Talking Steel: CPM-Magnacut
ฝัง
- เผยแพร่เมื่อ 7 ก.ค. 2021
- In a nutshell, Dr. Larrin Thomas designed a steel with the edge retention and toughness of CPM-4V while being more stainless than CPM-20CV. By carefully balancing the chemistry, Magnacut manages to form only extremely fine vanadium and niobium carbides that maximize the edge retention while minimizing the reduction in toughness.
It’s a stainless steel that has no real compromises and essentially can be used in any role where 4V edge retention is desired. The next step is to have the same achievement for a 10V or 15V class steel making a Sumacut and then a new age will truly have dawned in knife steel.
Link to Article: knifesteelnerds.com/2021/03/2...
![[ไฮไลต์] แบดมินตันหญิง "เมย์ รัชนก" ไทย vs เบลเยี่ยม รอบแบ่งกลุ่ม | โอลิมปิก 2024](http://i.ytimg.com/vi/qfMROCoiKMY/mqdefault.jpg)
![[ไฮไลต์] แบดมินตันชาย วิว กุลวุฒิ ไทย vs ฟินแลนด์ รอบแบ่งกลุ่ม | โอลิมปิก 2024](http://i.ytimg.com/vi/GIbeFO0tvnQ/mqdefault.jpg)
Welcome to the Magnacut video club hehe! Thanks for writing out the technical details, I appreciate your precision and this was helpful to me!
Figured I’d add my 2cents to the mix! Glad you enjoyed it
@@EngineersPerspective701 haha, your 2 cents is some people's 20 bucks. Keep up the good work.
I read Larrin Thomas' story of developing Magnacut and he was very pleased with the final results. It is easier to sharpen, but it still holds an edge superior to most steels and it cut more rope to the middle of the field with most "super steels". Cedric cut over 500 cuts and his saltwater test didn't faze the Magnacut. I recommend to everyone interested to read the linked article above.
Funny enough there is an old old steel that's tougher than any new steel and that's S5, I asked Larrin in an email about S5 as I used it for hard HRC 59-60 axes and he sent me a chart showing it passing everything in toughness. S7 is tough as well, but it doesn't reach the hardness levels of S5 nor is it as tough.
I was very surprised by Pete's results especially with the Mako being at a target of 62HRc I believe. Definitely great for getting the word out there on it.
S5 is raw toughness for sure! But not sure it would present itself quite as well in high performance knife blades where strength and crispy edges are a focus. Looks miles ahead of 1095 for sure!
Seen it used in knife applications much?
@@EngineersPerspective701 I could only get drop offs 3/8ths thick from my job in a machine shop. I was made the heat treater when I mentioned to the boss's wife that I could make him a custom knife (He hunted big game) as it was/is my hobby. So I had HT added to my job description, but one day we acquired some Blanchard ground 4mm thick S5. I made 4 stub tang knives out of it and since "Special Jobs" TIG welder was another job I did, I brazed some stainless onto the stubs.
Note, I have 2 Masters degrees, one in engineering and one in biology with BS in Organic Chemistry and I worked my way through college welding, sheet metal and running fishing Charters on my dad's boat. At one point Rockwell paid for my advanced degrees so, cool. I was hired as an engineer/chemist, but their welders couldn't weld complicated aluminum parts and I could.
The knives were as good as anything in their class at HRC 61-62 hard with a 74 hour Liquid nitrogen soak over the weekend. Didn't even rust easily, better than O1V my fav for carbon alloys. When I say O1V I mean the O1 that has the 0.2% vanadium for restricting grain growth so one can soak it at 1475 for longer than the spec sheet says. A 15 to 20 minute soak improves the edge holding and toughness all things being equal.
The S5 blades were outstanding for toughness, but didn't hold an edge any better than O1 or 1095 at the same hardness, but if you leave 1095 or O1 at 62 hard they will be much more brittle than S5 obviously. Now Larrin sent me a chart showing that S5's toughness falls rapidly above 60 on the C scale. So at 61 it isn't past 4V toughness like 59 hardness is.
@@MountainFisher Damn you'd be an interesting guy to hangout with! I've built several medium scale lab setups so I can MIG and TIG poorly but good enough for structural and low pressure.
Sounds like it performed well and was easy enough to work with. As I see it the true battle of low alloy steels is keeping that gain growth in control when shooting for higher hardness. Those grain refining adds like in O1V and S5 make it night and day to work with I'm sure! They still loose that toughness advantage quick like you're saying with 4V being comparable at 61HRc even.
That makes me even more impressed with what has been accomplished with steel like 4V and Magnacut!
@@EngineersPerspective701 Here is S5 chemical analysis, the top line is typical American analysis and lower is minimum from a seller of metals from China, what I refer to as Chinesium. I swear, what the Hell is up with their QC over there? Well anyway I have one S5 knife left and one case hardened Ax-head looking for a handle.
