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Production M390 - Expectation vs Reality?

Discussion in 'General Knife Discussion' started by Cosmodragoon, Jun 11, 2019.

  1. David Richardson

    David Richardson Gold Member Gold Member

    217
    Nov 30, 2018
    Agree. My point is what's usable to me may be different for others. Some people can't sharpen or don't like sharpening harder steels. Some people only need to sharpen an EDC once a year. Just allowing for my preferences to not be the same as others'.
     
    Last edited: Jun 24, 2019
  2. Murphjd25

    Murphjd25 Gold Member Gold Member

    Apr 27, 2016
    I’m curious to see how the Hinderer 20CV is..
     
  3. Agith

    Agith Gold Member Gold Member

    333
    Nov 29, 2010
    I know that BHQ has a few 20cv knives listed as 60-61 HRC on their xm-24s, but that is really the only site I have found with any HRC specs for Hinderers and haven't seen much in the way of testing on his 20cv/M390

    [​IMG]
     
    Murphjd25 likes this.
  4. ShannonSteelLabs

    ShannonSteelLabs KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Sep 9, 2015
    That exactly why you push M390 to 60, 61 or higher. Will perform better than S30V.
    If you push the steel harder than 58 it will far outperform S30V. 60HRC should be the starting point. I reccomend 61-62. But if you can get higher with a stable heat treat then it will definitely outcut S30V.
     
    LX_Emergency, willc, Mo2 and 4 others like this.
  5. Lapedog

    Lapedog

    Dec 7, 2016
    Full disclosure; I’ve only read about half the thread so I’m not sure if this hasn’t been asked/addressed yet but:

    Doesn’t an HRC test measure the hardness of the actual steel matrix the carbides within the steel reside in? So while an s30v and an m390 blade both measuring 50 hrc is obviously not ideal; wouldn’t the 50hrc steel matrix of the m390 still hold more higher harness vanadium carbides within it?
     
    marrenmiller likes this.
  6. DeadboxHero

    DeadboxHero

    Mar 22, 2014
    No, they both have the same amount of Vanadium alloy%wt but M390 will have more carbide volume thanks to more Carbon and Chromium.


    *Where do these carbide volume numbers come from?

    @Larrin shared the calculated values using special thermal dynamic software that can calculate the carbide % volume made in a given alloy chemistry, the chemistry itself cannot tell you the totals but one can get a rough idea from some basic rules.


    Here are the calculated totals
    20% M390 total Carbide volume.
    14.5% S30V total Carbide volume.

    However, the bulk of M390's carbides are softer CrV7C3 (M7C3) Chromium carbides.
    17.5% Total

    With only 2.5% making the hardest VC (MC type) very fine, Vanadium Carbides.

    =20%total

    S30V on the other hand is 10.5% M7C3 and 4% MC type.

    =14.5% Total

    So while S30V has more of the harder Carbides, in this case, the higher volume would win in pure wear resistance on a industrial part being worn on abrasively. However if the S30v had higher hardness then tables may turn. Also a steel can have lower carbide volume but be more wear resistant thanks to having harder carbides. For instance, CPM 10v has a lower volume at 17.5% total carbide volume than M390 at 20% volume, but CPM 10v is completely (MC type) Vanadium Carbide with not enough chromium at high enough volume to rob the carbon and vanadium to make the softer M7C3 carbides like in M390.




    [​IMG]
     
    Last edited: Jun 24, 2019
  7. Officer's Match

    Officer's Match Gold Member Gold Member

    Jan 23, 2013
    My son bought a KW exclusive Contego in M390, which has been one of my favorite steels. He as not used it at all, and the blade now has severe chipping in numerous spots along the apex, as well as rust appearing on the edge. If he hadn't bought it new from KW, I would have for sure thought it to be a counterfeit.
     
  8. Banter 247

    Banter 247

    374
    Feb 22, 2019
    You are correct about hardness having to do with the matrix around the carbides. Softer matrix wears more quickly, and may release carbide more readily.

    Shawn’s breakdown illustrates why the *general* rule is that, within same composition, higher hardness -> higher wear resistance. Emphasis on *general*, because there are quirks like... D2 at 60hrc vs PSF27 at 59, where composition is the same, but the difference in process can overpower the difference in hardness.

    This is opposed to “higher hrc always -> higher wear resistance”, which is an occasionally misunderstood thing.
     
    ShannonSteelLabs and Mo2 like this.
  9. cistercian

    cistercian

    303
    Apr 22, 2015
    I have 2 710-1401's from them. They are beautiful until you look at the apex.
    They are serrated because the belt they used was so coarse...uneven too...
    Otherwise the blades are correct and symmetrically ground and the action is excellent.
    both are well centered as well. M390 and same black and blue G10 as the contego.
    I have not seen rust...but I oil everything.
     
