Super Hard (70 Rc) High Speed Steels – Maxamet, Rex 121, and More Explained

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Larrin, Dec 2, 2019.

  1. Thomas Linton

    Thomas Linton

    Jun 16, 2003
    They retain desired properties when they get hot from high speed use - a property useless in knives used in the hand.
     
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  2. Richard Coyle

    Richard Coyle Gold Member Gold Member

    38
    Nov 12, 2019
    Ohh ok thanks!
     
  3. Willie71

    Willie71 Warren J. Krywko. Part Time Knifemaker Knifemaker / Craftsman / Service Provider

    Feb 23, 2013
    I killed a bandsaw blade cutting annealed Rex121.
     
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  4. shqxk

    shqxk

    Mar 26, 2012
    In my experience 52100 and W2 hold an edge better than 440c. I know 440c has more Cr carbide which would contribute greater wear resistance but I believe finer grain structure, higher toughness/hardness of W2/52100 can lead to better edge retention overall?
     
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  5. DevinT

    DevinT KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jan 29, 2010
    Ha-ha

    Hoss
     
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  6. DevinT

    DevinT KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jan 29, 2010
    Sure, 440C will be more wear resistant than 52100 if hardness geometry and sharpening are the same and we are talking slice cutting.
    52100 will out cut 440c at higher hardness, more acute sharpening, and with push cutting.

    Hoss
     
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  7. tim37a

    tim37a

    945
    May 18, 2010
    Sorry, Natlek but Hoss has probably forgotten more about knife making than you will ever know.
     
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  8. DeadboxHero

    DeadboxHero

    Mar 22, 2014
    I love Rex 121, Just wish It loved me back :p
    [​IMG]
    Very painful to make knives out of.

    Hardest, most wear resistant steel I've used.
    Beat Maxamet at 70rc and 15V at 67rc in cut testing 3/4 rope by a good margin so I'll keep suffering, stuff works great for advanced users.

    Hardest Steel I ever tested was this piece of Rex121 at 71rc

    [​IMG]
     
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  9. DeadboxHero

    DeadboxHero

    Mar 22, 2014
    It really depends on how and what you're sharpening with and what media you're testing with and how.

    For me Rex 121 stayed the sharpest a(200g BESS) after cutting a 100 pieces of 3/4 Manilla rope with 8 slices each cut with the least amount of weight possible to slice.

    The simple carbon steels wore smooth around 30-50 cuts in other tests.

    The rope is to simulate animal hide although the hide and fur can be a lot more abrasive.

    Wayne originated the test, Maynard Meadows improved it and Phil taught me his way he learned from them and further modified. I Run a simliar test but I just run to 100 and see what is sharper at the end and look at the rate of dulling using these tools.



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    Last edited: Dec 3, 2019
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  10. Natlek

    Natlek

    Jun 9, 2015
    And if I do that you will say that it is not valid and you will find million reason for that .......? Why not other way ? Show me the proof that I m wrong ?
     
  11. Natlek

    Natlek

    Jun 9, 2015
    That is good idea but no . I don t see any reason to put him on ignore :D
     
  12. Natlek

    Natlek

    Jun 9, 2015
    May I add ......................It is difficult to heat treat them in , you know what :)
     
  13. Natlek

    Natlek

    Jun 9, 2015
    Maybe.........but probably I spend more time outdoor then he spend in his shop making knives.....
    If there is steel I know it is 440C..........I used it and see used by many here all my life .
     
  14. Natlek

    Natlek

    Jun 9, 2015
    Did you read my post ? That Catra test data is almost of no use to us .They test edge geometry not steel .What I say is that with same geometry 440C vs HSS , when 440c will lose it s WORKNIG sharpness will get real dull very fast .With HSS that will not happen , HSS will stay in that working sharpness for loooong time .........
     
  15. Natlek

    Natlek

    Jun 9, 2015
    Is this what Catra do ? They test different knives with different hardness , different geometry ? What use we have from data like that ? So IF 440C ..............and IF 52000 ......winner is WHO ?
     
  16. Larrin

    Larrin Gold Member Gold Member

    Jan 17, 2004
    Please stop making stuff up.
     
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  17. Natlek

    Natlek

    Jun 9, 2015
    Are we are on same page or it is my English again ?
    This is your words ...........
     
  18. Natlek

    Natlek

    Jun 9, 2015
    Do you ever used knife from HSS steel and which one is that ? I have maybe more then 50 of them right now and around 30 give to friends ..most of them are hunters .Some are from M series some from T series HSS steel...so I making stuff ?
     
  19. Larrin

    Larrin Gold Member Gold Member

    Jan 17, 2004
    I'm eagerly awaiting the side-by-side comparison the hunters made between 440C and high speed steel with controlled variables.
     
  20. Natlek

    Natlek

    Jun 9, 2015
    Controlled varibales........ that is what your father will say to me if I show how I do my test .............game which will proof nothing !
    Look , this is how I learn...................see this two blanks ? They are cut from same saw , edge of both was line between them before i cut them .So same hardness , same grain structure ................So I can play with geometry , final grit sharpening ...blabalabala and see by my self how that affect without worry about HT....Hrc...Grain ...etc . And that is best way to get some REAL data . If you know better way show me I and i will try that ..
    This is 3mm. thick M2 HSS
    [​IMG]
     
    Last edited: Dec 3, 2019

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