CPM MagnaCut | Hacker News Reader

CPM MagnaCut

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375 pointstopsycatt108 comments

Since I presume steel is a more or less uniform substance compared to biological processes, why is metallurgical research still more or less experiment first?

Shouldn't it possible nowadays to bruteforce a search for an alloy of any given properties using computer simulations of the atomic or molecular structures?

No. This is knives, not science.

Per TFA, it is to an extent? The author briefly discusses a computational search of the design space, and uses that data to encourage the partner company to make a batch of the steel.

That said, simulating material properties from atomic scale principles seems nontrivial compared to predicting them given observed parameters and properties of other alloys. I’d be interested in more informed comments on that possibility!

The search space is much, much more vast than you'd imagine, and there are so many ways that things get non-linear that we have absolutely no idea how (way) more than 99.9999% of the possible alloys that we could make would actually perform in reality. The way most of the alloys we are using were found was that we started with something that we already knew, and then tweaked from there to optimize some property.

It's a good question; unusually, that doesn't mean I don't have a good answer.

Steel is so far from being a more or less uniform substance that it's not even funny. There are four major phases that play roles even in the commonest carbon steel (ferrite, cementite, austenite, and martensite), plus others that can form at times like graphite, which plays an important role in cast irons. Ferrite and cementite can form nanolaminated microstructures called pearlite and bainite which have a major influence on the properties of the steel, and there are other microstructures that form depending on cooling speed, heat treatment, and cold working. So even the simplest steel is a nanostructured composite of metal and ceramic whose properties are hard to model computationally, though great strides have been made in recent decades.

Then, once you add other alloying elements besides those two (intentionally or not), steel stops being so simple. You can find phase diagrams for most of the binary systems (vanadium-carbon, for example, or vanadium-iron) but most of the ternary systems probably include compounds that haven't been identified yet. In theory you could find them computationally, I think. Even when you have a phase diagram, though, that doesn't tell you how fast the phase transitions happen, which depends on things like the crystal structures of intermediate unstable phases.

I don't know anything about this stuff, I just read about it. Recommended! Start with https://www.tf.uni-kiel.de/matwis/amat/generalinfo_en/guided...

Naive question: Has anyone tried to whack these questions with the machine learning hammer? I figure if we can do protein folding [0], we should be able to do knives.

[0] https://deepmind.com/blog/article/alphafold-a-solution-to-a-...

Folks are certainly working on it from many dimensions, but it’s a pretty hard problem since getting ground truth data involves making and testing materials, which is a very different problem to automate than training machine learning models. You need a fairly cross disciplinary team to make progress. As an example of folks doing good work: https://a3md.utoronto.ca/

I don’t believe we have a good way to compute various macro properties of something like steel. We can compute density and what not, but how much it holds its sharpness or something is something I haven’t seen.

So I am not sure how to get the training data needed for ML.

(Computational chemist, but not computational materials scientist. So could be wrong!)

Kind of, deepmind actually recently published results in metal oxides:

https://ai.googleblog.com/2021/10/finding-complex-metal-oxid...

Steel has similar complexity since the number of combinations is so vast.

That's still only, what, twenty or thirty dimensions? I guess it's hard enough to gather data that it's not as simple as feeding it a big black-box optimizer, something like SageMaker or Vizier that's designed to tune ML models with week-long training times and dozens of hyperparameters, but that'd still be quite a bit more powerful than the manual search that the author talks about.

Questions about prime numbers are asked in one dimension.

The manual search is guided by a lot of very rigorous theory-of-experiment. It's not just trial and error, it's quite a bit more.

And do what? ML requires a way to know if it’s making correct predictions.

This is actually a great question and doesn't deserve to be downvoted. Indeed this is one of the considerations that led me to leave materials science research field after a couple of undergraduate projects with PhD candidates.

It turns out that the domain between Angstroms (where we can computationally model atomic interactions accounting for quantum effects) and Milli (where standard Newton's laws and therefore mechanical engineering tools can be used) is a vast computational desert.

Most properties that affect bulk material properties happen to be developed in the micro-domain (note the photographs in the article) and almost 20 years after I've left the field, I don't believe there's still any rigorous "first-principles" based computational approach yet. In other words, materials are not uniform in the micro domain and this is where materials properties develop.

So materials research process becomes hypothize, create material batch, test it 20 ways, rinse and repeat for a slightly different composition or process

Even the software mentioned in the article (thermo-calc) is primarily empirical with some very smart extrapolations and modeling added (note the first step is experimental data capture [1]. It definitely is a massive step forward from when I was in the field but definitely not first principles based modeling.