  10. sharp_edge

    sharp_edge Gold Member Gold Member

    Jul 30, 2015
    I understand that much more knives in M390 are yet to be tested but based on the data by far, where does Benchmade's M390/20CV generally fall? Is M390 of Ritter grip better heat treated than say, the g10 20cv Griptilian? How is the M390 of Hogue Ritter compared to that of Benchmade Ritter?
     
  11. Officer's Match

    Officer's Match Gold Member Gold Member

    Jan 23, 2013
    This is not a ragged "toothy" edge - this is substantial missing material. The blade is toast AFAIC.
     
  12. Batmanacw

    Batmanacw

    16
    Mar 28, 2018
    I don't think there is more info than what is on the spreadsheet. I'm waiting on confirmation that the numbers on the chart are actually representative of the real story. Anyone who understands statistics knows a sample size of one is not a meaningful data set. We do not yet know how large a tolerance each manufacturer can maintain.

    Once we start to see multiple examples from each manufacturer will anyone be able to start making judgements that mean anything.
     
  13. Batmanacw

    Batmanacw

    16
    Mar 28, 2018
    What is the chance the blade is harder along the length than the thicker base of the blade? Could there be a difference?
     
  14. lambertiana

    lambertiana Gold Member Gold Member

    Jul 7, 2000
    The KW website lists the Hogue Ritter at 61-62. It would be interesting to see real test results. I'm holding out for a mini, but may spring for the full size if the mini does not appear.

    I'm also interested in seeing test results for Hinderer's 20CV.
     
  15. cistercian

    cistercian

    303
    Apr 22, 2015
    That is horrific...
     
  16. Banter 247

    Banter 247

    374
    Feb 22, 2019
    Alchemy1 has an RSK on its way for testing right now, iirc.
     
    Mo2 likes this.
  17. Banter 247

    Banter 247

    374
    Feb 22, 2019
    Very sensible. As with any testing, the best way to receive results is to note that unexpected results are just indications that it might be a good idea to look closer.

    This is a hot topic inside the group right now, actually. Over the past couple of days, it has been explored a bit. Hits on some samples have been inside .3 variance by location. Others, larger.
     
    AmosPaul likes this.
  18. Mo2

    Mo2

    Apr 8, 2016
    More data from RuslanKiyasov https://www.youtube.com/channel/UCkZ9ti9cI-RsaAcKIZB3kLA
    Some of his videos can be translated to English, but not a lot.

    *Note this is all rope cut testing, not cardboard testing. just another data point. rope is going to have different results than cardboard, or zip-ties, or carpet.

    *also note the benchmade AFCK is reground thinner. its a limited edition and some say its run higher hrc than normal, but it was not hrc tested here.

    *the geometry on the Cultrotechs is either zero or near zero grinds and high hrc.

    *also note the first screenshots are the number of cuts per 1cm of the working are of rope. the 2nd set of screenshots shows both that and the number of total cuts.

    m390

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]


    S30v

    [​IMG]
    bottom one is Shirogorov.

    more data from his spreadsheet
    https://kiyasov.com/youtube/results/
    Link: English translated

    this is his Link: testing methodology.

    These screenshots are sorted by steel name. descending in total number of cuts PER steel type.
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
     
    Last edited: Jun 25, 2019
    ScooterG likes this.
  19. DeadboxHero

    DeadboxHero

    Mar 22, 2014
    Ah, these are not zero ground.

    They are still much much thinner than any Production knife behind the edge though.

    At the shoulder of the bevel the Cultrotechs can measure between 0.2-0.3mm depending on model. Thats ~0.008"-0.012" bte. Most production stuff is 0.020"-0.025" bte that is fairly thick which reduces cutting performance for cost and durability.

    The edge angle on the Cultrotechs out of box can range from 18dps to 25dps depending on the customer and are all set with stones on fixed angle systems. So no burned edges


    Combine all that with them running the steels harder and with good HT help support the thinner Geometry and that's why they smoke a lot other knives in edge retention.

    The guys at Cultrotech are very dedicated, they will spend up to a week hand finishing a blade. They run steels like s125v and s110v up to 64-65rc. So it can be quite a challenge to finish so beautifully.

    So they are In the class of the Rocksteads and Shiros but use more wear resistant steels.

     
  20. ShannonSteelLabs

    ShannonSteelLabs KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Sep 9, 2015
    Exactly.
    I've seen some of the hand finishing they do. Absolutely gorgeous. It's even more awesome because the HRC numbers and level of finish they get.
    Some day I would love to get my hands on one. Just need to decide on a steel I want.
     
    Mo2 and DeadboxHero like this.

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