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Thread: Insert tooling for threading

  1. #1
    Join Date
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    Default Insert tooling for threading

    Is there any such for doing this like the one in the pix?? This is to cut "Right hand" threads from the inside (botton of the hole) out, on the back side of the hole running the spindle in reverse. NOT anything to do with "Left hand" threads. I've managed to grind a few bits for a boring bar and the one in the pix is carbide but costs a fortune (relatively). If I spend that kind of money I would like to have the option of replaceable inserts. I've tried all combinations of wording in search engines and the only thing I find is the ones in the pix. All the inserts that "look" like that shape say for "External threading". So I assume (dangerous I know) it's because they don't have the needed "front" clearance for the internal curve.
    ??? Any pointers?


    Thanks. ...lew... here is the version I've made that works.

    Last edited by Lew Hartswick; 02-13-2018 at 06:18 PM. Reason: add pix 2

  2. #2
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    ISCAR do these -
    http://www.iscar.com/Ecatalog/item.a...FSTYP=M&isoD=1

    LH and RH tips for boring, back boring, grooving and threading down to 8mm bores.
    If you benefit from the Dunning-Kruger Effect you may not even know it ;-)

  3. #3
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    I use these.............http://www.vargus.com/thread-turning. They also have a program you can download. Enter a thread pitch and dia. and it will tell you which insert and anvil to use along with DOC and number of passes etc.

    JL...............

  4. #4
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    Default

    Bokum makes them for threading, grooving, and chamfering.
    They are form relieved, and you just sharpen the top moving it radially each time...i.e. grind off the cutting edge, not the heel.

  5. #5
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    Hi,

    Even Banggood will sell you an internal threading tool with inserts https://www.banggood.com/SNR0010K11-...r_warehouse=CN

    I bought one for a one-off job, 50mm x 1.5mm. Dirt cheap and worked a treat on the case hardened tube.
    If you think you understand what is going on, you haven't been paying attention.

  6. #6
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    Either you folks are finding things in those ads that I cant or I'm not making myself clear about what I'm looking for. All I see in all those ads are for threading right to left (toward the headstock) on the "front" of the hole for a right hand thread. I'm trying to thread from left to right (toward the tailstock) on the back side of the hole. A conventional right hand thread, the spindle running in reverse. None of the inserts seem to permit that. The Bangood bar, and one other I found look like it would hold the insert OK but all of the inserts that fit say for external threading. (? tip clearance ?)
    ...lew...

  7. #7
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    Quote Originally Posted by Lew Hartswick View Post
    Either you folks are finding things in those ads that I cant or I'm not making myself clear about what I'm looking for. All I see in all those ads are for threading right to left (toward the headstock) on the "front" of the hole for a right hand thread. I'm trying to thread from left to right (toward the tailstock) on the back side of the hole. A conventional right hand thread, the spindle running in reverse. None of the inserts seem to permit that. The Bangood bar, and one other I found look like it would hold the insert OK but all of the inserts that fit say for external threading. (? tip clearance ?)
    ...lew...
    Many of those import threading tools are for internal threading, they are configured like a boring bar. To thread spindle towards tailstock, with the spindle running in reverse, you simply flip the boring bar, putting the insert facing down and to the rear of the spindle. Of course, if you need to cut up tight to a shoulder down in the bore that presents a different problem, those insert boring bar type tools can get pretty close though.

  8. #8
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    Flipping the boring bar will not work with a laydown tool, you need a left hand tool. The old style boring bar with a hss tip held in with a screw will work in reverse as the tip can be inverted.

  9. #9
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    I realise now you were talking insert type,
    However the Bokum I mentioned should cut either way.

  10. #10

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