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Thread: Brass turning cutting fluid

  1. #1
    Join Date
    Jun 2015
    Location
    St Louis Bench Rest Club
    Posts
    24

    Brass turning cutting fluid

    Now that I retired I have a little more time and I'm getting back to cutting my own brass. Its been 20+ years since I did it with a K&M. Actually two K&M's. One for the first cut and a second for the final cut to get to .00088 for PPC BR shooting. Now I have a Neilson's Pumpkin and just finished wading through the "how to" in order to adjust depth and neck cut thickness. Its a lot easier this time since I'm shooting a .268 neck and I can make the cut in one pass. Before I launch I wanted to see if there was a general consensus on cutting fluid. Tony suggested a mix of Mobil one and STP, RCBS case lube, Hornady one shot plus others. Don Neilson suggest one quart 20W-50 synthetic to 15 ounces of STP. Dan Lilja uses a cutting fluid like Cool Tool. Couldn't find much on the search feature specific to cutting fluid/oil on the forum so I though I'd ask. I have the tooling set up on an end mill at about 500 fps. The Pumpkin is held level with a drill vice and a locking handle to hold it. Allows pretty easy centering of the case to the cutter. Thanks, Bill.

  2. #2
    Join Date
    Jun 2012
    Location
    West central NH
    Posts
    384

    Am I doing it wrong?

    I hate to sound uninformed, but I was not aware that the use of cutting fluid for turning necks was widespread.

    I am turning using a K&M tool and an electric screw driver, which is very low speed. I use the proper expander mandrel and I lube the turning mandrel with imperial sizing wax every second or third case. Am I perhaps damaging my brass? I do things at a slow enough pace that nothing gets too warm.

  3. #3
    Join Date
    Dec 2017
    Posts
    101
    your cutting. lube is a good idea.
    i use a drop of FP-10

  4. #4
    Join Date
    Feb 2003
    Location
    Jeddo, Michigan
    Posts
    3,608
    I'm using one of my neck turning lathes turning at 140rpm. I use a Pumpkin for the 6mm and couple K&M for the 6PPC. I use Don Neilson's recommended 20w-50 Mobil synthetic and STP for mandrel lube. I don't have any major heat issues.

  5. #5
    Join Date
    Nov 2006
    Location
    ME
    Posts
    1,411

    Hey Big F

    Quote Originally Posted by FBecigneul View Post
    I'm using one of my neck turning lathes turning at 140rpm. I use a Pumpkin for the 6mm and couple K&M for the 6PPC. I use Don Neilson's recommended 20w-50 Mobil synthetic and STP for mandrel lube. I don't have any major heat issues.
    you must be keeping your mouth closed?

  6. #6
    Join Date
    Feb 2003
    Location
    Lower Dakota Territory
    Posts
    1,565
    Marvel Mystery Oil does a nice job, as well. -Al

  7. #7
    Join Date
    Jul 2005
    Posts
    285
    Lube on the pilot for the case neck is even more important.

  8. #8
    Join Date
    Dec 2017
    Posts
    101
    I put one drop on the neck,
    then touch the neck to the pilot.
    Cut
    Clean with compressed air also cools.

    Quote Originally Posted by brickeyee View Post
    Lube on the pilot for the case neck is even more important.

  9. #9
    Join Date
    Jun 2015
    Location
    St Louis Bench Rest Club
    Posts
    24
    So I'm going with Premium Metal Tapping Fluid - 16 FL. OZ. Threading and Cutting Oil since it was on Amazon since I could get it by Tuesday. We'll see how things go, In my heart the recommendation of sizing wax or Neilson's recommendation of one quart of 10 w 50 synthetic and 16 ounces of STP would be fine for most of us. But I'll try the cutting fluid first. The wording of cutting / oil seems and the way Tony phrased it convinced me that the proper cutting speed, coolant any fluid of a fluid may work. Wish me luck. Bill.

  10. #10
    Join Date
    Feb 2003
    Location
    Melbourne, AUSTRALIA
    Posts
    51

    Turning Fluid

    Quote Originally Posted by Wm Cook View Post
    So I'm going with Premium Metal Tapping Fluid - 16 FL. OZ. Threading and Cutting Oil since it was on Amazon since I could get it by Tuesday. We'll see how things go, In my heart the recommendation of sizing wax or Neilson's recommendation of one quart of 10 w 50 synthetic and 16 ounces of STP would be fine for most of us. But I'll try the cutting fluid first. The wording of cutting / oil seems and the way Tony phrased it convinced me that the proper cutting speed, coolant any fluid of a fluid may work. Wish me luck. Bill.
    The tapping fluid will work fine. A drop on the mandrel and a drop on the neck is all it takes

  11. #11
    Join Date
    Jul 2005
    Posts
    285
    I have a couple tight neck barrels for a Panda varmint rifle.

    To make sure I hit the desired clearance the brass is thinned down in two steps.
    The first one removes all but about 0.0010 of whatever needs to come off.
    The second removes that last little bit.

    I can easily control down to 0.00010 (and yes, it is a PITA to set up.things and measure).

  12. #12
    Join Date
    Nov 2006
    Location
    Augusta, Maine & Palm Coast, Fl
    Posts
    5,642

    Now there's some Hi Tech

    Quote Originally Posted by FBecigneul View Post
    I'm using one of my neck turning lathes turning at 140rpm. I use a Pumpkin for the 6mm and couple K&M for the 6PPC. I use Don Neilson's recommended 20w-50 Mobil synthetic and STP for mandrel lube. I don't have any major heat issues.
    Synthetic Oil and Andy Granatelli? WOW!

    Pete

  13. #13
    Join Date
    Feb 2003
    Location
    Austin, Texas
    Posts
    869

    Just a drop...

    Of RCBS case lube does the job for me along with my JACO cutting tool. I cut Savage 300 necks to .008 with one cut as part of forming 30HBR brass for my Hunter class rifle. Cheap and lasts a long time.

  14. #14
    Join Date
    Dec 2003
    Location
    washington.........STATE that is.
    Posts
    9,399
    I sometimes do hundreds of cases. Buncha' turning tools.

    I dip the casemouths in a thin layer of engine assembly lube https://www.amazon.com/Permatex-8195...+assembly+lube and drop the neckturning tool into a bowl of water between cases.

    Everything stays the same temp, for hours and when I'm done I just blow out the turner with air and let it set to dry fully before putting it away.

    'Course in my case, it never seems to be put away!

    LOL

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