[1] https://thermocalc.com/about-us/methodology/the-calphad-meth...

appreciate your use of "first principles based modeling". in my program, that's what we meant by "model based", but usage in the AI community is quite different

your verbiage concisely captures what's so important about the concept

AFAICT that is, to a large degree, what the author did. Much of the initial "exploration" seems to have been done in Thermo-Calc, with physical experiments following. IMO the novelty in process is more exciting than the novelty of the result.

There's a startup out of U of Toronto working on exactly this:

https://www.thephaseshift.com/

Former computational materials scientist here. There are groups that are using ML for finding materials to simulate, and some beginning to use it to speed up simulations. Still that said, simulating cutting, abrasion, sharpening (I suppose it would be called to some extent tribology) is still in the infancy of simulation. Steel is extra difficult compared to other materials, and it has such a history of innovation that all exists at a sort of mesoscale out of reach of contemporary atomistic simulations. Still some have attempted it: https://www.dierk-raabe.com/icme/ or more recently: https://www.sciencedirect.com/science/article/abs/pii/S09270... Still the from Simulation/Search -> Experiment pipeline is working generally at much smaller scales that steel structures for now. ie micro instead of nano

The important qualities of steel emerge out of microstructure: nanometer to millimeter sized features (several different crystal structures in the same material interacting through the boundaries between them and the bulk properties in them) which requires quantum interactions to be tracked through many orders of magnitude of scale. This includes how these different structures are formed though many stages of melting, tempering, work hardening, etc. In other words it is hideously computationally complex.

One of many fields where yes there is a lot of simulation and yes it is developing but still quite far from having anything close to a complete model which can escape the need for extensive experimentation.

There is a sort of prevalent idea among people outside these fields that simulations exist which can just handle anything. This is very wrong and quite far away.

In metallurgy, several computational models are available based on specific applications. University of Cambridge is involved in neural network modeling. Just recently I published a paper that analyzed a welding electrode database to provide specific insights. One could see it here, https://s3.amazonaws.com/WJ-www.aws.org/supplement/2021.100....

Really interesting read. It's cool that a company like Crucible was willing to consider a proposal for something as expensive, time consuming, and potentially fruitless as a new steel from essentially someone off the street.

Larrin's father is a famous custom knife maker who worked with making his own Damascus-style steel. Larrin, though his father, is well-known among the knife community.

It is unfair to Larrin to attribute his success and well-knowness to the father.

I wasn't trying to do that so I should clarify. MagnaCut is, so far, a success because of his unique approach. I asked on another forum if MagnaCut is using some new process that makes the balance of properties so much better than other steels on the market. Most cutlery steel dates back decades. I thought maybe what MagnaCut is doing relies on technology that wasn't available back then. Larrin said no. He deserves credit for his fresh approach to making a cutlery steel, and I should not have implied otherwise.

My poorly worded response was more to Crucible taking a chance on somebody off the street. Larrin is not some unknown quantity. He has connections in the knife industry, including Crucible. He's also a metallurgist with accomplishments in his own right. Crucible still took a risk, but it wasn't a huge one.

Not really sure I’d call Larrin “someone off the street.” They guy literally wrote the book on modern knife metallurgy and has a PhD in the science. https://www.amazon.com/Knife-Engineering-Steel-Treating-Geom...

He also has a well known website and is considered one of the worlds leading experts on knife steels and knife craft.

He has a PhD Metallurgical Engineering and works in the steel industry (though on automotive steels, not on knife steels). Not quite the same as someone off the street. From TFA the company was mainly worried that his knife-steel knowledge was purely academic (since he's never worked professionally on high carbon knife steels).

Very cool to see this pop up on Hacker News. I'm into pocket knives, and Larrin's new steel is generating a lot of hype among knife users and makers.

This is a huge article. Can anyone give a 1-paragraph synopsis of its main thrust?

MagnaCut is the first knife steel that does the best job of balancing edge retention, toughness, and corrosion resistance. It is basically a stainless 4V (if that means anything to you). Larrin focused on reducing the amount or chromium needed. Lots of steels will dump chromium into the steel to help corrosion resistance. This only helps if chromium remains in solution and not forming carbides with the iron. Chromium carbides don't offer much in the way of wear resistance (unless you have a ton of them like in ZDP-189) and they are large carbides (relatively speaking) even after the particle metallurgy process. Basically, you give up toughness when helping corrosion resistance (ignoring steels with nitrogen). Larrin uses a lower amount of chromium than you would expect, but it remains in solution. So you get the stain resistance you want without the chromium carbides.

