Production M390 - Expectation vs Reality?

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

  1. shunsui

    shunsui Gold Member Gold Member

    Aug 12, 2008
    I can help with some of that. Here the url to a pdf download.
    Common Problems in Rockwell Hardness Testing
    by Doug McGhee (he works for NewAge Testing Instruments)
    In Heat Treating Progress May/June 2004 (a trade publication)
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  2. shunsui

    shunsui Gold Member Gold Member

    Aug 12, 2008
    Someone posted this before, but it was from a different source and rendered very slowly for some reason (for me). This copy is a very good pdf.
    It's old, 2001, but gives you an idea of what's what. The sharp eyed reader will notice Doug McGhee's name on the Acknowledgements page.

    NIST Recommended Practice Guide
    Special Publication 960-5
    Rockwell Hardness Measurement of Metallic Materials.

    You might need to paste the url into your browser's address line.
    Last edited: Jul 3, 2019
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  3. danbot

    danbot Gold Member Gold Member

    Oct 31, 2009
    So, basically this is all the result of good intentions + "amateur hour".
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  4. Banter 247

    Banter 247

    Feb 22, 2019
    Amateur hour in terms of how the Dom was handled with regard to verification + reporting, yes. Not in terms of testing.

    Let’s recall...

    1. Brad is a lead with Peters HT Blade division. Brad verified Kurt’s methodology, and confirmed the equipment, maintenance, and calibration standards used by Kurt to be good.

    2. Brad tested the TRE and Manix, himself, verifying Kurt’s results on those.

    3. Brad’s tests on the Dom did not match Kurt’s previous hits on it.

    If it’s true that one difference -> Kurt is an amateur, then it calls into question Brad/Peters, not to mention previous third party verification from Manly and Tuya, among others.

    Does it seem more likely that the outlier is a one off, or that all of the other verification indicates that these people are all wrong?
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  5. Banter 247

    Banter 247

    Feb 22, 2019
    This is the piece causing my reply to the quote to take so long. Instead of burning a week writing a reply about the idea of M390 optimized for cutlery at 57hrc, I’m going to refer you to Larrin’s articles at
  6. Mo2


    Apr 8, 2016
    • Warning for trolling 20 points for a year
    He left out info to make Kurt look bad on purpose in this situation. That's wrong and if I get points so should he. After all Kurt's a member here and this is a vendor making things up about him that he can't even prove. He makes the assumption that he said bad things and deleted his account because of that, with no proof to back that up. Why even say that? Then goes on to try and ruin his reputation with his government contracts must be getting the wrong data but left out the info that Banter already mentioned.

    So again. I'm not off base here.
    David Richardson likes this.
  7. shunsui

    shunsui Gold Member Gold Member

    Aug 12, 2008
    Sounds like a one off to me. I've been impressed with Kurt's measurements on the various Spyderco knives. The numbers match up to values reported in the past for those steels. Especially impressive with that old Wilson tester with it's two month calibration cycle. Apparently with some knives, some disassembly is required.
  8. Banter 247

    Banter 247

    Feb 22, 2019
    Indeed. The anvil used can help with many (not all) samples regarding finding a suitable location without disassembly. This has been why we’ve sometimes heard people say “you can’t do that without taking the knife apart.” Without something like this:


    ... they are correct. Even with that, as you say, some need to come apart.
  9. David Richardson

    David Richardson

    Nov 30, 2018
    That's a good doc. It doesn't tell us what state Kurt's machine was in or what protocols he followed. Somebody else with good credentials seems to have validated that Kurt knows what he's doing and has good equipment.

    Thanks for summarizing what we know and don't know. Without more analysis and perhaps more testing we can't know why there was a discrepancy. I don't think it says anything about Kurt or Brad.

    Maybe, maybe not. Let's not assume and try to speak to the facts we know rather than filling in the gaps with speculation. I hope we get an explanation for the discrepancy in the future. We may not. For now I'm going to continue to use the BladeBanter data and assume the tests Kurt did on my knifes are accurate.
  10. David Richardson

    David Richardson

    Nov 30, 2018
    Some may want to disassemble so the testing mark is hidden by the frame/scales.
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  11. skyhorse

    skyhorse Gold Member Gold Member

    Jan 30, 2010
    If you really want to fact check Rockwell hardness numbers it should be done by Peters. Imho you're dealing with something way out of your league , causing a lot of grief for people and putting their livelihood in jeopardy.
    Yo Mama likes this.
  12. redw0lf


    Jun 27, 2019
    This was a fantastic thread and situation in terms of learning and shit happens. One we can all progress from.
    However not without some slight damage, I will use myself as an example..

    I stumbled upon this thread while researching the Lionsteel M4.. I was ready to buy a new fixed blade and I was interested in the m390 .. I almost pulled the trigger, till I started following this..

