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Ken Onion knife sharpener

Discussion in 'Carothers Performance Knives' started by gunslinger387, Dec 7, 2018.

  1. gunslinger387

    gunslinger387 Basic Member Basic Member

    Aug 31, 2010
    I only have two CPK’s, a Behemoth Chopper and HDFK. These knives are wicked sharp! I want to keep them that way and not change a thing. Can anyone tell me what angle they are sharpened too?


    gusbuster likes this.
  2. Hard Knocks

    Hard Knocks Gold Member Gold Member

    Oct 1, 2012
    Welcome to the forum, and congratulations on landing two beautiful blades. I don't know that info off the top of my head but @Nathan the Machinist will. There is also an 'ask Nathan a question' thread HERE.


    Odog27, gusbuster and Choppaman like this.
  3. Wood5045

    Wood5045 Gold Member Gold Member

    Feb 22, 2016
    My notes show both are sharpened to 20 degrees.
    Hard Knocks, Odog27 and gusbuster like this.
  4. untytled

    untytled Gold Member Gold Member

    Feb 21, 2014
    @gunslinger387 Hey Kevin this is what I gathered from old sales threads

    Edc 18 dps
    Field knife 15-18 I've seen both
    Hdfk aka NASK 20 dps
    Light chopper 20 dps
    Medium chopper 20 dps
    Heavy chopper 20 dps
    Behemoth chopper 20 dps
  5. untytled

    untytled Gold Member Gold Member

    Feb 21, 2014
    Some more info:

    So your answer is 20 ;)
    - SpyderMan - and Odog27 like this.
  6. gunslinger387

    gunslinger387 Basic Member Basic Member

    Aug 31, 2010
    Thank you
  7. bluemax_1

    bluemax_1 Gold Member Gold Member

    Jan 17, 2014
    You might've missed the 'sharpening a CPK' thread, but you might not want to use the Worksharp on a CPK. Distinct possibility of overheating the very edge, potentially messing up the heat treat.
    CataD and untytled like this.
  8. gunslinger387

    gunslinger387 Basic Member Basic Member

    Aug 31, 2010
    Bluemax 1, good looking out. I’ve never had a problem with it causing a blade to heat up. A few smooth easy passes on each side works well and doesn’t even get warm. I think they might be referring to larger commercial grade stuff.
  9. bluemax_1

    bluemax_1 Gold Member Gold Member

    Jan 17, 2014
    Might want to try searching for Nathan's post about using any type of belt sander style sharpener.

    He specifically mentions that it's very easy to overheat the extreme edge while sharpening it, because by the very nature of a razor edge, there's very little material there.

    The mass of the blade absorbs and dissipates the heat so the blade doesn't seem to 'feel' warm, but it's enough to negatively affect the heat treat at the very edge, that gives D3V the edge retention it's known for.

    I happen to have that exact model (got it when there was some ridiculous sale on it), but I've never used it. I'll probably post it up for sale somewhere else.

    Here's the thread, referencing another belt type sharpening system, with Nathan's posts.

    For reference, that sharpener in the thread, that Nathan says can potentially affect the D3V heat treat, runs at 1000+SFM, IIRC. The Ken Onion Worksharp is variable from 1200 to 2800 SFM
    Last edited: Dec 16, 2018
    gunslinger387, Hard Knocks and CataD like this.
  10. Nathan the Machinist

    Nathan the Machinist KnifeMaker / Machinist / Evil Genius Moderator Knifemaker / Craftsman / Service Provider

    Feb 13, 2007
    Our powered grinder here that we use for sharpening is also adjustable. We typically adjust between 150 and 300 sfm, and use flood coolant.
  11. UffDa

    UffDa Gold Member Gold Member

    Sep 11, 1999
    I have seen many new custom knives with areas on the edge that are blue. That is a good sign that the edge was over heated. I have read complaints about new knives that did not hold an edge until they have been sharpened a few times by hand. Again, that is a good indication that they were sharpened on a belt sander and the edge was overheated.