C CO CR MN MO NI P S SI V
.65 .50 1.0 1.35 2.25 .35
.55 .35 .70 .50 1.75 .25
As you can see S5 has high manganese like O1 does and a good chunk of Moly. Certainly more Vanadium than O1 as well. The knives I made worked very well and would bend before they broke. My axes are really super axes when you look at what so many axes are made from. Low carbon 1055 or 4140 as if L6 wouldn't make a better axe for $2 more in materials. Pathetic really, but Husqvarna's axe is at HRC 59 and doesn't cost an arm and a leg.
edit; I said "case hardened" axe because when forging I used pulverized pure activated Carbon mixed in my Borax flux to try and keep decarb down, but with forging any lower carbon steel I was quick with my forging having access to a Little Giant 50 lb trip hammer.
S7 is a well known awesome steel to use in the sword world, where hardness isn't nearly as important but toughness is extremely important.
I would be really excited to see a video of you talking with Larren. Like big brown bear does but asking questions from an engineers perspective. Big brown bear asks questions from a knife makers perspective but I would like to hear you guys drill in to more of the science. Good video man!
I really appreciate the comment! I don't think my knowledge is quite there yet to add value to what Larrin has to say but my knowledge is growing a lot faster thanks to this channel!
BBB has so much practical experience from testing, using, sharpening, heat treating, grinding those steels I don't think I'll ever be able to match that! My 5-yr goal is to get a small shop with some equipment and make knives as a hobby so maybe then I will at least approach him.
Cant wait to try out the magnacut in whatever form factor, and sign me up for some of that summa cut too!
Same! I am incredibly stoked that major manufacturers seem to be taking note of this. If/when CRK switches to Magnacut at 62HRc I'm finally buying one!
@@EngineersPerspective701 I've held off from ever buying one as well, but this might push me forward on the decision also. Magnacut in that hollow ground blade they do might be nice.
I remember commenting your videos long time ago :) cool to see you again
Good to see you back!
@@EngineersPerspective701 But did you delete old videos ?
@@dimmacommunication I actually took down one I had on Cruwear and M4 because I made a mistake talking about M4. It’s has all moly and tungsten carbides in it (note M6C not pure MC type of tungsten carbide) and I said it had chromium carbide.
Interesting new CPM product. Some big brands could really step up their game. Love my Kershaw Tilt in Vanex. Not so much with the Spyderco Maxemet, chippy and fussy to perfect an edge. ✌
It looks like production makers are ready to push this one to a level that I've been begging for! CRK is looking at 62HRc target and I've seen some other stuff in the same range. That will be a major upgrade from many current offerings with a sweet toughness, hardness, edge retention, sharpenability balance.
Personally really enjoy Maxamet. It took me a long time to decide but I spent a few dedicated weeks with it and now it's one of my top choices. Does take some learning and effort to get that quality edge and it can microchip with lateral forces.
I would love to see damascus steel made out of MagnaCut and 4V
Interesting, what has you drawn to that combo?
What is k390s toughness? Will it hold the same edge angle as magnacut? Being a year later now, they have corrected the heat treatment up 63-64 at the urgings of Larrin which really unlocks magnacuts potential by all accounts. I don't quite understand the toughness aspect, I've always assumed that the tougher steels would hold a finer edge. But rex45 at at 66 to 66 is down around 5 lbs in Larrins testing. Yet I watched a guy here on you tube cutting and torqing on a brass rod with rex45 and m4. He rolled the edge on the m4 and had very little damage on the rex45.
K390 toughness is very good relative to mid to high carbide stainless steels. Magnacut will likely hold lower angles better at the same hardness.
There is a difference between toughness and strength. Generally a harder heat treatment will resist deformation better than a softer one. When it does deform it’s catastrophic which is the down side. I love Rex45 because it’s heat treated to have fantastic strength so it never rolls on me.
On the flip side the primary dulling mechanism for S30V in my usage is edge rolling.
I think this steel would make a near perfect survival knife. It’s tough so it will handle abuse, it’s stainless so it’s maintenance free, and it still has more edge retention than common carbon steel.
Coincidentally the higher toughness allows for a very acute cutting angle, because it’s less prone to rolling and chipping. In real life this is one kind of wear resistance, because the edge stays usable longer.
If you're already looking for stainless it's pretty much the top of the heap except that other options with less VC will certainly be easier to sharpen with very rudimentary tools like river rocks if that's your game plan.
I think it can still be sharpened on a rock in a pinch, it just takes longer. Ideally people should always carry a portable sharpener with them when going outdoors. Some knives actually have sharpeners attached or built into the sheath.
For people who value toughness, rust resistance, and ease of sharpening, there’s already Sandvik 14C28N. Tougher than Magnacut, very rust resistant, but with wear resistance comparable to the humble AUS8/8CR13MoV.
Nice right up, but remember edge retention equals hard to sharpen, k390 might not need sharpening often but when it does I doubt you could field sharpen it.
I think the term “hard to sharpen” is generally not well used.
Is K390 at 65HRc “hard” as in difficult to sharpen? For me the answer is no it is not. Does it take longer with the same grit rating and essentially require diamond abrasives? Yes it certainly does.
So I think suggesting that the difficulty to getting a quality edge on it is high isn’t necessarily true especially with the availability and low cost of diamond abrasives today.
