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High rc steels and performance cutting

Discussion in 'General Knife Discussion' started by Robert Carter, Oct 15, 2012.

  1. Robert Carter

    Robert Carter

    Sep 26, 2011
    I've lately being doing a lot of research on higher rc steel 62+. I just wanted some opinions of what would be the ideal steel for high performance cutting as well as edge retention.

    I have been working with s30v s35vn and cpm d2. They are great steels, but I'm looking for high performance on a competition level.

    I guess what I'm asking is what combination of high rc steel and types of grinds should I be considering for my next batch of user knives to produce a wicked slicing machine with incredible edge retention. In other words it just has to cut extremely well and carry an edge for a long time as well as descent wear residence.

    Considering cpm m4 as one of my next steels to try.

    Thanks for time and input
  2. Mikael W

    Mikael W Platinum Member Platinum Member

    Apr 21, 2007
    I think the convex geometry found on Opinels together with powdersteels in the 62rc region, will be close to Your aimed goal.

    Provided the heat-treat and geometry are right for the steel, the result should meet Your expectations.

    Personally I prefer a thicker cuttingedge more oriented towards allround cutting, as I also cut in hard and abrasive materials.(I'm a self-employed Carpenter and carry knives 24/7.)


  3. singularity35


    Mar 1, 2010
    What about cpm-10v, K294, or K390? I assume it's not going to be a chopper.
  4. marthinus


    Dec 10, 2006
    I think you should contact Phil Wilson. He has done some impressive work with high wear steels at high hardness.

    I have seen CPM-M4 taken up to 67 HRC and the maker feels it is one of the best working steels available.
  5. Robert Carter

    Robert Carter

    Sep 26, 2011
    I have been considering cpm-m4 for a while just have so many orders coming in I havnt had a chance to get back to work on it.

    I will be trying to make a light weight liner lock or frame lock mid sized folder with a 8 inch or 3 inch convex chisel grind to offer edc use. Something simple and affordable for those looking for a knife that just cuts. Knives are cutting tools, why not make one that does the job extremely well.

    So cpm-m4 is on the list. 10v is another hopeful.
  6. james terrio

    james terrio Sharpest Knife in the Light Socket Moderator

    Apr 15, 2010
    CPM-154 has become almost passe', but it's still an awfully good steel. Crucible's data sheet shows achievable hardness up to 64Rc, but they recommend it at 62Rc max. I've been running it at 58-59Rc for general purpose knives and I like the balance of toughness, edge retention and relative ease of sharpening, but I think it would be worth a try at 62 for a nice thin slicer.

    CPM-3V is one of my favorites, with outstanding toughness and very good edge retention. Long a popular choice for choppers and combat/survival stuff at 58-59Rc, it's often overlooked for smaller knives. But it's pretty dang good in light thin blades at up to 62Rc.

    CPM-M4 seems to be pretty much king among competition cutters these days. I'm not certain what Rc most of those guys are running it at. I haven't used any yet, partly because it's crazy expensive, and partly because I just have other fish to fry right now.

    Elmax is great stuff, too, and little less expensive - if you can get your hands on some. I've made a few blades with it and really like it. In CATRA tests, Elmax @ 62Rc actually beat M4 @ 61Rc for pure edge retention. M390 beat them both.

    Here is a short article by Phil Wilson comparing Elmax, K294, M390 and N690.

    This is Bohler's HT data on some of their steels.
  7. Ankerson

    Ankerson Gold Member Gold Member

    Nov 2, 2002
    CPM 10V, K294 (A11) can be taken to 64-65 HRC and has a very high compression strength so it can be taken to a very thin edge.

    For stainless CPM S110V can be taken to the 64 HRC range.

    Links of K294 and CPM S110V at high hardness tests.



    Test of the Spyderco South Fork in CPM S90V:


    M390 (61 HRC) vs CPM S90V (60 HRC) shootout:


    A11 (10V, K294) is very fine grained, can be taken down to a very thin grind, is a very aggressive cutter and will take a highly refined edge if needed and will just keep cutting for it seems forever. They make commercial cutters out of A11 if that tells one anything about the extreme wear resistance of this excellent grade.

    CPM S110V is a very high alloy stainless that is very fine grained, will take a highly refined thin edge and IMO is the best stainless that is available right now.

    M390 is an excellent steel that is very clean and will perform excellent at high hardness in the 61-62+ range.