Other benefits of the steel include grindability, which means makers can spend less time and abrasives on shaping the knife. You can obtain higher hardness than a standard stainless steel, which helps with forming an apex and removing the burr (sharpness for lack of a better word).

Spyderco, a major player in the knife world, has a line of knives called their Salt series. These knives are supposed to be as rust-free as one can make. MagnaCut will first enter their catalog as a Salt knife. This was a big shock given how well LC200N (nitrogen-based steel used by NASA for ball bearings) can resist rust and remain tough (wear resistance isn't anything special though).

Bottom line, Larrin built a well-balanced steel exclusively for knives. Many steels are adopted from other industries or were "knife-specific" but based on something like 440C, which was never intended for cutlery. So MagnaCut is upending the knife steel market by offering something you can't get elsewhere.

Is it possible to sharpen such a thing when it does get dull, or does that require a professional?

In between sharpenings, does a steel work?

(Sorry, I don't know much about steel or knife making. I just appreciate a really good kitchen knife.)

When we think of knife performance, it is the geometry of the blade that is the most important. I can give you a knife in MagnaCut with a thick edge. It won't cut for crap. So you want a nice, thin edge. Thin edges tend to roll/chip more easily. That is why you want a harder steel.

So if MagnaCut is run hard, it will most likely dull before rolling or chipping. It will still cut, especially if you have think geometry. Once a blade starts to roll/chip, performance really suffers. That's when you need to sharpen.

I have never sharpened MagnaCut, but it only has 4% vanadium (the hardest carbide) and 2% niobium (another hard carbide). You can probably get away with something like the Shapton Pro line of stones. They are readily available.

Hmm, is vanadium carbide really harder than tungsten carbide, even at room temperature?

All the research I have seen says vanadium is harder. That said, Sandrin Knives makes cutlery with a blade of nothing but tungsten carbide. This will outperform any steel easily. I have not seen a blade of nothing but vanadium. No idea if that is even possible.

https://usa.sandrinknives.com/

Interesting, thanks!

bob, what's your favorite resource(s) on learning to sharpen – both technique and theory (geometry, etc.)? I tried to get into the Cliff Stamp stuff, but it was really hard because everything was spread out across a zillion forum posts and YouTube videos.

Yeah I’ve bought a variety of tools over the years and all of them kind of suck. You need to be some sort of master craftsman with infinite time to use many of the sharpening techniques and tools or have already almost perfectly sharp knives.

You should Google your location + knife sharpening. There's probably a master craftsman within a few minutes drive of you that will sharpen your blades for a very reasonable price. There's a guy near me that will do small pocket knives for $2.50, prices go up from there. All of the local landscaping companies use him for their mower blades and chainsaws.

There is a fantastic place in Seattle that does it at 2$ an inch or something. Just takes about a month

I'm not bob, but I bought a ruixin pro 8 (~40AUD) and 3 diamond stones (~5AUD a piece) on aliexpress a couple of weeks ago.

Watched a YouTube video and got half a dozen kitchen knives sharp enough to shave arm hair in about an hour. They seem to be holding their edges reasonably well a couple of weeks later.

I'd previously not had much success with Japanese water stones and with the lansky(?) gadget.

It seems like the key part of the process is (a) detecting when you have formed a burr so you know when to change sides/move to the next grit and (b) stropping at the end (get the leather strip with polishing wax).

The Chinese gadget is a bit crude but was honestly surprisingly effective.

I don't think the theory is that complicated but getting good practical results reliably can be a bit tricky. The gadget seems to work quite well for that.

Ps: Just looked at Cliff Stamp's sharpening site. I think that's an order of magnitude sharper than I was going for with my kitchen knives.

Sorry, I stepped out to see the new Matrix film. I like the method of Murray Carter. He put out a DVD on blade sharpening, but has since released the entire thing on YouTube[1]. I have modified it a bit over time. I free-hand sharpen, but am not that great. You really only need a three-stone setup (coarse, medium, and fine) and a leather strop with diamond spray/paste. While diamonds or CBN are only really required for certain steels, I find diamonds to work wonders on a strop. You can get some quality stropping compound for cheap. I wouldn't worry about buying all of that at once though.