As for field sharpening do you mean using a work sharp field sharpener or DMT diafold? Because those are cake for sharpening K390. A river rock found in the wilderness though is not going to “cut” it (pun intended)!
Can't wait til more of the mainstream manufacturers like Spyderco and Benchmade start producing more volume of knives with magnacut
Super excited for the magancut native 5s! Enjoying the mule as well after about 10 edges it’s really something good
Hey,
So in my quest for understanding, when it comes to knives used for combat extreme survival conditions, how do you feel about 80CrV2 as in Winklers offerings? Would the MagnaCut be better than that? I know steels like 1095!(KaBar) have been used for years etc.
Any other thoughts on what would be the best material for this type of knife?
I’m new to this world, Thanks much! 👍🏼
Appreciate the question!
Just to be clear, I am no survival or combat expert! If you’re looking for stainless then yes this is probably the highest end option out there. You could probably get something in AEB-L or Nitro-V for less that would also be good choices.
If you’re not looking for stainless but also high edge retention choose 3V. For a more basic carbon steel 80CrV2 is a great option and far superior to 1095 because it has grain refining elements in it that “pin” the grains from becoming too large in heat treatment. This lends to a notably tougher blade at the same hardness when compared to the 10XX series of steel.
@@EngineersPerspective701 Ok Gotcha! So would you say that the 3V or 80CrV2 are going to be still much tougher than the MagnaCut? Or is the MagnaCut now truly competing with these carbon materials?
From what you said in the video, it seems like the MagnaCut is really creating the best of all worlds and I guess the question is, is that a high enough across the board ability in terms of extreme use or does an extreme use knife material need to wait for the next “SummaCut” category? Ha!
@@MylesDavid it really comes down to the end geometry and heat treat but it’s safe to generally say yes Magnacut is right there with all these!
Magnacut in an Esee or Falknaven form factor? He’ll yeah, you couldn’t break it regardless of HRc and it would blow away the steels offered by them currently.
Love you’re technical approach in this video. I’ve struggled to sharpen Magnacut on my Chosera 400- 3000 professional stones. Would venev diamond stones be a better option?
For sure they are. I normally use my Venevs on my Meglio Magnacut Gyuto and love that edge
@@EngineersPerspective701 thanks so much for your thoughts. I was surprised at the difficulty of sharpening my Acta Non Verba A100 knife on chosera stones. The Vanadium Carbide content is not that high but the HRC is 64 so maybe the combo of steel and HRC is the culprit.
I feel like he may design a super high wear resistant 10v style stainless, he got magnacut out and helped out to make apex ultra to compete with forging steels like the 10xx series, 52100 and such so it would make sense. Make a balanced steel, a better forging ingot steel, then a super high wear resistant steel
I know he’s also working on a high niobium steel too so maybe after the apex ultra and that it’ll be a focus! Agree that it’s a natural progression and I’m very optimistic that my “Sumacut” will be coming out in the next few years
How difficult is it to sharpen for beginners?
And how does it compared to M390/20CV/ELMAX in terms sharpening difficulty?
This depends on the specific issues you have with M390, etc. but for most people Magnacut will yield better results faster and with less skill. No guarantee though!
If you can sharpen standard production M390/20cv, you shouldn't have any issues with Magnacut. My Magnacut Mule was as easy to sharpen as those steels. The differences were too small for me to notice anything significant.
Knife mfg's need to run magnacut at 65Hrc to maximize its potential just like k398 otherwise customers are being short changed
I think that would be extremely difficult for a factory production line to pull off. Even custom makers that’s pushing it way up there for Magnacut
@@EngineersPerspective701 well at least strive for that.
Spyderco runs batches of particular steels to 64hrc.
I think irs money well spent if a knife can keep its cutting edge 10X longer without chipping, the steel capable of doing so should be offered as such where the knowing consumer is allowed to purchase such a steel.
Pete from Cedric & Ada channel on YT just pronounced the new king in knife steels 15V from Spyderco and I believe it cut over 2000 cuts in that sisal rope he uses, absolutely incredible! (Approaching pure tungsten carbide sharpness)
No you cannot sharpen with ceramics or stone its diamonds only however the tool that is derived from 64hrc 15v sharpened by diamonds to a low angle is unparalleled excellence!
Consumers should be made aware of a particular steels attributes before purchasing, with that being said, knife makers need to offer the best heat treatment available because its shortchanging the unwary consumer.
While I love my Kershaw Link in 20CV I know the steel is nowhere near its potential and is half baked because it takes a lot to finish a knife that uses hard steel 62hrc+
So I got a 20cv blade that performs as well as properly hardened D2 maximised to 62HRC.
What im saying is if a knife maker is going to promote and charge for exotic steel it needs to properly harden that steel to maximize that steels potential or they are stealing hard earned money from the consumer ☺️
Thanks for the reply.
Aloha
Why did he give it THAT name?
What’s wrong with it? The Latin makes sense and the industry history is near too! He wrote an article about the whole development process so you can read about the naming there
It's a nod to some of the early steel developers and their steels that he admired I think. They had a handful of steels with names ending in "cut".