    CPM S90V is high wear steel that fine grained and will take a high refined edge, best at 60+ HRC.

    Any of these steels will perform at a very high level with very thin ground edges as they are at the top of the food chain for wear resistance.

    Other notable steels are CPM 154 (62 HRC), ELMAX (62 HRC), CTS 20CP, CTS XHP, Duratech 20CV and CTS 204P.
    Last edited: Oct 15, 2012
  8. knives emporium

    knives emporium Banned BANNED

    Jul 13, 2012

    For high a high Rc this would be one that I would consider ZDP-189; Cowry X has about the same metallurgical composition, nevertheless it’s harder to come by and is more expensive. Both super steels behave like a charm in the high Rockwell department.

    ZDP-189 - Powdered steel with uniform and fine microstructure
    - Chemical Composition : Fe - 3%C - 20%Cr
    - Excellent wear resistance due to high hardness (66 to 68 HRC)
    - Good toughness against chipping
    - Good corrosion resistance

  9. Robert Carter

    Robert Carter

    Sep 26, 2011
    A wealth of great information thanks guys. Soon as I am able to get back on this prodject (which maybe a while) ill most certainly start a thread with my finding on several different steels at various high Rocwell points. Also include HT methods with each, although I will be following suppliers recommended heat treat for exact rc points. Also possibly find someone here on the forums that won't charge me to much to rc test a few a blades. My next batch of steels will be cpm m4, m390 and cpm-10v. Again it may take me a while due work and orders but ill get to it soon as I can.
  10. Ankerson

    Ankerson Gold Member Gold Member

    Nov 2, 2002

    CPM M4 should be in the 64 HRC range, M390 in the 62 HRC range, CPM 10V in the 63-64 HRC range, all Cyro treated also, that's if you are going to grind them really thin for extreme performance. :)

    Might want to shoot Phil Wilson an email on these steels also. :)
    Last edited: Oct 15, 2012
  11. The Mastiff

    The Mastiff

    Apr 21, 2006
    CPM M4

    All can easily do rc 64-65 with a temper. Jim above has some good suggestions.

    For stainless Rc 63+


    Rc 62+

    CTS 75

    Rc 62


    All these are conservative numbers and the steels can be pushed a bit higher. Your call naturally but some of them might get chippy if pushed. Some won't yet and have more to give ( M2, M3, M4, S110V, etc.)

    ZDP 189 pretty much stands alone at Rc 66-67 ( except for Rex 121, etc, which I don't consider suitable for cutlery steel)

  12. Ankerson

    Ankerson Gold Member Gold Member

    Nov 2, 2002

    ZDP-189 is for the most part all Chromium Carbides, with the HT and tempering to get it to that high hardness the trade off is less stain resistance.

    It is a good steel though, used mostly in Kitchen knives.
  13. Robert Carter

    Robert Carter

    Sep 26, 2011
    Any makers here can do rc testing for me? Pm me
  14. james terrio

    james terrio Sharpest Knife in the Light Socket Moderator

    Apr 15, 2010
    If no one steps up... I have most of my HT done by Peter's and they Rc test each blade. I don't know if they would just do Rc testing on some blades for you, you'd have to call and ask. Ask for Brad Stallsmith and tell him I said howdy. :)
  15. The Mastiff

    The Mastiff

    Apr 21, 2006
    I agree Jim. It won't be at the peak of any results listings taking wear resistance, or toughness into consideration but it can run as easily at rc 65 as many can do at rc 59.

    If I was going to run it at rc 67, just as with any steel run at max hardness I'd likely try to heat treat each blade separately, one at a time.
  16. Ankerson

    Ankerson Gold Member Gold Member

    Nov 2, 2002
    Yep, very true Joe. :)
  17. Robert Carter

    Robert Carter

    Sep 26, 2011
    Thanks James I may just send out for the heat treat on these that way there are less variables and more consistency
  18. Ankerson

    Ankerson Gold Member Gold Member

    Nov 2, 2002
    If you are grinding the blades really thin behind the edge the hardness really needs to be dead on for sure. :)
  19. Robert Carter

    Robert Carter

    Sep 26, 2011
    I couldn't agree more. No reason to conduct a study half ass*d. I've got a lot of plans, just little time.
  20. Ankerson

    Ankerson Gold Member Gold Member

    Nov 2, 2002
    Yes, lots of testing at different hardness to see what works the best for sure, also different thickness to see what the best balance would be for what you want the knives to do.

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