10V or K390 for corrosion?

Discussion in 'Spyderco' started by TRfromMT, Aug 28, 2020.

  1. TRfromMT

    TRfromMT Gold Member Gold Member Basic Member

    Jan 4, 2016
    Is either one any better at corrosion resistance?

    My previous favorite tool steel is M4, and where I live it is actually ok for corrosion resistance, with nothing more than a nice patina.

    My K390 actually shows corrosion.

    How does 10V hold up? More like K390 or even marginally better?
  2. bdmicarta

    bdmicarta Gold Member Gold Member

    Feb 16, 2012
    I thought 10V and K390 had virtual identical metallurgy.

    I've liked M4 for a long time and I don't have a problem with corrosion in general use, but my one knife that I use when working in the yard and so forth will surface rust quickly if I carry it in the summer when I'm sweating a lot. It's not a serious problem for me, I just wipe it off and go on.

    I'm going to try Rex45 for awhile to replace M4.
  3. TRfromMT

    TRfromMT Gold Member Gold Member Basic Member

    Jan 4, 2016
    Virtually, but not exactly. One or two trace elements are different, and who knows what kind of ground up unicorn horn in one or the other. I saw some endurance cut test comparisons by a YouTube reviewer and 10V did just a bet better (both Spydie PM2 knives). So is am wondering if one or the other has even a little better corrosion resistance.

    I like all aspects of K390 over M4... except the corrosion aspect.
  4. Mark Spark

    Mark Spark

    Jun 1, 2020
    I have a PM2 in K390 and a Gail Bradley folder 2 in M4. To me K390 is better for corrosion. That's because it takes a beautiful silver blueish brown patina from 45 minutes in apple cider vinegar. After that, no rust ever. M4, however, won't take a patina for me, but does get black spots no matter how much you try to keep it clear. It naturally darkens in a less attractive way.
    TRfromMT likes this.
  5. TRfromMT

    TRfromMT Gold Member Gold Member Basic Member

    Jan 4, 2016
    Maybe a forced patina on the K390 is the way to go.
  6. Twindog

    Twindog Gold Member Gold Member

    Apr 6, 2004
    Both 10V and K390 will tarnish. They are very similar steels. According to Knife Steel Nerds, "Bohler released K390 around 2004 [6], which modified 10V to have higher Mo plus W and Co additions."

    M4 is even worse for me here in the rainforest because it pits when it rusts, which is an awful characteristic.

    10V should have a tiny bit more wear resistance, and K390 should be a bit tougher.

    If you need super wear resistance and stainless, you could go with S110V or S90V.
    MolokaiRider and John_0917 like this.
  7. anycal


    Jan 11, 2017
    I like non-stainless steel. I don't coat my blades in any kind of oil, but I do try to keep them clean.

    I think the texture of the blade finish has something to do with how it will corrode/patina. From my experience, smoother finish will patina easier.

    The smooth finish of the PM2 K390 looks very similar to my Native M4. And they both developed a deeper, darker patina.

    The coarser PM2 10V is similar in texture to couple of my other M4 and REX45 blades. Similar patina, but far less than the smoother blades.

    TRfromMT likes this.
  8. TRfromMT

    TRfromMT Gold Member Gold Member Basic Member

    Jan 4, 2016
    @Twindog I hear you - m4 pits. I was just wondering about the possible difference between the 10V and K390 specifically. I really like the way K390 sharpens. Conversely I'm not a fan of high/hard stainless steels for sharpening. Don't know why.
  9. The Mastiff

    The Mastiff Gold Member Gold Member

    Apr 21, 2006
    Both are going to be pretty similar. Heat treats and more importantly the steel finish will decide which does better. in other words if one had a mirror finish ( unlikely because of the wear resistance making it expensive) and the other a stonewash the mirror will do better. They are both better than a simple carbon steel like 1095 but either one is far from corrosion resistant. I use wax on mine and they pretty much doesn't have any issues. Both are excellent knife steels!

  10. 3fifty7

    3fifty7 Gold Member Gold Member

    Dec 24, 2016
    I can’t speak to K390 but I find 10V to be lacking in the corrosion resistance department.
  11. Bapple


    Feb 1, 2010
    The 10V Para 2 is also available in coated blade if you are worried about corrosion
    TRfromMT likes this.
  12. John_0917

    John_0917 Gold Member Gold Member

    Apr 15, 2014
    It only has 4% Cr so ...

    K390 has a little more Cr but still well below stainless (or semi), the cobalt may help somewhat also, which 10V does not have.
    TRfromMT likes this.

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