There are so many different methods and tools you can use. I say find a well regarded technique and stick with it. Sharpening takes time. Sharpening can be distilled down to forming an apex and removing the burr. It doesn't matter if you use soaking stones, a fixed-angle sharpener, splash and go stones, sharpen with both hands, etc. You need to build muscle memory so there is as little change in angle as you sharpen. That will develop the apex. Then you need to remove the burr. You'll use different strokes, different pressure, and different tools. Focus more on the technique and worry less about the tools. Maybe Murray Carter doesn't appeal to you. Take a look at Big Brown Bear and Michael Christy (also on YouTube). Find a method that makes sense to you and practice a lot. Start with a simple technique with fewer grit jumps. You can add complexity over time.

The best thing I got was a jeweler's loupe. You need to understand what you are doing (or not doing) at the apex to improve. Take your time and evaluate your work often. Even an inexpensive USB microscope is helpful.

[1] https://www.youtube.com/watch?v=Yk3IcKUtp8U

Knife nerd comes up with an idea for how to make a steel with a novel combination of hardness / toughness, edge retention, and corrosion resistance. Persuades a real steel company to make a batch, which is tested eighteen ways from Friday by him, the company, and a bunch of knifemakers. Result turns out to be as good as predicted, maybe even a bit better.

Bonus making it even more relevant to HN: most of the "discovery" was done via software, before any physical experiments (which are hard and expensive in this case). The fact that this new approach yielded good results is promising wrt developing steels with different properties.

new steel good

The custom knife industry was really excited about SM100 at first, as well.

What happened to SM100?

Impossible to work with; the start up making it stopped making it. I’ve seen amazing knives made from it, but the knife makers I know that did said “never more”

Larrin was on one of my favorite podcasts, Cooking Issues, to talk about various knife related things. Very good discussion.

Episode link: https://www.patreon.com/posts/knives-out-with-52817284

You do not need to be a Patron subscriber to listen to the episode. Also, if you're interested in the technical side of cooking and drink making, Cooking Issues is the podcast to listen to. There's a huge back catalog of shows on their former network, HRN, as well as a bunch of shows via their new arrangement.

Thanks. I occasionally read their blog back in the day, but didn't know they were still producing stuff.

And making stuff!: https://www.indiegogo.com/projects/searzall-pro#/

Now, that is a labor of love!

I find good chef's knives to be worth their price, but the truly awesome ones are a bit out of my price/performance range.

If I made my living as a chef, I might think differently.

I like to cook; I bought a carbon-steel chef's knife 25 years ago, made by Richardson Steel of Sheffield. Regrettably they don't make steel in Sheffield any more, and that brand was sold to some Chinese company. The knife rusts if you let it; I call the result a 'patina'. It takes a wicked edge. It's still my go-to kitchen knife.

Just now I'm a beardie-wierdie; but I usually shave through the summer, using straight razors. These are also carbon steel, although I think one of my razors at least must have some chromium in it - it seems to resist tarnishing.

So: I wonder how this material compares to that Sheffield carbon steel for hardness and toughness. And I wonder how it compares with the Solingen steel my two daily razors are made of. As far as I'm concerned, a straight razor is the pinnacle of blade-making (I might take a different view if I was into swords).

One of my razors belonged to my father, and is Sheffield carbon steel. It was made in the 1930s, and I can't get it nearly as sharp as the modern Solingen steel razors (I tried shaving with it once, but it wasn't 'smooth').

I didn't get what hardening, tempering and annealing processes he applied; that makes a huge difference to the kind of steel you end up with.

I'm just a blade user, not a metallurgist or cutler. I'm just interested in high-performance blades. I wonder if this metal makes nice razors?

How does this compare to Japanese steels such as HAP40 and Aogami White/Blue/Super?

If you look at White/Blue/Super funny they will rust. HAP40 is a high-speed tool steel. CPM M4 is a good comparison to it. MagnaCut will offer corrosion resistance that you don't tend to see in Japanese steels. MagnaCut will have better edge retention than White/Blue/Super. Those steels are low-alloy and rely on high hardness for wear resistance. MagnaCut has vanadium and niobium plus it can get pretty hard as well. MagnaCut is so far ahead of White/Blue/Super in this regard. Japanese steels are known for being great to sharpen (even HAP40). From what I have read, MagnaCut sharpens well.

If we say that MagnaCut = stainless 4V and HAP40 = CPM M4, then HAP40 should have some more edge retention but less toughness when compared to MagnaCut. The differences aren't all that great. Corrosion resistance is the real difference maker.

Do you know how tungsten carbide with nickel binder stacks up in comparison? The usual cobalt binder of course isn't that good in terms of corrosion resistance, but for e.g. vegetable knife purposes, sharpness is very much required, toughness only so much as a brittle blade shatters if you look at it funny, and edge retention determines whether you have to (learn to) sharpen it at location, or can transport it to a service center.

