Page 1 of 3 123 LastLast
Results 1 to 10 of 21

Thread: Carbide end mills, short life

  1. #1
    Join Date
    Feb 2007
    Location
    Arkadelphia Ar.
    Posts
    539

    Default Carbide end mills, short life

    I've had my mill for some time now, an XLO. My question is about a lack of longevity with end mills. I'm using a mister for cooling and looking up feeds and speeds with FSWiard but seen to loose the edge off of end mills quickly. What am I doing wrong. My latest project is making an follow rest for my lathe, 1018 mild steel, 3/4" carbide 2 flute end mill running at 1000 rpm and .100" depth of cut, probably running at 1/2 to 3/4 of feed rate, three passes in and have lost the edge on the side of the end mill. The coolant is cool mist 77 I think. I am open for suggestions. Thanks

  2. #2
    Join Date
    Mar 2015
    Posts
    3,929

    Default

    Are you slotting? Poor chip evacuation will do that. XLO looks to be a very stout machine so ruling that out unless you are using poor workholding methods allowing the part to flex or move.

    Sent from my SM-G950U1 using Tapatalk

  3. #3
    Join Date
    Aug 2004
    Location
    Sunny So Cal
    Posts
    5,105

    Default

    Quote Originally Posted by quadrod View Post
    I've had my mill for some time now, an XLO. My question is about a lack of longevity with end mills. I'm using a mister for cooling


    1018 mild steel, 3/4" carbide 2 flute end mill running at 1000 rpm and .100" depth of cut, probably running at 1/2 to 3/4 of feed rate, three passes in and have lost the edge on the side of the end mill. The coolant is cool mist 77 I think. I am open for suggestions. Thanks
    I am only gonna trow a shot at it so... 3/4" or 3/8"? That is a massive chunk of carbide. In two flute. Prolly 3/8 assuming

    The two flute deal. Thats an aluminum bit. You really dont need to go esoteric with Carbide Endmills. Center cutting or not? Two or four flute.

    Try a four flute with center cutting, I like center cutting endmills, I wont buy the other stuff cause I am not a factory

    Oh!! And lay off the cooling for the carbide, you will fracture it.
    My old yahoo group. Bridgeport Mill Group

    https://groups.yahoo.com/neo/groups/...port_mill/info

  4. #4
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    3,617

    Default

    Climb milling or conventional milling?

    Chip re-cutting or chatter are most likely causes. Or excessive runout.

  5. #5
    Join Date
    Feb 2014
    Posts
    989

    Default

    Quote Originally Posted by JRouche View Post
    The two flute deal. Thats an aluminum bit.
    No, not really. 2 flute is good for aluminum, but that doesn't make it "an aluminum bit". They're good for steel as well, and highly recommended over a 4 flute for slotting. He's not running a production shop obviously, so the additional feed rate capability of a 4 flute doesn't really matter.

    quadrod - are you taking a cut and then bringing the cutter back over the cut for the next pass so that it's just skimming the fresh cut? That can chip edges of carbide end mills; it's better to either step the part away from the cutter for the return pass, or take a shallow cut. Dwelling at the end of a cut can do the same thing. If you eliminate those two things, your carbide should last a lot longer.

  6. #6
    Join Date
    Dec 2007
    Location
    Montvale, NJ
    Posts
    392

    Default

    Forget coolant with carbide cutters in steel.
    Cutting too slow is no good with carbide either. You want nice blue chips coming off the cutter. The blue color indicates that the cutting heat is being removed with the chip and not staying in the cutter. Sometimes being more aggressive with carbide is better.

  7. #7
    Join Date
    Oct 2006
    Location
    Ivins, Ut
    Posts
    1,462

    Default

    Unless its only moderate cutting, I use coolant almost all the time with carbide inserts. It greatly extends the life of the insert and in some cases improves chip control. There is no danger of fracturing the cutter if the coolant is continuous, and started when the cutting starts.

    For the OP: I use a mist coolant system too, but I use relatively low air flow and 'sputter' the coolant unless higher air flow is needed for chip clearing. You didn't give specifics on the brand of endmill or your actual feed rate. Quality can make a huge difference in performance and durability. Personally, I'd slow a 3/4" 2-flute down to 800 rpm and try again.

  8. #8
    Join Date
    May 2015
    Location
    Somerset UK
    Posts
    2,448

    Default

    You will chip solid carbide cutters if you touch on to steel with the cutter stationary.

  9. #9
    Join Date
    Feb 2007
    Location
    Arkadelphia Ar.
    Posts
    539

    Default

    3/4" 2 flute, first pass was a slotting pass, did 3 slotting passes for a depth of .300", then two side milling passes to widen slot. Brand in this case was kodiak cutting tools, no coatings, feed rate was may be 1 to 1 and a 1/2" a min. The mister I'm using is one I made my self, one tube inside and outer tube, air flows through inner tube, coolant flows through outer tube so it throws droplets onto cutter/work piece. A needle valve can adjust coolant flow.

  10. #10
    Join Date
    Feb 2007
    Location
    Arkadelphia Ar.
    Posts
    539

    Default

    Also I did not have a 4 flute cutter available this time, carbide is expensive.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •