Chisel Grind...Why?

Discussion in 'General Knife Discussion' started by d762nato, Jan 6, 2016.

  1. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    Actually, these friends are knife nuts who just happen to be doctors. One of them is actually a knife maker. They can handle the questions, trust me. ;) :thumbup:
     
  2. EChoil

    EChoil Banned BANNED

    May 22, 2014
    My God, record them....or get 'em ON here.
     
  3. chuxwan

    chuxwan

    423
    Aug 26, 2012
    The only (inherent) difference between two zero ground FFG blades with the same inclusive angle, one chisel and one v grind, is the orientation of the edge to the spine/axis of the tool handle (as fortytwoblades has already explained). If you still think these grinds are very different, then you're grouping in a whole bunch of other givens based on your own misunderstanding of the terms...
     
  4. EChoil

    EChoil Banned BANNED

    May 22, 2014
    Continue my education here....how can a a chisel and a v-grind have the same inclusive angle? In fact, how does a chisel have an inclusive angle at all?

    Of course the orientation of the edge to the spine in both will be different. They're different grinds.

    Am I misunderstanding you here?
     
  5. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    The one difference is that if producing the knife by stock removal the pivot of the chisel example would cause the far edge of the spine to rotate outside the bounds of the base stock, reducing the effective stock thickness. However, because increased proximity to the edge increases the magnitude of influence of the specific geometry on cutting performance, the only significant difference you'd see (unless the blade was really narrow) would be a reduction in rigidity.
     
  6. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    Easy, man. Two knives, with a 30° included angle, but one is symmetrically ground and the other is chisel ground. The former is 15° per side, while the other is 0° on one face and 30° on the other.
     
  7. EChoil

    EChoil Banned BANNED

    May 22, 2014
    OK. Just never used the term "inclusive" for the angle on a FFG chisel grind. To me "inclusive" implies two bevels in existence. Guess you could call one a zero, yeah.

    But the principle remains, doesn't it, that if you have a 30-degree inclusive V-grind and a 15-degree chisel....isn't the chisel going to cut better with only half the edge angle and resistance (geometry again) of the V-grind? I thought that was one of the principles that makes a chisel theoretically desirable to some.

    Too much theory?
     
  8. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    That's the problem--edge angle must be held constant to have any basis of comparison. Otherwise you're just saying a thinner edge cuts better, which isn't dependent on it being a chisel grind vs. a symmetric or even an asymmetric double-beveled grind.
     
  9. EChoil

    EChoil Banned BANNED

    May 22, 2014
    Got it.
     
  10. JParanee

    JParanee Gold Member Gold Member

    Dec 23, 2006
    I've been using chisel grinds for 30 years and they cut just fine :)
     
  11. whateatsrabbits

    whateatsrabbits

    Nov 24, 2011
    The edge angle is constant 15 dps. Not the chisels fault it only has one side. I think we can all agree a chisel grind lends itself to thinner geometry
     
  12. stabman

    stabman Gold Member Gold Member

    Sep 17, 2007
    No, we cannot agree on that.
    Did you miss that my Emerson knives are the same thickness at the same spots regardless of chisel or V-grind, and the same stock thickness?
    The grind starts as far back on them too.

    Grinding it thinner lends itself to thinner geometry, that's the fact of it.
     
  13. Skimo

    Skimo

    Mar 28, 2009
    You miss the fact that the angle is referenced, for V grinds the reference is the center of the spine. For a flat grind with a chisel grind it is referenced from the side of the spine.

    15 degrees on any knife is 15 degrees.
     
  14. EChoil

    EChoil Banned BANNED

    May 22, 2014
    Are you trying to say, with all things being relative and both blades having equally thick spines, a chisel ground will still make a sharper, better cutting, whatever (geometry) knife out of a thicker (i.e. stronger) blade? Due to having half the angle.....
     
  15. Lycosa

    Lycosa

    Aug 24, 2007
    So, the V and chisel grinds are the SAME?
     
  16. 22-rimfire

    22-rimfire Gold Member Gold Member

    Nov 20, 2005
    I have to say that it is clear as mud in terms of theoretical cutting ability between the two grinds. To my knowledge, the only chisel grind knife I own is a Razel and it is especially good for scraping.
     
  17. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    No. No it isn't. The constant is 30° included angle, or the total edge angle. If you want to use 15° then the double beveled grind would be 7.5° per side. You'd be talking straight razor or scythe angles at that low, so if you tried actually using a chisel grind that low it'd be subject to a lot of rolling.
     
  18. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    You're confusing the degrees per side with the included angle, or the total angle of the the edge, and it this angle that is held constant--not the degrees per side.
     
  19. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    They have never once seen a chisel-ground scalpel blade. Also, apparently, in the professional vernacular it's something of a faux-pas to call them a scalpel. They refer to them as a knife or a blade. Good to know I guess.
     
  20. EChoil

    EChoil Banned BANNED

    May 22, 2014
    Amazing. Are these guys specialists by chance? It's hard to find anything authoritative on the www regarding the question...overall whether most "scalpels" are chisel ground...

    I'd still say there's a chance that higher--end doctors are probably exposed to higher--end equipment (which I would certainly cede such V-ground scalpels would be considered higher--end) vs., say, third world tent clinics by the thousands, and various lower--tier mass medical operations in the world.

    And I'm not meaning to belabor anything here. It just seemed to me that scalpels might have relevance or cover one aspect of the thread topic.

    I sure may be wrong, but it's something I've always noticed and often heard. I think at this point it's only you and I who cared anyway.....
     

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