Monosteel Blade Confusion

Discussion in 'The Kitchen Knife' started by musicman980, Jul 9, 2018.

Help Support Kitchen Knife Forums by donating:

  1. Jul 9, 2018 #1

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    I'm a little confused on monosteel blades. I hear monosteel hitachi steels are too fragile and need to be honyaki to be usable. I also see other knives that are monosteel carbon knives and are not honyaki. So first, why do mono hitachi carbon steels need the honyaki treatment and others do not, and second, can a monosteel AEB-L 5mm thick mioroshi deba be possible without softening the spine?
     
    Last edited: Jul 9, 2018
  2. Jul 9, 2018 #2

    RDalman

    RDalman

    RDalman

    Senior Member

    Joined:
    Mar 30, 2015
    Messages:
    1,489
    monosteel whichever Can be made just fine without honyaki process, without softening spine too. IF heat treated and tempered properly (not just a forge flash temper, that style of making might warrant honyaki process yes). I mean a "modern" accurate heat treat, with a tested formula.
    Aeb-l doesn't exist in 5 mm. but i think 13c26 does, and it would work well for that purpose I think :)
     
  3. Jul 9, 2018 #3

    HRC_64

    HRC_64

    HRC_64

    Senior Member

    Joined:
    Aug 9, 2017
    Messages:
    2,583
    Suisin Inox Honyaki, which I believe a variant of 19c27 @ ~61 HRC,
    is, despite the name, a uniform-hardness sweedish stainless series.

    They make a (pricey) 240mm x miorishi deba, see below link
    http://www.korin.com/HSU-IHYMI-240

    edit: the suisin alloy corrected for typo
     
    Last edited: Jul 9, 2018
  4. Jul 9, 2018 #4

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    A place near my hometown has AEB-L up to .195" inch thick 4' x 2" billets that I was thinking about turning into a mioroshi. Is the catch that it can't be super high hardness? Removing the heads from fish is a demanding task, but a monosteel non-honyaki carbon or AEB-L could handle it if properly or thoroughly heat treated?
     
  5. Jul 9, 2018 #5

    bahamaroot

    bahamaroot

    bahamaroot

    Senior Member

    Joined:
    Jan 14, 2013
    Messages:
    1,582
    Where did you hear this? It's BS.
     
  6. Jul 9, 2018 #6

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Isn't one of the benefits of a soft cladding added strength?
     
  7. Jul 9, 2018 #7

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Less likely to break
     
  8. Jul 9, 2018 #8

    Bensbites

    Bensbites

    Bensbites

    Senior Member

    Joined:
    Feb 21, 2017
    Messages:
    570
    I have looked into AEB-L a little, I am pretty sure something like 60 HRC from a professional HT service is about where you want to be. The pros might know more and can correct me.
     
  9. Jul 9, 2018 #9

    bahamaroot

    bahamaroot

    bahamaroot

    Senior Member

    Joined:
    Jan 14, 2013
    Messages:
    1,582
    Yes but that doesn't imply that monosteel knives can't be done.
     
  10. Jul 9, 2018 #10

    RDalman

    RDalman

    RDalman

    Senior Member

    Joined:
    Mar 30, 2015
    Messages:
    1,489
    I think suisin uses 13c26 (sandvik)
    Aeb-l is made by uddeholm-böhler (here in sweden munkfors, I buy directly from them) and the thickest it's made in is 3,5mm. So if someone is selling it thicker ask to see the certificate or get a copy, my bet is it's 13c26 (not that there's any big differences between them but you should get the right info)
     
  11. Jul 9, 2018 #11

    S-Line

    S-Line

    S-Line

    Well-Known Member

    Joined:
    Jun 16, 2015
    Messages:
    204
    I think Suisin is Sandvik 19c27
     
  12. Jul 9, 2018 #12

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Oh I'm aware that monosteel knives are made, I was just under the impression that a monosteel non honyaki hitachi steel knife would be a little too brittle for the average user. Does one exist?
     
  13. Jul 9, 2018 #13

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Ah thank you for this info, whenever I'm home next I'll have to check that out.
     
  14. Jul 9, 2018 #14
  15. Jul 9, 2018 #15

    Interapid101

    Interapid101

    Interapid101

    Well-Known Member

    Joined:
    Sep 19, 2017
    Messages:
    243
    Masamoto KS also.

    I'd like Larrin or another expert to comment, but heat treat can't really be defined as "proper" or "thorough." There are optimized heat treat parameters for a given steel, but whatever protocol is optimal for that given steel will also depend on the target hardness/toughness.
     
  16. Jul 9, 2018 #16

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
  17. Jul 9, 2018 #17

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    The benefit of honyaki is added strength right?
     
  18. Jul 9, 2018 #18
    If you want the edge to be HRC 64-65, you either use san mai construction or you differentially harden the blade (honyaki). Considering the failure rate of honyaki blades when they are quenched, most smiths use the technique that produces the highest yield if they are not selling to the high-end market.
     
  19. Jul 9, 2018 #19

    Interapid101

    Interapid101

    Interapid101

    Well-Known Member

    Joined:
    Sep 19, 2017
    Messages:
    243
    Strength is not exactly a descriptive term here. Toughness is appropriate. Honyaki knives should have enhanced toughness in the spine and tang. In some cases the honyaki process may also allow a maker to bring the edge to a higher hardness (but likely less toughness) than they would have done otherwise.
     
