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Benchmade 3v

Discussion in 'General Knife Discussion' started by Mo2, May 14, 2019.

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  1. H0kieengineer

    H0kieengineer Gold Member Gold Member

    339
    Jun 24, 2017
    It’s hard to describe without showing the whole testing process but basically the indented has to travel through the coating and the steel, which gives a longer travel distance and a lower measured HRC. Rockwell tests measure hardness indirectly by directly measuring how far a specifically shaped indented travels into a test specimen.
     
    steff27 and marrenmiller like this.
  2. Alchemy1

    Alchemy1 Gold Member Gold Member

    905
    Dec 31, 2011
     
  3. AF

    AF Gold Member Gold Member

    Jan 14, 2000
    I wonder what hrc Cold Steel targets for 3V.
     
    jux t and Mo2 like this.
  4. dano

    dano

    Oct 3, 1998
    Curious how an Internet forum seems to attempt a redesign and re-engineer a model, based on what, exactly?
     
  5. Twindog

    Twindog Gold Member Gold Member

    Apr 6, 2004
    Surface preparation-related causes

    Rough surfaces cause rough results. If you’re only interested in knowing roughly how hard a part is, a rough surface will work. But if you’re inter- ested in accurate, consistent test re- sults, always test a shiny surface. Even though the Rockwell method begins its hardness measurement beneath the surface of the part, the inherent vari- ability of a rough surface can and will cause inconsistent results.

    Surface coatings or hardened layers also can provide deceptive results. If you want to test the hardness of a coating or surface layer, use a load/indenter combination that will ensure that the measurement is taken in the coating or layer. Remember the 10X rule: the thickness of a part or coating must be 10X greater than the maximum depth of penetration. On the other hand, if you are interested only in the hardness of the substrate and not that of the coating, the coating or surface layer must be removed using a suitable surface preparation technique.
    https://www.asminternational.org/do...416b-8f06-4ac5-8511-244aa5fc54c0/HTP00403P023
     
  6. Alchemy1

    Alchemy1 Gold Member Gold Member

    905
    Dec 31, 2011
    I didn’t bring this over here. I simply posed a scenario that @Benchmade still refuses to answer and I do say refuse. I have a screenshot where whoever is in charge of their account admits that they’re aware of this conversation and they’re going to respond, but that was hours ago. Interesting isn’t it...hmmmm
     
    mdrgn79 likes this.
  7. Silent H

    Silent H Gold Member Gold Member

    352
    Feb 1, 2018
    I doubt their social media person is an engineer, or was even involved with the design. It actually makes me feel better that they're (hopefully) taking the time to get a proper answer from someone with design and metallurgy knowledge, rather than just telling you "that's the way it is" and dismissing your evidence.

    If they don't answer you soon, that might be more of a problem.
     
  8. Mitchell Knives

    Mitchell Knives Knifemaker Moderator

    May 21, 2000
    56 HRC is laughable.

    They likely left it this soft to make the manufacturing process easier.
     
    Steel-Jaws, fq55, willc and 3 others like this.
  9. Alchemy1

    Alchemy1 Gold Member Gold Member

    905
    Dec 31, 2011
    Anybody that knows business or customer service knows that you at least keep the person busy while you figure out a solution. Even if you just say, “wait here while I get my boss”. The message also literally says that THAT person is about to comment. We need to stop making excuses for companies. It’s sad and only hurts us, the consumer.
     
  10. Mo2

    Mo2

    Apr 8, 2016
    They probably got to wait for Stacked to get back to them.

    Here's some science lol
     
  11. jux t

    jux t Gold Member Gold Member

    500
    Jan 10, 2018
    On the master hunter 3V, it's either 61 or 62.
     
    Mo2 and AF like this.
  12. marrenmiller

    marrenmiller Basic Member Basic Member

    985
    Apr 6, 2017
    As noted above, hardness testing works by measuring the depth of a dent made in the material when pressed upon with a specific tool with a calibrated force. If you put cerakote on something, which can be .001"-.002" thick (cerakote is extremely thick for a coating), then you would get an inflated depth of indentation, which would indicate a lower hardness. The depth of deformation is already extremely minimal, so this makes a noticable difference. This wouldn't matter so much if the coating was DLC (which is substantially thinner), but since cerakote is so thick it probably threw the values off.
     
  13. DeadboxHero

    DeadboxHero Triple B Handmade Knives, Big Brown Bear

    Mar 22, 2014
    I've been sharing in the Instagram discussion.

    [​IMG]

    This is how the test works. The red feature in the picture is a 120° diamond conical penetrator. It is first set at the minor load with 10kp or Kiliograms of force shown as "F1" than given the the major load "F2" 140kp and held for a moment before releasing back to 10kp. The permanent deformity in depth is measured as "e" in mm gives you the Rockwell hardness test scale c.


    This is the formula

    [​IMG]


    The dial of the machine goes to 100 HRC and is subtracted from the mm of permanent deformity "e" over 0.002mm which is increments of measurement used by the instrument.

    So let's say that the Benchmade is within the advertised 57-59 rc at 57.5rc.

    That would be 0.085mm of permanent deformity for 57.5 HRC

    0.085÷0.002
    = 42.5
    100-42.5
    =57.5HRC

    Now if the cerakote is 0.001" thick that would be 0.0254mm

    Given the hardness of cerakote, it may not be affected the 10kg of force from the preload but would most definitely be smushed by the 140kg of force from the main load.

    That would add additional depth to the permanent deformity measurement in mm.

    0.0254mm + 0.085mm
    =0.08754mm
    0.08754÷0.002mm
    =43.67
    100-43.77
    =56.23HRC
     
    steff27, tomhosang, austonh and 9 others like this.
  14. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    I would think a rockwell test would be done before any blade coating was applied ?
     
  15. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    I've always assumed testing was done on blades prior to any coating process ?
     
  16. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    The HRC testing is normally done before finishing process such as blade coatings at Buck and I don't think a coating would affect the hardness of the metal it's applied to.
     
  17. DeadboxHero

    DeadboxHero Triple B Handmade Knives, Big Brown Bear

    Mar 22, 2014
    You're missing the point here.
    The Benchmade was hardness tested by another person. Not Benchmade.
     
    steff27 and marrenmiller like this.
  18. marrenmiller

    marrenmiller Basic Member Basic Member

    985
    Apr 6, 2017
    If it was performed by benchmade, which it wasn't. This is someone else doing the test on a coated blade.
     
  19. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    My point is a blade coating shouldn't affect the hardness of unlaying steel. If Benchmade does a lousy job on their heat treat the coating won't change that.
     
  20. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    Whoever tested that blade should know to get a correct outcome it needs to be done on bare clean steel .
     
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