M390… Is it even steel?



This is without a doubt the most anticipated knife of 2012 for me. I’ve been eyeballing this knife for months and I’ve kept my eyes open for a good deal, but it seemed all these wonderful blue knives were priced at a ridiculous price, or simply sold before I got the chance to buy one.That was until 4 days ago when I saw one for sale and was able to buy it at the retail price. To say I was excited, is an understatement.

The fit and finish of the blade was excellent and the blade was perfectly centered and locked up perfectly. All in all, I was really excited to put the knife to use and test out the new M390 blade steel.


Here we go!


Out came the Edge Pro and the stones. I selected the following progression:


  • 140 Atoma Plate

  • 320 DMT plate

  • 220 Shapton Glass stone

  • 1k Chosera stone

  • 4k Glass stone

  • 8k Glass stone

  • 2µ CBN on horse leather

  • 1µ Boron carbide

  • 0.25µ Monocrystalline diamond spray (Hand American)


The reason I chose this was because I heard this steel was so abrasive resistant, most stones wouldn’t even cut it and if they did, they did it so slow it would drive you insane. I opted to set the bevel with diamond plates first so I could take out alle the uneven grind marks and reset the bevel completely before starting with the waterstones.

When I put the 140 Atoma on the blade and started sharpening, it SKIPPED. It didn’t plough through the steel like I’m used to, but needed some pressure to get it to bite through the steel. I was already impressed as I’ve never encountered something so abrasive resistant. The same applies for the 320 grit DMT plate. At this point I wasn’t really sure this stuff was even steel! It seemed unnatural to me and surely no human could have made this. It seemed as if my efforts would be futile, but persisted and got the bevel set after much hard work.


Here’s the edge of the 320 DMT (Burr wasn’t removed for this picture).

Now I started to doubt if anything would be able to tackle this steel, so I went back to the 220 GS to make sure everything was evened out. After 30 minutes of sharpening, I was satisfied with a 220 grit edge. Most of the time I’m done after 30 minutes of sharpening.


Here’s the 220 grit edge (deburred)

Now this is where the dilemma started. Icould go with 2 stones I saw suitable for the task. Both the 1k Chosera and Shapton pro were ready to tackle this beast of a folder and I had to make a decision. The Shapton would cut faster as it’s a bit coarser, but it would glaze and I would have to clean off the stone more often. The 1k Chosera is roughly the same as the 1500 Pro stone, so it would be slower at cutting the steel, but since it wouldn’t glaze, I chose this stone. i lapped it with a 140 grit Atoma plate and didn’t lap it any finer since the coarser stone finish would improve the cutting action. The result was almost 20 minutes on the 1k Chosera before I felt it I was done with it. the Hulk didn’t disappoint, it’s just the M390 that challenged it to the last minute. The result was a close to mirror finish from a 1k stone. That’s the power of the Hulk.

At this point I was so focused on the knife and the sharpening, i no longer went back to the microscope to take pictures. I felt it would take me out of the zone and would destroy my sharpening pleasure. It’s been a LONG time since a knife challenged me this hard to make a perfect edge.

The 4k Glass stone was my weapon of choice now. I knew the GS was fast and would cut very well, but the jump from the 1k Chosera might have been too much for it. because I ignored the 2k Shapton Pro it had a hard time removing all the 1k scratches. Next time I will include the 2k Shapton to make sure the scratches are gone. (Pretty much every other steel would be fine with a 1k Chosera to 4k GS jump). When I was done I could see the ridges of my fingerprints in the reflection of the edge.

I wasn’t going to make the same mistake twice and opted for a 8k GS instead of the Naniwa Snow White. While the Snow White is a very nice stone capable of some amazing work, I figured the GS would work faster and would compliment the 4k stone better. My intuition wasn’t wrong as I ended up with a perfect clear mirror and an edge that could push cut magazine paper an inch away from the holding point.

After this I refined the edge further with CBN, boron carbide and diamond sprays. I’m pretty sure refining it with something like CrO is an exercise in futility.

The result

I think my final edge is more than decent. I could have done better at the 1k – 4k gap, but overall, I’m pleased with my result. The fact that this steel held up to EVERYTHING I threw at it is impressive on it’s own. It polishes well, It is so abrasive resistant, that I wouldn’t even dare to reprofile it without diamonds and the final edge passed the HHT4. I think there’s not much more you can ask for in a knife steel.

30 thoughts on “M390… Is it even steel?

      1. I got an Paramilitary 2, as well bit it has S30V Steel?!?
        Why has your’s, another? Is it better or is it an older model and S30V is newer/better?

      2. It’s a sprint (prototype) run. These have very new steels and are designed to test steels. As I researched M390 a lot before Spyderco came out with this blade, I knew i HAD to get this knife.
        S30V is probably my most disliked steel as it hasn’t got a single field in which it excels.

      3. So what do you think is the best steel for getting a very sharp hair whittling edge? And what good knife featuring it do you know?

      4. A lot of steels can get hair whittling sharp, but the question is how long the steel will hold that edge. Modern “super steels” like ZDP 189, M390 ans S35VN hold that longer than any stainless I’ve tried so far. M4 does a really great job if you like carbon.
        You’ll find all these steels at Spyderco, some at Benchmade (but they are a tad softer)

  1. Nice! I’ve been using my M390 Ultimatum for a few weeks now and it’s still sharp (professional kitchen, used on the line). Part of me wants to see how long it takes to truly dull it but part of me wants to dive in and sharpen it. Right now that part of me is too lazy, though. 😉

    When I do sharpen it I’ll probably initially try the following: Atoma 140 > 1k GlassStone > 2k GlassStone > 4k GlassStone > 8k GlassStone > Roo’ leather > 1/8 mic CNB-on-balsa.

