Production M390 - Expectation vs Reality?

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

  1. orangejoe35

    orangejoe35 The Opposite

    Nov 23, 2016
    Comment removed.
    Last edited: Jul 2, 2019
  2. PirateSeulb


    Jun 6, 2017
    I think LTK and hopefully any others involved have learned to be more cautious about releasing their data and particularly data that is so far out of spec. I hope they continue their work with a focus on being more thorough and reserved about releasing information to ensure that it can be a genuine tool for the community and the makers alike.
  3. miso2

    miso2 Gold Member Gold Member

    Nov 19, 2014

    I agree that their intention was/is good and beneficial for us knife nuts, and appreciate it.

    To me, it is common sense and rationale to conclude that a clean environment would be desired for accurate and consistent measurement based on the fact that it depends on very precise depth measurement.
    But it is just me.

    We know that the tester(s) has gotten and may get outliers or inconsistent values but don't know the probability and cause for improvement.
    So it is not wise to take individual measurements seriously, whether they are good (right on or high) or bad (low), for them and for us.
    One PM2 specimen has been mentioned to have 62 HRc and a good one, but it may very well be an outlier.

    Based on the measurement error and variability, I think that multiple measurements on different samples are required for statistical inference, not anecdotal survey.

    Just my 2 cents.

    Edit: I guess large manufacturers have group data already. I wish they release the mean values and SD or CV, not just a range (like PM2 60 +- 2 HRc).
    Last edited: Jul 2, 2019
  4. Banter 247

    Banter 247

    Feb 22, 2019
    That PM2 appears to not be an outlier. Alchemy1 and Kurt confirmed this morning that one of the new Delicas in M390 hit at 62, as well.

    As for third party verification... Kurt has been verified many times over, including the trip to Peters. The Dom stands alone. To that end, everyone is now on board with verifying low outliers before reporting, and reporting privately first.
  5. miso2

    miso2 Gold Member Gold Member

    Nov 19, 2014
    First off, I do appreciate what you guys are doing for the community (assuming that you are part of it, as Blade Banter?).

    I was just saying that I do not know how certain I can be about individual values.

    To me, it would be beneficial to aggregate data on a single steel from a single manufacturer with an assumption that they equally heat-treat the steel and aim at a hardness value.
    For example, you guys have 5 data points on M390 from Spyderco including the Delica you mentioned (59.6, 59.2, 60.1, 62.0, and 62.0).
    We do need more samples for sure but let me assume that they follow a Gaussian-like distribution of (mean 60.6, SD 1.3), including sample variability and measurement errors.
    Then, we can compute the probability of having a value below 58 HRc and get 0.027.
    So we would get 2 ~ 3 blades out of 100 below 58 HRc measurement (by Kurt).
  6. Banter 247

    Banter 247

    Feb 22, 2019
    Makes sense. Each hit is just a data point of one, rather than a predictor of everything from a model or batch, as you say. The biggest value of a second 62 hit for Spyderco M390 is that a high outlier vs a low aimed range would be very, very unlikely. This at least indicates that the aimed range includes 62, and that makes it likely that the aimed range is 60-62, assuming a spread of 3. While not a certainty, it’s the most likely range which includes 62.

    That is a lovely thing to find.

    As for my involvement— Bladebanter is a different person. I am a part of the group involved in various ways with the doc. Things have evolved unofficially such that I’ve been the voice on the forums (here and others), while Kurt does hrc testing, Supersteel Steve and Outpost76 do edge retention testing, InthePocket and Alchemy1 do result reporting, Bladebanter maintains the doc, and I’ve also added topical videos about related concepts along the way. LTK was mostly independent (interacting with Bladebanter/David and Kurt) until very recently, but we’ve set up a second chat stream to help with communication. Again, none of the above was predetermined, it has just kind of developed that way. The situation around the Dom has necessarily lead to more cohesion and guidelines.
    miso2 likes this.
  7. knifeswapper

    knifeswapper Knife Peddler Dealer / Materials Provider

    Sep 3, 2004
    I didn't see this post until just now as my we have been involved in a devastating family event. And reading 20 pages would probably just aggravate me terribly. But I would like to offer this right here and in the other nasty thread - if you have a question about anything I said on social media about this particular discussion regarding its authenticity or truthfulness, post it right here and tag me. Not a nasty accusatory post, but a question of explanation in a courteous fashion - I will explain in kind.
    attila., willc, jux t and 14 others like this.
  8. MolokaiRider

    MolokaiRider Gold Member Gold Member

    Sep 13, 2017
    Sorry to hear about this. Smoke sent to you and your family.