    Just IMHO, of course and we all know what pinions are. ;)
    gunslinger387 likes this.
  12. cold one

    cold one Gold Member Gold Member

    Jul 23, 2009
    Interesting, I thought the Ken Onion Work Sharp was actually a lower speed then most belt sharpeners but 1200 sfm minimum is way faster than 150-300 sfm.
  13. Casinostocks

    Casinostocks Factotum Platinum Member

    Mar 20, 2016
    Yes, a small gear or spindle engaging with a larger one.
  14. UffDa

    UffDa Gold Member Gold Member

    Sep 11, 1999

    The Work Sharp is nothing more than a small belt sander, isn't it? Keep in mind that most people who buy things like that have no idea what they are doing and don't really care very much. If they did, they would learn to sharpen by hand. Again, just IMHO.

    I have a couple of pull through sharpeners that I have tried over the years. One has diamond plates that don't work very well. The other has small ceramic wheels. That one puts a ragged edge on kitchen knives that cut pretty well, but I don't use either of them. I find that my ceramic "steel" and an occasional touch up on a DMT plate works just fine.

    There are also many guided sharpening systems like Edge Pro and Lansky that seem to work OK. (I have never used one.)
    duramax likes this.
  15. cold one

    cold one Gold Member Gold Member

    Jul 23, 2009
    I use the worksharp from time to time on my knives, mainly Becker and Busse, when they need a serious sharpening and it does fine, otherwise I use strops to maintain them.
    Only have had to strop my CPK knives so far, guess I will keep the worksharp away from them and just hand sharpen.
    ilyk likes this.
  16. bluemax_1

    bluemax_1 Gold Member Gold Member

    Jan 17, 2014
    Yeah, the reason I never used the KE Work Sharp after getting one a couple of years ago, was the concern about how much metal it might remove quickly, and the potential for affecting the heat treat.

    I'm glad I saw Nathan's post in the other thread, as it detailed the specifics in a way I hadn't considered.

    The thing is, these types of tools CAN get knives really sharp. The issue is how long it will stay sharp, if you've negatively affected the heat treat of that very fine edge.

    Just using it and saying, "Well, it gets my knife razor/shaving sharp", is completely missing what Nate's talking about. The whole point of the D3V protocol, is to produce an optimal blend of toughness and edge retention, which folks who've used these knives hard, for extended periods can attest to.

    I have other knives that sharpen easily, and I can get them shaving/hair popping sharp fairly quickly. They don't tend to stay super sharp for very long.

    I wouldn't want to chance screwing up whatever it is that Nate's metallurgy testing/magic does, to make CPK's D3V stay sharp the way it does, and his post in the thread I linked to, indicates how easy it might be to affect the heat treat with one of these belt sander type sharpeners.
    Hard Knocks and untytled like this.
  17. UffDa

    UffDa Gold Member Gold Member

    Sep 11, 1999
    People are going to do what they want to do regardless of informed advice. I have seen nice Randalls and other expensive knives that have been sharpened (?) on bench grinders. Once the knife belongs to you, you can ruin it to your heart's content.

    I once complained to customer who wanted us to ship his mint Swedish M38 to a custom gun smith to have it turned into a sporter. He told me that it was his gun and if he wanted to toss it in the street and run over it with his truck, that was his right.
    Last edited: Dec 17, 2018
  18. bluemax_1

    bluemax_1 Gold Member Gold Member

    Jan 17, 2014
    While all of this is absolutely true, the difference is wrt 'informed'.

    Oftentimes, folks do, or don't do certain things, simply because they don't know any better.

    There's a difference between, "After reading Nathan's post about the mass at the very fine edge, vs mass behind the edge, I now understand how it may be possible to overheat the extreme edge without realizing it"


    "I know, and I don't care. The edge retention that CPK is known for, doesn't matter to me. I'll do what I want".
    CataD likes this.
  19. UffDa

    UffDa Gold Member Gold Member

    Sep 11, 1999

    That was the point I was trying to make. I was making a general statement, not pointing a finger at anyone.
    duramax and stjones like this.
  20. indawire

    indawire Gold Member Gold Member

    Dec 26, 2011
    Thanks for the 20/ dps angle info. I've been waiting for Christmas to open the box with the HDFK in it, it's my big present to myself this year. Not that I expect to have to sharpen it for a while but now I know what angle to.

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