  2. Very impressive Michiel! I read you got it to HHT 4, but wouldn’t shave with it. So I assume you get it much sharper than S30V (which I hate too, at least in its ability to get it super-sharp). How does M390 compare to AEB-L (which is the stainless steel I can get the sharpest) in that respect?

    1. I finished on 0.25 diamond spray and that can often give a false positive in my opinion. It will pass the HHT just fine, but it will not be comfortable. That combined with a low angle could cause the edge to collapse in the middle of the shave. I sharpened it, and didn’t hone it without pressure so there is some edge deformation and micro chipping.

    2. It’s much more abrasive resistant than AEB-L, and the carbide are even fiber. A razor in this steel would take ages to hone, but one dialed in, it should last a LONG time. Overall, this steel has no match when it comes to stainless imo.

  3. Are the sigma power ceramic stones(namely the 1000-13000 kit) good for m390 (namely the rishmond 390 gyuto) suitable for sharpening this steel and sharpening a straight razor. I’m getting into this and straight razors at the same time and would like to kill two birds with one stone. Are there any cheaper alternatives and what would you recommend for finishing the straight razor, a strop or paddle or strop (I’m cheap and only want to buy what is needed, I’m not a collector).

    1. I have not tried the sigma’s on razor myself so I can’t comment on that. They will work on M390 and any other modern “super steel”. I like them when I tested them last year.

  4. I’m trying to decide on upgrading the mid-grit stones for my Edge Pro, but I don’t want to buy stones I don’t need. Did I read that right that you went from 220 to 1K?

  5. Dude I don’t know what M390 you sharpened but I did my 710 with m390 and it was not problem with shapton glass stones at all. Yeah it was a bit resistant to wear, but I found it no harder than s30v! Only took me about 24 mins to 35 mins to do the whole thing from scratch. The whole point of this steel is, its supposed to be grindable even though it is so abrasion resistant. That is why its so expensive! You spent how long setting your bevel with that 220?!?!?!? I set my bevel with my shapton glass 320, took about 10 minutes perside, and after that everything went pretty quick. I found it polished REALLY well too, so I only needed to take it up to shapton 4k to get a mirror polish.

    1. I’m getting a Benchmade in M390 in a few days. Remember this was a Colorado made spyderco and the out of the box edge was at 22 per side and the heel was even steeper. I reground it and matched the bevels with the coarse stones, then the polishing went quickly indeed. After that, sharpening it again was a breeze and it has rapidly become my favorite stainless steel.

  6. Is there a specific “type” of leather and compound you would most recommended for stropping?
    I just purchased a Benchmade Doug Ritter Griptilian, w/ a “stonewashed” M390 blade.
    I was wondering if the compound would mess with the finish? If so, what other medium would you recommend to use on the leather?



    1. I like horse leather the most. Roo is nice, but I still like the feedback from horse better.

      The compound would just be hitting the edge so it shouldn’t affect the finish at all. It doesn’t on my Ritter grip anyway.

  7. I can’t seem to be able to get a reply or see my post regarding how to go about doing this. What was used to grind initial angle? If anyone knows where to get started or can point me in the right direction about how to accomplish this please let me know!
    It’s confusing for the uninitiated to know where to start – I assume you can’t just put the same edge geometry or angle on every blade, and I also assume that you can’t do everything freehand so where do I start?

    1. To grindhe initial angle, I used an Atoma 140 plate on an Edge Pro Apex.
      You can do almost anything freehand, but using a guided system takes away the factor you have to learn how to hold an angle, so it’s quicker to learn.
      Putting the same angle on every knife is a bad idea as they will have different steels or purposes.

      1. Thanks for your reply. I have the same knife as shown in your tutorial (the valet). I also have a variety of angle grinders and systems – KME sharpeners are based bout 30 minutes from where I live and the owner gave me a full set of tools from one of their first products including some beautiful stones. Ron is a terrific guy! I also have a decent quality electric wheel (a Stanley) along with all sorts of attachments, but I still can’t find a definitive resource to explain how to determine which grind and angle to put on a knife. All the information has to be cobbled together from dozens of sources, some of which contradict one another. Can you suggest a definitive resource such as a book that we can trust to learn the basics?
        Thanks again for your reply. I am getting the valet in the mail today and looking forward to trying to get a mirror edge on it. I think I read you out a 12 degree angle on yours- what type of grind is it? This will replace my Spyderco Rookie as my EDC. What angle grind do you suggest?

      2. I put a 15 degree bevel on my valet iirc. Sorry, all my knowledge is gathered from forums (knifeforums RIP, bladeforum, wicked Edge forum) and facebook groups.

      3. Great info, thanks. What kind of grind did you put on it?
        I linked a page below that shows a bunch of different grinds, would you say that the 8 grinds listed here cover every grind that you would put on an EDC knife or are there a bunch of grinds not listed here that people use?


      4. That would be every grind I’d use, but I just sharpened it, it came with a flat grind and I gave it a flat bevel. A grind traditions over the entire blade while an edge is very minute in comparison.

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