    Equally sorry about all the un-needed overly dramatic content about all this.
    91bravo, knifeswapper and ScooterG like this.
  9. Banter 247

    Banter 247

    Feb 22, 2019
    I’m the only person active in the conversation at this time who has involvement with the group doing testing, and I’m the person who suggested third party verification and private reporting to manufacturers, within the group. I’ve previously linked your comment on Nick’s video and confirmed your account of the Lionsteel hits in this thread.

    Everything should be peaches & cream.

    Feel free to reach out if needed.
    cistercian and knifeswapper like this.
  10. palonej

    palonej Platinum Member Platinum Member

    Aug 5, 2015
    Smoke up from the Northeast for your family Mike.
    Prayers sent also.
  11. miso2

    miso2 Gold Member Gold Member

    Nov 19, 2014
    To me, your statement was clear and understandable.
    LTK has published an apology to you and Lionsteel for his actions on this.
    I think the case is settled now and we learnt a lesson.
    The only thing I have a gripe about you is that I cannot buy Otnat directly from CK as being outside the US :)
    knifeswapper likes this.
  12. bikerector

    bikerector KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Nov 16, 2016
    I've been known to be a go-between for some international folks, if you're hard set on that knife. Slippies are usually easy to ship as well. If you ever need amother person to be a knufe purchasing enabler:D
    palonej, MolokaiRider and miso2 like this.
  13. Danke42


    Feb 10, 2015
    I was in the same boat as you when the first shuffler run came out and one of the regulars got one for me and shipped it up to Canada. It just took a few days more than buying direct.
  14. knarfeng

    knarfeng senex morosus moderator Staff Member Super Mod Moderator

    Jul 30, 2006
    Let me take that apart line by line.
    He did not insinuate anything. He stated that there is not a good flat spot on that blade to test. Peters confirmed that THEY had to take the knife apart to find a suitable spot on the blade. I have tested knife blades and have run into similar issues. It's a valid observation, not an "insinuation". Strike one.

    You misread his statement. He said Kurt deleted his Instagram account and stated that it's easier to delete an account than to hunt down posts in which Kurt had made unwise remarks. Strike two.

    He said nothing of the sort. He only talked about LTK's failure to state that third party testing by Peters did not confirm his earlier findings. Strike three.

    There is nothing in your other post which validates the venom in the post you posted in this thread. If you do it again, you will be warned with points.
  15. Banter 247

    Banter 247

    Feb 22, 2019
    Not disputing the rest, and only pulled this piece out to clarify.

    Brad (of Peters) and Kurt actually confirmed/matched the samples taken, other than the Dom.

    The Dom is the only one relevant to CK’s involvement, which makes it easily understandable why that was the focus of his statement.

    The TRE and Manix Brad and Kurt tested together lined up with Kurt’s previous hits.
  16. knarfeng

    knarfeng senex morosus moderator Staff Member Super Mod Moderator

    Jul 30, 2006
    Exactly. Mike was only addressing the LionSteel knife because those are HIS. Special factory order. He is the only seller.

    I can well understand Mike's Ire. I did not hear anything in LTK's non-apology to acknowledge that his trumpeted findings on the CK LionSteel knife were not validated by third party testing. Mike was significantly more polite than I would have been under similar circumstances.
  17. Banter 247

    Banter 247

    Feb 22, 2019
    In light of Mike’s position, I think he handled it better than anyone could reasonably expect.
  18. orangejoe35

    orangejoe35 The Opposite

    Nov 23, 2016
    I think maybe some of the companies are using this heat treatment,
    and some are using the heat treatment below.
    That would mean that some knives are optimized at a lower HRC. Maybe, at your price, 57 is optimized. Maybe you don't want to pay to get a higher HRC at the cost of price and corrosion resistance. I think maybe everything's okay.
  19. Banter 247

    Banter 247

    Feb 22, 2019
    Edit: I misread the quoted post initially, and will revisit.
    orangejoe35 likes this.
  20. Banter 247

    Banter 247

    Feb 22, 2019
    Edit: revisiting.

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