M390 Steel – History and Properties (and 20CV and 204P)

[Larrin]

New article about M390 steel, which has a surprisingly convoluted history in knives. The steel was released prior to many other powder metallurgy stainless steels, but was never used in knives to any great extent until a couple decades later. I also summarized its properties including microstructure, edge retention, toughness, corrosion resistance, etc. https://knifesteelnerds.com/2020/06/01/ ... -and-204p/

[jdw]

You have a tremendous gift of taking complex knowledge and making it accessible to a layperson like myself. Many thanks for your hard work and sharing your expertise.

[Larrin]

You have a tremendous gift of taking complex knowledge and making it accessible to a layperson like myself. Many thanks for your hard work and sharing your expertise.

Thank you!

[dj moonbat]

Looking at all those rankings in different categories, I realize I need to learn more about Vanax. Have you written on it, Larrin?

I was also reassured to see that I was right in my skepticism of claims that M390 was relatively tough. I am slowly getting better at figuring out what a steel’s chemistry is likely to do. The added variable of heat treat protocol still baffles me, though.

[Larrin]

Looking at all those rankings in different categories, I realize I need to learn more about Vanax. Have you written on it, Larrin?

I was also reassured to see that I was right in my skepticism of claims that M390 was relatively tough. I am slowly getting better at figuring out what a steel’s chemistry is likely to do. The added variable of heat treat protocol still baffles me, though.

I don’t have an article just like this one on Vanax, but I have written about it before:
https://knifesteelnerds.com/2018/09/17/ ... fe-steels/
https://knifesteelnerds.com/2019/03/25/ ... ing-vanax/

[blues]

Good stuff, Larrin, as always. Thanks for the education.

[BigHonu]

Thank you very much for the article. Subscribed!

[AlexRus]

Thank you Larrin! Awesome article!

[Larrin]

Thank you very much for the article. Subscribed!

Awesome!

[zuludelta]

I learned a lot from reading this latest article, thanks Larrin. M390/20CV is one of those steels that is off my radar, so to speak (primarily because it's mostly found in knives that are at a price point above what I'm accustomed to paying for a work folder), so it was nice to get a detailed look at its properties.

[Larrin]

I learned a lot from reading this latest article, thanks Larrin. M390/20CV is one of those steels that is off my radar, so to speak (primarily because it's mostly found in knives that are at a price point above what I'm accustomed to paying for a work folder), so it was nice to get a detailed look at its properties.

It’s taken me a while to really get a handle on this steel so it was nice to get it all written down.

[Cycletroll]

Thanks Larrin!
This latest article supports something I've always suspected; that m390 and its analogs are not as tough as claimed.

[fixall]

Corrosion resistance is inconsequential to me most of the time, so it's seeming like ease of sharpening is about the only advantage M390/20CV/204P gives me over S30V. All this testing is really making me appreciate S30V more as a good all around knife steel at a reasonable price... And I think I'm also starting to understand why Spyderco switched from S35VN to S30V.

Good stuff as always Larrin!

[zuludelta]

All this testing is really making me appreciate S30V more as a good all around knife steel at a reasonable price...

I agree... Larrin's articles have made me appreciate S30V that much more. It really is a great all-around knife steel for its price. You can get a tougher steel, or a more corrosion-resistant steel, or one with more wear-resistance, but there will be a trade-off either in cost or one of the other physical properties and at least for my purposes, that trade-off usually isn't worth it. I mean, if I need a steel that is significantly more corrosion-resistant than S30V (or VG-10 for that matter), that's probably because I'm going to be in or around saltwater for an extended time, and if that's the case, I'm taking a purpose-designed water knife in H1 or LC200N.

Additionally, this article also made me appreciate Spyderco's decision to go with S110V as the long-wearing stainless steel for the company's Golden models.

And I think I'm also starting to understand why Spyderco switched from S35VN to S30V.

I will admit, when Spyderco announced a few years ago that they were switching the Native 5 and Native 5 Lightweight from S35VN to S30V for performance reasons (right at the time when many other companies were switching to S35VN as their entry-level "prestige steel"), I was a little skeptical—I thought it was probably motivated more by a desire to limit production costs.

But now that I have a better understanding of the properties I find useful in a folding knife and after seeing all this independent testing by Larrin, I get why Spyderco did what it did. The extra toughness & incremental improvement in stainlessness of S35VN doesn't really outweigh S30V's edge-holding and price advantage as far as what I use folding knives for (I still love my S35VN Native 5 Lightweight though).

[JD Spydo]

Thanks again for another chunk of great knowledge you are kind enough to share with us Larrin :) I got my first M390 folder about 4 years ago when I traded one of my Captain models for a slightly used M390 Military model. It now ranks as one of my very best trades of all time. Oh I know that M390 isn't the best blade steel on the planet but I sure like it. But that C-36 Military with M390 blade steel is one great plain edged folder :cool:

I've had many C-36 Military models in about 10 different blade steels over the years but until I got that M390 Military folder I had never had a plain edged blade steel that takes the punishment that I give my EDC folder during the typical week like my M390 Military can endure. If there is a supersteel that can outperform M390 by a wide margin that will be the next Military model I'll purchase.

I hope some day Larrin we can do some tests on different blade steels and how they perform in SE. Thanks again buddy for sharing all this great information with us

[Tucson Tom]

Very nice article. Thanks for taking the time to research it all and write it up.
There is no question that there is a lot more work invested than meets the eye.
Thanks.

[Larrin]

Very nice article. Thanks for taking the time to research it all and write it up.
There is no question that there is a lot more work invested than meets the eye.
Thanks.

I wasted two days tracking down sources on a defunct steel called MV11K that didn't even make it into the article!