  20. Jul 9, 2018 #20
    No, the benefit of honyaki is a higher HRC edge without compromising the toughness.
     
  21. Jul 9, 2018 #21

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Sorry, just for clarification. The benefit of honyaki is not that strength/toughness is added, but that toughness does not go down when heat treating a monosteel blade to high HRC?
     
  22. Jul 9, 2018 #22

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Meaning a honyaki 64 HRC is stronger/tougher than a regular monosteel 64 HRC, all other conditions being the same?
     
  23. Jul 9, 2018 #23

    HRC_64

    HRC_64

    HRC_64

    Senior Member

    Joined:
    Aug 9, 2017
    Messages:
    2,583
    Thanks for the correction, I've edited the post above
     
  24. Jul 10, 2018 #24

    chinacats

    chinacats

    chinacats

    Senior Member

    Joined:
    Mar 20, 2012
    Messages:
    6,974
    Thank you!
     
  25. Jul 10, 2018 #25

    XooMG

    XooMG

    XooMG

    Senior Member

    Joined:
    May 23, 2013
    Messages:
    1,855
    Many of the benefits of laminates are in workability. Forging, grinding, bending, polishing. A lot of user maintenance with simple equipment is easier too. Primary "strength" benefit is in limiting propagation of failures like chipping.

    Monosteel works fine.
     
  26. Jul 10, 2018 #26

    BloodrootLS

    BloodrootLS

    BloodrootLS

    Well-Known Member

    Joined:
    Oct 18, 2012
    Messages:
    136
    First of all, strength is not similar to toughness and they can even be inversely related in some situations.

    Secondly, honyaki blades are not necessarily tougher/less likely to "break" than monosteel, and actually I would say in general, because of the way they are heat treated and tempered they are often less "functionally" tough than the majority of monosteel blades heat treated at the same high hardness that are heat treated with temperature controlled equipment. Honyaki blades have an area of the spine that is unhardened steel. This would likely stop a crack from propagating if the crack reaches that area of the blade. Of course, if this happens the blade is already completely ruined. Knives break near the edge or at the tip in 99% of the cases and the toughness of the spine rarely matters for the end user (it does matter for the knife maker during manufacture). Carbon steel at HRC 64-65 is quite tough unless heat treated in a way that compromises toughness and at most blade cross-sectional geometries, the toughness of the spine is a moot point. From my understanding the main reason the spine is left unhardened on honyaki blades is A- because it's difficult to do, is traditional, and looks pretty, and B- because it allows some straightening of the blade during manufacture if it warps.

    Also, there is another way to toughen the spine of the knife than the "honyaki" approach that make the spine even tougher than the unhardened steel of the honyaki method and also preserves resilience and rigidity. Differential tempering.

    Additionally, knives without either kind of softened spine can be excellent top-shelf knives- everything depends on the intended use, geometry, alloy, and heat treatment.

    In my mind it is not very productive to oversimplify the effects of the basic knife blade constructions. Great knives can be made all of these ways.

    ~Luke
     
  27. Jul 10, 2018 #27

    BloodrootLS

    BloodrootLS

    BloodrootLS

    Well-Known Member

    Joined:
    Oct 18, 2012
    Messages:
    136
    +1
     
  28. Jul 10, 2018 #28

    musicman980

    musicman980

    musicman980

    Well-Known Member

    Joined:
    Nov 25, 2016
    Messages:
    138
    Wow this really clears a lot up, thank you everyone. I just read a bit on the defining terms of knife blade construction, including technically what "toughness" means and so on, I guess I'll have to watch out how I use layman terminology.

    So to wrap this up and around to the intent of my original post: Considering the intended use of the blade, is it generally advised to build a deba knife with something other than monosteel construction? Or can it fulfill all of its deba duties if the mono (AEB-L) steel has low hardness and high toughness? I just don't want it to snap and chip, guys, that's all.

    I hope that's not another ignorant question.
     
  29. Jul 10, 2018 #29

    Kippington

    Kippington

    Kippington

    A small green parrot Hobbyist Craftsman

    Joined:
    Jan 13, 2015
    Messages:
    1,143
    Location:
    Melb, Australia
    Here's the thing: 'Chipping' and 'snapping' could be considered two very different modes of failure.

    To simplify things, take a look at chipping of this kind:
    [​IMG]
    This happens to be a san-mai blade with tougher steel cladding... but the important thing is this: The chip happened beyond the reach of any tougher steel which could've prevented it from happening.
    So it wouldn't make any difference if this was mono-steel, san-mai or honyaki. This chip-out has nothing to do with any of that and only depends on the heat treatment, the bevel angles (or steel thickness near the edge) and the way the knife was used.

    On the other hand, the following picture is a totally different thing. Is this what you're worried about?
    [​IMG]
    Both san-mai and honyaki style construction could help prevent this kind of thing from happening, as the cracks would have to propagate through the tougher steel. But there are other reasons this happens too, and a well constructed mono-steel blade shouldn't have this happen either, as others have mentioned above.
     
    Last edited: Jul 11, 2018
  30. Jul 10, 2018 #30

    Larrin

    Larrin

    Larrin

    Senior Member

    Joined:
    Mar 13, 2011
    Messages:
    620
    Toughness is most likely to be important with kitchen knives in terms of chipping of edges or breaking off tips, neither of which is affected by lamination. The laminated sides are usually softer, or less strong, not stronger. So if you tried to break the entire knife in half it would definitely change its properties there.
     

Draft saved Draft deleted

Share This Page

Group Builder