    Even after recent events, I am still reluctant to try m390, and its a shame, because I really fell for this blade the last few weeks.

    I decided a bark river 3v blade would be more of a "safe buy" .. I just can't bring my self to gamble on the LS M4 even if recent news shows there may be no gamble.. but I suppose thats my problem..

    It was interesting however how my mind set changed, and how Im now scared to buy the blade I really wanted. I am sure I will like the barkriver and forget all about it.

    Shit happens though.
  13. orangejoe35

    orangejoe35 The Opposite Gold Member

    Nov 23, 2016
    I'm familiar with the articles. I think I've read all of them. Here's a lot of explaining to convey an idea that probably doesn't matter anyway.

    I have a Kershaw Link, made in USA in M390. It costs $80. I don't know the hardness of the knife, but according to The Spreadsheet, it's probably around 59. According to Blade HQ, there are USA-made Kershaws available in 14C28N, CPM-154, 420HC, Damascus, S30V, CTS-BDZ1, D2, and M390. According to the data sheets from Bohler, Crucible, Carpenter Tool Steel, Sandvik, and Latrobe, cryogenic treatments are optional for all of those steels except Damascus (which I didn't look up) and 420HC (whose data sheet didn't mention cryogenic treatment). All of the hardness values in The Spreadsheet for USA-made Kershaws could be achieved with or without cryogenic treatment. I don't know if Kershaw has the capacity to cryogenically treat their knives.

    I think it's possible that Kershaw doesn't cryogenically treat anything. So, if Bohler gives them two heat treatment options and you don't want to fund Kershaw's cryogenic expenses, then you pay for the heat treatment without subzero treatment. At $80, I don't think I paid for very much extra from Kershaw. I'm aware that more optimal hardnesses exist, but maybe not with this heat treatment. I have no idea what Kershaw does or doesn't do with their steels, I just had the Link in my pocket and used it as an example.
  14. Banter 247

    Banter 247

    Feb 22, 2019
    Allow me to say, again, that I suggested in-group that results of low outliers be third party verified and reported privately to companies. This was then agreed upon by all involved, and is part of why you hear that language repeated in LTK’s video.
    David Richardson likes this.
  15. knifeswapper

    knifeswapper Knife Peddler Dealer / Materials Provider

    Sep 3, 2004
    Back a few posts there was a response to Mo2 that included some rebut of nearly every point he made. I can add some clarity to those as well.

    False: First post was Mike insinuating that they did an hrc test on the blade edge. Of which wasn't true.
    True: If you read the referenced post, you will understand that I am referring to knives that I sent to Peters previously - not those that Kurt took. My post was well before Kurt even went to Peters.

    False: The 2nd to last paragraph in particular in the latest post are a bit disingenious. Saying he would have to hunt down posts. And then next calling out one comment about paint chips, which is in reference to running the test.
    True: Already addressed by someone that read my statement without preconceptions; but just to verify: There were many vicious trolls on instagram that attacked anyone requesting a measured testing methodology or questioning the process used. Many of the trolls prompted responses by those on the testing team, to include Kurt, that made some statements in hindsight seem ill advised. So, it would be much easier to just remove the account than to hunt them down. But this was speculation on my part, I don't know why he removed the IG account. But in one particularly vicious attack by trolls on a customer of mine that only recommended third party verification, I copy/pasted the entire exchange and that is where I quoted Kurt's response to the care that need be taken with equipment that will be used to make commercial claims.

    False: It's not hard, many knife makers get an aim's Hardness tester and read the directions. You don't need to be an expert to run an hrc test.
    True: It's not hard to test for private use. But when you are going to test to call a manufacture incompetent or challenge their specifications, you probably need to do more than read a manual. For example, documents are found rather easily that say never test within 3 diameters of another test / edge / anomaly. Yet you can clearly see the shuffler has been tested at least twice within 3 diameters of another test.

    False: If Mike was at Peter's, he would have known that they compared methods of running the test and calibration with Peter's and nothing is different in the methods. Not to mention they tested other knives that got the same results with on both machines. But Mike wouldn't know that, cause he wasn't there.
    True: I wasn't there. But I am the one that introduced Kurt and Brad. I am the one that setup the verification with an agreement that I would be provided the results pertinent to the knives which I was invested. My conversation with Brad does not reconcile with your statement. First off, there is no way that any shop's testing / calibration methods compare with Brad's. Every morning at open they test a NIST 30, 40, 50, and 6X (don't recall if it was 61, etc.) block 3 times on each of their 3 machines. That is 36 tests just to open the shop each day. Calibration is done at any time these do not provide expected results, but never any later than the industry standard calibration dates (calibration is done by a 3rd party).
    It is expected that they would match on some results. Sadly very few testing methodologies allow for "a finite number of unexplained inconsistencies".
    I have had several long conversations with Brad. He is the most detailed and genuine person I have ever talked to in this expertise. For example, on their testing equipment it takes 8/10000ths of inch of to drop the hrc result by 1 point. Thus by my calculation that means a 50micron particle of dust would provide a reading up to 3 points off. When that type of precision is required, I want someone doing more that just buying themselves a tester and reading the manual (as is suggested) if they were going to challenge commercial results.

