positive insert, positive axial/radial rake) style 45 degree facemill will be your best bet.

Kennametal KSOM Mini cutter (KSOM200OF5345M3) with OFKT53AFEN6LB inserts in KC522M grade would be pretty hard to beat.

Otherwise, a Dodeka Mini would be a possible good choice with ground periphery (HNGJ) and LD chipbreaker inserts in KCSM40 grade, it just won't be quite as free cutting as the KSOM.

Both would be very versatile, as there are many insert choices to choose from if needed.

Sure one with a high positive rank insert. Not a negative rake or even neutral I am thinking for wear more than anything. You have picked a good choice n doubt.

[Rstewart]

Mitsubishi WSX 445 with one wiper insert installed.  16 finish no problem

[gcode]

I would try a button cutter on this, 1/2" or 3/4" rough inserts

[rgrin]

Thanks for the suggestions!

I was leaning towards the Mitsubishi WSX actually, but a higher up ordered a Seco Quattromill for me since we already stock inserts in our toolcrib. It just arrived this morning and I did a test cut in a scrap piece of 4140. On a part that is 6"x6"x2" held in a raptor dovetail fixture and running the cutter at 600SFM and .003FPT with air blast I was able to achieve a flatness of .0002" or better when checked on the plate and 3 points. The finish is a little smeary probably due to the shallow DOC but it checks as a 15microInchRA so I think I am relatively satisfied. I will be finishing the big 15"x15" plates later this week and we will see if the flatness error gets magnified at those distances. I assume they will