It is hard to make comparisons like this. I know that is a crappy answer. But geometry by far the most important characteristic. How thick is the overall blade stock? How thick is the knife behind the edge? Those two things will matter more than steel composition. Then you have heat treat. A great steel with a crappy heat treat is going to make for a lackluster knife.

But, regarding tungsten. There is a steel called Maxamet, and it is used in several knives by Spyderco. It should be noted that I am a Spyderco fanboy, so take my recommendation of this company with a grain of salt. I like them more than any other production knife company, perhaps to a fault. Anyways, Maxamet is run really hard, like 67 HRC. Most production companies will run their knives in the upper 50's so the knives roll instead of chip. Quality production companies (Spyderco, Benchmade, Hinderer, Chris Reeve, etc.) will run most of their steels to around 59-60 HRC. Maxamet can cut for a long, long time. This steel has 2.15% iron (which helps with attaining a higher hardness), 10% cobalt, 13% tungsten, and 6% vanadium. I can't think of another steel used in cutlery with as much tungsten as Maxamet. The cutting numbers from this steel are near the top of the charts. So Maxamet will blow MagnaCut out of the water when it comes to edge retention, but it was designed as a high speed tool steel. MagnaCut was designed to be a "jack of all trades, master of none". Steels like Maxamet require skill and some special tools as a sharpener. It's all about choosing the right steel for the job. Often tradeoffs are involved.

Steel chart - https://www.spyderco.com/edge-u-cation/steel-chart/

I will say that hard, thin knives have a reputation for chipping. Triple B Handmade Blades is a custom maker that focuses on maximizing cutting performance. So he uses high-carbide, high hardness, thin (like crazy thin) edges. You would think that his knives would shatter, but they do surprisingly well in his testing. Here's a short video of Rex 121 (has the highest percentage of carbide volume) heat treated to over 70 HRC. He is performing twisting cuts with a hard wood. At the end, the knife still cleanly cuts paper. You don't see/hear any chipping.

https://www.youtube.com/watch?v=xAPMXGvrJ1I

Well, I was comparting to/with something like Durit's GD20N [0], which scores 1400 HV30 which should be like 83.6 HRC or thereabouts. It's a WC-Ni powder metallurgic composite with 9% binder. Their website suggests that they make blades for industrial paper cutters, but I'd assume those use normal WC-Co due to paper not being particularly corrosive.

Sure, the geometry matters a lot, but that's also fairly orthogonal from the metallurgy.

[0]: https://www.durit.com/en/technology/carbide#c1340

That's an interesting material. I'm not a knife maker so I can't really answer your question. I would imagine that this material would, initially, pose a problem for large-scale production. You would have to learn how to work with this material as it is not steel. Their current set of tools and techniques probably won't work well with a fundamentally different material.

If anybody were to try this, I would suspect that it would be easier for a customer knife maker to do so. Kase Knives[1] has messed around with elastic ceramic before. He's always pushing boundaries. He might try something like what you suggested.

It would be incredibly expensive though. I wonder if you could laminate some slabs of mild steel around a carbide core. This is done with steel all the time (especially in Japan). Not sure you could do this with steel and carbide though. You only really need enough carbide to form the apex. The rest of the blade stock is there for lateral strength.

[1]https://www.kase-knives.com/home/english/

Great looking knife, but 10 minutes of looking doesn't reveal where to buy one!

The first batch was given to smaller makers, often custom makers. Right now, Tactile Turn is offering a couple knives in MagnaCut (change the option in the drop down). I've seen people say they have used up their MagnaCut already. The steel will probably trickle into the market.

Spyderco announced that the Native 5 Salt will come in MagnaCut. No date has been given for that.

https://tactileknife.co/products/rockwall-thumbstud

Imagine spending $300 on a knife.

I can image spending 300 on a kitchen knife, not on a pocket knife.

I have a flash II that I paid about $50 for.

https://carbideprocessors.com/flash-ii-folding-knife-black-t...

It’s lasted me now 3 ish years, I carry and use it daily.

I’ve gone through at least two cell phones in that time. (Three if I count a refurbished one that I shouldn’t have purchased).

If it’s a tool that you use everyday… the daily use cost goes way down.

I used to use Gerber Evos, and Evo JR. They were only about $20, but I could get maximum of a year out of them before they were falling apart and worn out. (Not to mention the pocket clip would often fail, and on a few occasions I snapped a blade…, once just trying to cut a small piece of pumpkin. )

What do you do with a pocket knife every day? Whittle?

For real. I have a tiny swiss army knife that cost like $10. I use it to open packages, and I keep it in my pocket's pocket. (You know, the little flap thing that's in your right pocket for storing loose change or whatever.)

Carrying around a knife that large seems miserable. I already wince when I wear pants that don't have a pocket-pocket (lol, I should probably find out the actual name). Carrying around a 4.5" knife is like ... why? Where do you keep it?

The little pocket on the right side of many pants is called the watch pocket. It was originally used to carry pocket watches. Because people don’t commonly carry pocket watches anymore it’s not as big as it used to be.

Coin pocket https://www.heddels.com/dictionary/coin-pocket/

> I should probably find out the actual name

It's called a "watch pocket", originally meant for, unsurprisingly, pocket watches.

Snap it to the back of your pants or your belt. Most knives have a clip.

Carrying around a knife with a pocket clip… you won’t even feel it’s there. I also have a leather man wave + in the same pocket. I sometimes notice that.

It’s more comfortable in Jeans vs dress pants, but both work.

Cardboard, cable, carpet, drywall, twine, plastic packaging and tape, letters, tags on pet toys, pillows, - a good knife made of a modern super steel can be a revelation. Get a good one and keep it handy, and you'll find situations daily where it genuinely makes life easier. For tech people, something like Leatherman skeletool is the ultimate every day carry because of the multi tool, and you can buy custom blades made from powder steel.

Availability is hit or miss though. I've been trying to find an improved MUT blade for years.

Open packages, cut boxes… various projects. Strip wires in a pinch. Improvised tool if one of the motorcycles I own from the 1980s breaks down.

I do also commonly keep a leather man wave + in the same pocket.

Other pocket tends to have car key, chapstick, streamlight, and a mala.

Edit: I will say I’ve brought the flash II with me to at least 5 countries, and have used it to also once cut some chambira while on a boat on an offshoot off the Amazon river.

I take it you have a holster for your phone?

No, phone usually goes in my back left pocket, or left pocket of my sport coat if wearing one.

$300 is peanuts.

Some of the high-end Japanese knives go for thousands.

That’s a nice knife, the spiderco looks pretty shitty in comparison

Spyderco takes pride in their knives looking ugly. They're totally form over function. Comparing the handles, I'm pretty sure the Spyderco would feel many times better in my hand. Also, they have amazing fit and finish, and come razor sharp from the factory.

An expensive brand, to be sure, but I have only good things to say.

How do you sharpen those serrated blades? I get function on serrated but I don’t really want a 150$ + knife to be disposable because it can’t be sharpened

It's tricky. Typically you get thin rods and do each serration individually. Spyderco sells their "Sharpmaker" for this. It's a bit overpriced; you can find decent substitutes elsewhere.

Generally non-serrated edges are preferable unless you have a special requirement, like cutting rope. That yellow Native is part of their "salt" series for people who work on/around boats and water, and hence need to cut rope for sails, etc. Here corrosion resistance is obviously of paramount importance, which is why they use different steels for "salt" knives. There are also plainedge Natives around, for example: https://www.smkw.com/spyderco-native-5-lghtwt-blue-frn.

I was giddy over this article regarding the corrosion resistance. Was just eyeing a custom benchmade 20cv for a high saltwater exposure usecase; hoping this metal makes its way over there as well

The post is more about the steel than the knife. The steel is quite new to market, so not many knife manufacturers have picked it up yet. However, here's one I found for you.

https://www.knifecenter.com/item/SP41SYL5/spyderco-native-5-...

Dawson Knives have numerous models:

https://www.dawsonknives.com/collections/home-page

I wonder how MagnaCut compares to INFI. I've seen knives made of the latter do things I would've considered flatly impossible.

Elastic ceramic is a pretty wild material as well. You can do stuff with it that seems impossible with steel.

Where can we buy magnacut knifes? (for cooking if possible)

This knife enthusiast[0] implies that this steel isn't necessary in the kitchen

Though I had the same question, I'm guessing it'll be a few years and it'll be very expensive.

[0]https://news.ycombinator.com/item?id=29697285

Spyderco already announced MagnaCut in their 2022 catalog. However, they are backed up at the moment. I am not holding my breath for a release in the near future. Custom makers tend to be on the cutting edge (no pun intended) when it comes to using "odd" steels. I expect more and more people to use it. That said, will Crucible make enough for demand? There's not a ton of money in knife steel production. Right now, Crucible's latest cutlery steel is S45Vn. S35Vn and S30V are still widely used as well. 20CV has taken off a bit too. I don't think Crucible will start making large batches just yet. But, I could be wrong.

I'm sure this will get down voted as its a Luddites call to arms, but all my cutlery is simple high carbon steel.

Its cheap, holds an excellent edge, and in the kitchen it develops a wonderful rustic patina. For a pocket knife, a few drops of oil once or twice a year will keep it in good order, or you can chemically blue it if that suits your style as well.

any recommended brands? or are these custom made?

Spyderco, but I am a fanboy. Their forums are really insightful. If you do down the rabbit hole of knives and steel, Spyderco does a better job of catering to this market. They experiment with all kinds of steel that will never make it to another production company. It should be noted, Spyderco knives tend to be on the "ugly" side. It took me a while to get them as a company.

Benchmade, Hinderer, Chris Reeve, Spartan, Demko, etc. The list goes on and on. This is a great time to be a knife knut.

> This is a great time to be a knife knut.

Curious as to why is that?

Intricate knives requires high precision manufacturing. There are lots of small makers out there. Sharp By Design[1] is a one-man knife shop. He operates a CNC machine out of his garage in New Jersey. while his designs may not appeal to you, he puts a lot of time and effort into his knives.

But his knives are expensive. He can only work so fast, and he has to charge a living wage for his time. Many people will scoff at paying several hundred dollars (perhaps over one thousand) on a knife.

The rise in high-precision manufacturing in China means that Sharp By Design can partner with Reate (a well known Chinese knife manufacturer who does very good work) and offer his knives at a much more affordable price. He doesn't have to simplify his designs either. Other Chinese companies like We and Kizer are doing similar work. More and more custom knife makers are getting a deal with a company that allows their designs to be purchased by more and more people.

Hell, there are people who are making a living as a designer partnering with Chinese manufacturing. They don't have the knife maker background. They have a good eye for design and understand the market.

Thanks to Larrin and other prominent knife people, knife users have a better understanding of knife performance. We now know that geometry and hardness are important. Companies are slowly responding, Companies across the board are upping their game. Civivi (owned by We Knives) makes budget knives. Their quality, fit and finish, and steel choices are great for what you pay. You don't have to spend a lot to get a good knife. Everywhere you look, people and companies are getting better and better at making knives. Titanium used to be an exclusive material. Titanium frame lock knives are everywhere, and they have a price that is not prohibitive.

Finally, Triple B Handmade Blades (Big Brown Bear on YouTube) is importing some of the highest quality diamond stones (not aluminum plates, but actual resin-bonded stones) available. They are very pricey (start at $350), but they allow you to easily sharpen high-hardness, carbide-packed steels.

[1] https://www.sharpbydesign.com/

The thing is, there's no such "best" steel. It all depends on what you want to do with the steel. I'm sure a custom maker will make a MagnaCut chef's knife, but I don't think you'll notice much of a difference. The corrosion resistance should be great, and that goes a long way with easy of maintenance, especially when cutting things like tomatoes. But most kitchen work is done on a cutting board (hopefully plastic or wood), and the material is quite soft. You can make a good argument that MagnaCut isn't needed in the kitchen.

MagnaCut wasn't developed for the kitchen. Even though I am a self-professed "knife person" I just don't rely on a knife all that much where I would notice the difference between MagnaCut and VG10. So, on paper, MagnaCut is a big step forward compared to pretty much every steel. But that doesn't mean every steel is not obsolete. And, of course, we all have preferences. We like what we like, even if another option is "better" in some way.

52100 is a great steel. Sharpens like a dream. Sometimes, that's all that matters to a person.

A (probably) completely different question: are there good knives for a kitchen that doesn't require maintenance? (So, are the ceramic knives any good?) I cook once in a blue moon, mostly pasta; so I'd use it mostly to cut cheese and sausages. Can you recommend a knife for this? (Or maybe it simply doesn't matter on such a small scale?)

No, there aren't. Knives dull over time; even the most durable steel formulations need sharpening eventually. Those ceramic knives are pretty robust, but they too will dull. More importantly, they're extremely brittle; my experience with them is that they chip very quickly and are really unsuitable for anything other than very light use. For your use, they might be ok, but I think you'd end up being annoyed when they break sooner than you want.

I recommend something from the Victorinox Fibrox line to folks like you who just want to cut stuff and not think about knifes. They're very sharp out of the box, quite durable, and will last a long long time before going dull. When they do, they're so cheap (like $25) that you could just get a new one rather than messing around with sharpening.

Those $6 tools with the three grades of sharpening V’s work well enough to make a $25 knife last fairly indefinitely in this particular use case.

Although beware, those pull through sharpeners are notorious for doing a terrible job sharpening knives. They take off far more material than needed and tend to produce an edge that isn't very sharp. YMMV.

I’m aware.

The context here is someone who does little cooking and just wants a sharp knife three times a year.

A remotely-decent stainless kitchen knife on non-fiberous materials will last long enough that you don't really have to worry about it. Especially for such soft materials as cheese and sausage.

Vegetables are the problem for sharpness, and meat-with-bones the problem for toughness, assuming careful handling. So, yeah, with care to not bend it, a ceramic blade will do well on things like carrots, while a simpler stainless steel blade handles your cheese and sausages just fine.

But even then, a very simple high carbon blade with a simple automatic-angle-keeping sharpening tool (10~20$) only needs to not see the dishwasher and receive oiling before storage. Which is basically the extend of "have an oiled sheath to store the blade in". French Opinel makes cheap (5~15 $) (but rather practical) pocket knifes out of (traditionally) such carbon steel. The wooden grip is more sensitive to water than the blade, in my experience.

Any cheap or expensive knife that comes with one of those sheaves that have the sharpener built in will probably work well for your circumstances.

I have a $5 rectangular chef knife that I got in Chinatown. I'm sure knife nerds would consider it crap, but it works fine. I have to sharpen it now and then. Dunno if that counts as maintenance. The simplest way to sharpen a knife is with a slack belt sander. I don't have one of those so I just sharpen it freehand on a cheap stone. No idea what I'd do with a fancy knife if I had one.

When I think of maintenance, I think more about corrosion resistance. Is the knife 100% dry when I put it away? Do I want to take the time to wipe down the blade when I cut acidic food items? Then I think about sharpening. How long can I wait between sharpening? How long must I sharpen the knife? VG10 is a good knife steel for the kitchen. It is a Japanese stainless cutlery steel. You can find this steel on mass produced knives (Tojiro) and on many custom knives, which can be quite expensive. VG10 has good corrosion resistance, decent toughness, sharpens well, and can hold an edge a decent amount of time. An inexpensive combination King water stone is up to the task of sharpening VG10. It also does not take an inordinate amount of time to sharpen VG10. As a comparison, Magnacut will do everything VG10 does but better.

Another benefit of VG10 is that you often find it in knives from Japan. They understand that geometry cuts, so they tend to use thinner blade stock (but their knives are not brittle) and they tend to heat treat to 59-60 HRC. I think these knives are a good all-around package. Again, Tojiro is a good brand to start with.

I have a self-sharpening stainless steel kitchen knife made in Czechoslovakia with waved edge. It never sharpened, but it still works just fine for everyday kitchen needs, except for peeling (I have a ceramic peeler for that), because of the waved edge. However, I have no idea where to buy a second one. «Bread knifes» with roughly similar edge are large, thick, and non-flexible.

I have family members who refuse to clean knifes properly. I need stainless steel. Personally, I'd prefer to have high carbon, but I know it'd be a rusted mess in a month.

I've had great success with Victorinox stainless steel knives. They are pretty sharp, for us anyway, and seem to keep that way. And, they seem to be pretty reasonably priced.

So is this getting us any closer to making a knife I can regularly put in the dishwasher, or are we still limited by the technology of our time?

I put my Victorinox in the dishwasher with no ill effect. The biggest danger is when a visitor decides to chop a tomoto on a ceramic plate.

It's no Japanese chef knife, but a bargin for what it is.

I have a nice set of Japanese chefs knives, and still use my victorinox on a regular basis. it's hard to argue with being able to drop it in the dishwasher.

my 8" victorinox will be 8 years old in march, and is still going very strong, quite the bargain.

I read that Victorinox regular tests their knives with a dishwasher. While knife people will cringe at this, to many a knife is but a tool. When the tool is dirty, throw it in the dishwasher with the other dirty kitchen tools. Makes sense, but I'd never do it.

The best part about the Victorinox line of knives is there handles. You can't ruin them with the dishwasher. Wood and other natural materials don't fare well in the dishwasher. Their steel (note quite sure what it is) is very corrosion resistant as well. It holds an edge long enough, and it is easy to sharpen. If you are a "knife is a tool" kind of a person, go with Victorinox.

Why? It literally takes less than 15 seconds to clean and dry a stainless knife.

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