CPM M4 vs K390

[anycal]

M4 cuts better. I only say that cause I don't have k390.
I care more about knife design than which steel it has.
Thought part of the knife enjoyment and experience was sharpening it? Wouldn't have to do that if it was a super magic steel that never dulls...

In a way I feel fortunate that I favorite a :spyder: model which lends it self to frequent sprints and exclusives. Being able to experience different steels in the same knife, with same ergonomics and blade geometries, allows one to better experience the differences and similarities of various steels.

I had the M4 PM2 for about a year and a half, and I feel like I know how it sharpens and how the edge behaves. And although I have the K390 PM2, it is still too new to adequately compare the two steels.

[blues]

Poor M4. Being treated like a jilted lover.

Well, I still like M4 and I'm not ashamed to say it in public!

(Even if I do like K390. But then, I never said I was monogamous.)

[Deadboxhero]

Poor M4. Being treated like a jilted lover.

Well, I still like M4 and I'm not ashamed to say it in public!

(Even if I do like K390. But then, I never said I was monogamous.)

From a steel nerd point of view I never get excited about the names or reputations of things, but how they work.

With the M4 it's not as capable as the other available steels on the market.

M4 was my first love, and one of the first steels I was trying to maximize performance with.
It has inherit limits due to its chemistry that other materials do not, so M4 was abandoned.

It's still a good steel, still makes a nice aggressive, sharp edge that people will love but there are just more capable steels in that range.

I personally will not make knives from M4 because for the same price I can buy other steels and get more performance juiced out of them.

[Deadboxhero]

One upon a time, M4 was my first super steel folder, Gayle Bradley 1, I bought it from Derrick in person at Knivesshipfree from his store front. I remember pestering him with questions about steel and such and going home and cross referencing with other folks experiences online, I was an experienced sharpener at the time but I never dove deep into the fancy super steels because I didn't understand the purpose since I knew how to sharpen. I was making good overtime money at the time on the 911 ambulance as an EMT so I had some extra cash to spend. I did a little research and I was intrigued that the M4 was harder and tougher and let's be real :D the name sounded cooler that the other fancy steels.

I'll always treasure those memories with Derrick, he was the first to also show me what CBN was, at the time I was Stropping with white and green bark river buffing compound on a leather paddle Strop.
Derrick pulls out a strop loaded with CBN "Shawn you gotta check this out"
I Stropped my newly purchased GB 1 in M4 and it was love at first pass, there was no going backwards ever after that.

The edge was unlike anything I had experienced up to that point. It's has sharper and still had good aggression but was just sticky, crazy sticky.

I bout the strop set from Derrick which was expensive, $135 if I'm remembering correctly for a dual sided paddle Strop with two 2 oz bottles of emulsion at 1um and 0.5um but I didn't understand since it was my first one that these kinds of things are expensive due to the raw materials.

I remember going home and Stropping every knife in the house and the endless joy of solving the riddles of this new super power I felt I had with this Strop.

I noticed that the M4 just always came up more intense than the vg10, S30v and simple carbon steels had at the time and that in use the GB1 held best so that I didn't have to use my pocket stone I carried, I could sharpen when I wanted to not because I had to, that really hit me and have loved the super steels ever since.

That's basically how the "super steel" Pm tool steel obsession started and the love for super abrasives many many years ago.

I've grown a great deal since than and have been on the creator side of things for the past few years now.

So I don't hate M4, Just evolved from it to other things and take what I've learned over the years to see the potential in other things as well.

[Chumango]

Shawn, you clearly like K390. How would you compare 10V to it? Edge strength, edge it takes, edge it holds, all else being equal in terms of good heat treat and geometry.

[Deadboxhero]

Shawn, you clearly like K390. How would you compare 10V to it? Edge strength, edge it takes, edge it holds, all else being equal in terms of good heat treat and geometry.

They are almost analogs, any differences I've noticed have been from different HT, processing, Geometry, edge finish and how they were sharpened or tested and used to evaluate.

In the knives I've made, The k390 may have been finer structured and the 10v and the 10v ever so slightly more aggressive but I haven't really dedicated the time to rule out the finer details, the micrographs Larrin took shows they are similar size and both have simliar undissolved vanadium carbide volumes and both have several paths to get different microstructures with HT and high HRC can be obtained 67-68 max on both.



There isn't anything on the market for people to compare these two steels directly right now since the farrid mehr was Discontinued.

I made a 9" Gyuto in 10v at 67rc, it takes a wonderfully aggressive edge.

[GarageBoy]

So k390, maxamet, and 15v all take more aggressive edges than m4, but are still "tough enough" for typical folder use?
I hope bladehq/dlt/whomever does a 15v or 10v exclusive set, then
On that note - can't wait for the 3B collab

[Deadboxhero]

So k390, maxamet, and 15v all take more aggressive edges than m4, but are still "tough enough" for typical folder use?
I hope bladehq/dlt/whomever does a 15v or 10v exclusive set, then
On that note - can't wait for the 3B collab

Definitely capable of EDC.

[abbazaba]

One upon a time...

Thank you for sharing. I had a similar experience with my first M4 and that why it became my benchmark... It was the first steel that I truly enjoyed.

[Deadboxhero]

One upon a time...

Thank you for sharing. I had a similar experience with my first M4 and that why it became my benchmark... It was the first steel that I truly enjoyed.

Yes, I'm often associated with down casting M4 but It's from place of experience over a period of time.

I loved M4 so much it started me down the path of geeking out hard on knife steels.

I was disappointed with the S30v puukko that was available at the time.

I got linked up with custom Knife maker Daniel Haramina in Croatia "Malanika" and would send him CPM M4 with Peter's HT with a custom protocol, Brad at Peters was very open to allowing me to be creative.

At the time, it was revolutionary since none of those knives had those kinds of steel nor did anyone know if it would be stable enough or work.

Well it worked great and the rest is history.

So I enjoyed helping get the first traditional puukkos in CPM M4 at 63rc.

Over a period of using and testing, I simply wanted more than M4 could offer so I moved on to other tool steels like 4v and cruwear that offered better stability at higher hardness than M4 could.

Dutch Bushcraft Knives really brought the concept to a wider audience with their videos when they reviewed Malanikas knives in 4v and other tool steels.

Now many makers in Europe make traditional puukkos using CPM 4v, Vanadis 4 Extra, Cruwear etc. I liked knowing I played a part in that.

I still feel Daniel is the best though.