    False: Yet Mike's making it seem like this anomaly makes all these tests invalid, of which does not. Then he goes and says how his work place must have all the wrong numbers...
    True: No, quite the opposite. I think most of the results were probably correct. But it is a science, and especially when you are going to go after a companies livelihood with commercial claims. They had readings that any industry expert could spot as highly questionable. For example, I asked Brad how likely it was to get 4-6 different readings on 1 square inch of a blade tang. His response was that in 36 years he has never seen a variance of more than a point or two inside that amount of space. There can be false low numbers for many reasons - false high numbers are an entirely different issue. Once that shuffler received a 58 test, a big red light should have started flashing. Any testing methodology that is going to expect the respect of the industry is going to need to be easily reproducible by peer testing experts. And if you are putting out even one number that is proven patently incorrect - then the entire methodology has to be re-evaluated.

    Opinion: Besides all of this, it's just two knives. Ignorant people blew it out of proportion based off of what someone like Ltk said in his video. Of which is apparently corrected and he's apologized.
    Differing Opinion: To LTK is was just two knives. To me it was the total sum of EVERY knife from my modern traditional series that EVER tested outside of factory specifications. We wasted many blades testing to try and find the anomaly. But the only two we had ever seen tested low were by one person.
    I think anyone that saw the videos knows it was more than a passing mention. It was the poster boys of the pitch that was being sold. LTK kept adding to his original mention with statements like he would "stand on" these results. When what I said about "headaches" was interpreted to be a legal threat, he said "bring it on". Now, he is a good guy and comments look much different in hindsight many times than they do at the point in time where you are certain that you are right. But I will point out that in his "giveaway" video, that was posted Saturday after Kurt had retested the dom himself to within specs and then taken to Peters and got four identical readings of 59.1hrc, he doubled down on the old readings but started broadening the conversation away from simple hrc readings that had been the backbone of all previous videos. Making no mention of any updates to include new readings. That was when I was compelled to make my first post since the ill advised post on the original video.

    Regarding the comment about taking a blade out of the frame for testing. That was mentioned in my response to the first youtube video wherein I was discussing the knives I had sent for testing. Those knives also included a sample from the "Bolus" series which does not have nearly as much tang exposed. Brad called me to ask if he could remove it from the frame to insure a valid test. I am in no position to question him on this point.

    I think Lee and Kurt are good people. I don't think they set out to have this thing blossom like it did. But there was not enough management of the situation to insure it would not turn out like it did. Lee is very "excitable" in his videos. And he drew a large crowd of folks that had no concern for what the publicity would do to the other folks involved. I did not go on a witch hunt. I kept my mouth shut for two weeks while the facts came out and only when it appeared as if those known results were not going to be offered by the testing team - I responded with a differing view on a more neutral youtube channel.

    Before moving back to Oklahoma to help my parents after a terminal diagnosis for my father, I had a highly technical career. Which also included working with / for government contractors. My background and my mindset is analytical. Thus I see things differently than many. But, although I love to have conversations with the members on BF as well as other platforms - I hate controversy. Many times I play the devil's advocate and many times there are disagreements. But many times these controversy come up on social media that would never have come up with folks having a civilized conversation face to face.

    There is no way for me to express how much this situation has stressed me over the last couple weeks. But to be honest, in the last week we have had personal events that leave it nearly just banter. Not that the stress has resided any, but that I never realized how much stress a person would have to endure sometimes in God's path for us. I know when you put yourself into the public eye, you open yourself up to being called a liar, a crook, etc. etc. But I would simply ask, for me, and recommend for everyone else reading - just take the time to approach a person like you would your neighbor at the picket fence on these kinds of issues. There are so many things that unite us and so few that divide us.
    Last edited: Jul 3, 2019
  16. Boru13

    Boru13 Super Moderator Staff Member Super Mod Moderator

    Apr 25, 2000
    Good luck with that.
  17. redw0lf


    Jun 27, 2019
    Sarcasm? Are they also not great?
  18. halden.doerge

    halden.doerge I'll Sharpen Your Knife Gold Member

    Aug 17, 2014
    Dude. Digging in wasn’t a great look when this thread started, and it’s getting worse by the minute.
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  19. Boru13

    Boru13 Super Moderator Staff Member Super Mod Moderator

    Apr 25, 2000
    Not sarcasm, you might wanna do a little research on that though before claiming a "safe buy".
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  20. Insipid Moniker

    Insipid Moniker

    Feb 28, 2011
    Some of them aren't even 3V.
    bikerector, willc, jux t and 2 others like this.

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