"The benefit to magnacut is that it matches the toughness and wear-resistance of non-stainless steels like 4V and therefore puts us in a new category for stainless steels. It can be heat treated to higher hardness for enhanced edge stability for more acute edges, better cutting ability, and better edge retention without sacrificing toughness when compared with previous stainless steels, or kept at a more conservative hardness when raw toughness is desired." - 11:33 This is an important quote to me in this video because there is this prevailing myth going around that MagnaCut is tougher at it's maximum hardness, as if there is any steel where you get something for nothing.
Great video, both in content and in tone. I think your modesty might be preventing you from emphasizing how much of a game changer this steel is (basically the first hypereutectoid stainless to eliminate chromium carbides). Makers need to be explicitly told that this stuff escapes the toughness/hardness tradeoff parameters of the high-alloy stainless steels that they are familiar with.
Customers actually use them and have something to compare too? I just don't like to hear that the customer is happy when more than half don't use them or use them in such a weak capacity that they would have been fine with 14c28n or whatever. I just don't like this argument that you used. Cause it doesn't have any data and is used to shill for someone.
@@tacticalcenter8658MagnaCut at 62.5 is going to be better than pretty much any other stainless steel out there, save 14C28N for pure toughness at that hardness, at the loss of a lot of wear resistance. 62.5 vs 64 HRC is only 8.2% harder. 60 to 64 is 21.1% harder, and that's where I'd draw the line at being significantly better. A 12c27m or 420hc knife at 56 HRC compared to a 64hrc steel would be a difference in hardness of 40% more, plus much greater wear resistance carbides. That's when it really feels super.
I feel fortunate to be making knives when there is so much quantifiable information regarding HT for each steel. Compare our knowledge level today to what was known when "Practical Blacksmithing" was published over 100 years ago, and you will thank every Knife Steel Nerd who advanced our community knowledge base. Thank you, sir!
Amazing that some steels made centuries ago still measure up, but the proprietary information stayed with families, not corporations, and some formulas stayed the same for several decades and reasonably near the original for centuries. Kind of feel like mass production essentially killed that, but glad to see small batch production runs making a comeback.
I have your book and it changed a lot of misconceptions I had about HRC, tuffness and edge retention. Reading it is like drinking from a fire hose so I have reread it here and there it get it to stick in my head. It’s the kind of book I love with high information density and not a lot of fluff I would highly recommend this book to knife makers or anyone who wants to get a good grip on the steel industry and specifics on the steels available.
For real, this book is so informational, I cant believe the value:price ratio it offers. I'm learning so so much from it in terms of practical knowledge. Amazing.
Every one of those articles on knife steel that aren't one of Larrin's In some cases they also seem AI generated off of other ones, they're so inaccurate. Things like D2 being said tougher than 14c28n, when they couldn't be further from the truth. @@jeffhicks8428
Man, my nerdy brain was massaged with so much technical information. I love this and getting a little more understanding, even if I’m don’t make or work with a knives.
Thanks for helping dispel the current trend that people think magnacut is trash unless the rc is 63-64. That simply isn't true. Too bad some people don't listen, even when I site your information 🤦♂️.
I know you like to stay objective, but it’d be the Cherry on top for you to layout at the end applications for different HRC’s. Example: For a moderate use folding knife X heat treatment + geometry I think would be ideal because ____. I realize you’re a metallurgist not a blade smith, but as someone who is neither, that’s something I’d enjoy. Great video, can’t wait to get some Magnacut in my hands
What Cedric & Ada demonstrated in with the Spyderco Magnacut Mule was unbelievable. I think that's what a lot of people are going to want their EDC knives to achieve. I'm super happy with my outdoor knives in Cruwear.
You could, rather trivially I might add, make a knife in a low edge retention high toughness steel like AEBL that could score in a similar range to 10v on his "edge retention test" if you gave it suitable heat treat and geometry for the very specifically odd task of being able to slice a lot of abrasive rope and still being able to cleanly slice copy paper. BUT. if you had to select the best steels to use for a such a test, Magnacut is right up there. Anything that can get hard enough to take a nice thin geometry and still be tough enough to resist clipping.
What a great time to be a pocket knife enthusiast! You’ve tipped the scales with Magnacut. Nothing else will ever do until Magnacut 2! My Sebenza Small 31 and my Pro Tech Runt 5 are both Magnacut! Thanks for your work!
Not sure about Magnacut 2, but for sure variants which offer a different balance are likely in the future. The EDC world would likely be more interested in a higher edge retention variant whereas the OG has the kind of good toughness at high hardness that comes as a premium in high performaing kitchen cutlery (at 64 rc it's as tough as AEBL, with much more edge retention) and a toughness necessity in hunting type knives with the added luxury of being highly resistant to corrosion. Small little pocket knives do fine with lower toughness steels stuff like m390 which is what I'd suspect the next variant of magnacut will likely be about.. That's what the end users want, they're all overly obsessed with "edge retention." RIP to m390.
I have a magnacut outdoor blade at 62.5-63 hrc and a chef knife at 63-64 both perform very very good. Couldnt be more happy with magnacut especially when seeing how thin i can take the edge. My chef knife is 5-8 per side to 10-16 inclusive and has not had any problems at all. My outdoor is around 15 per side and has not has any problems either
I had been waiting for a response like this after seeing several posts and videos on the matter. Thanks for dropping the education and dispelling the myths.
It always amazes me how some people who just don't know; well , you just can't tell 'em.... Even if you developed the steel and have tested it extensively... and have the best of interest in the success of it. Truly remarkable.
Case Western materials engineer here…great video. Couple questions - 1. What is the mechanism that allows room temp stabilization of austenite? What is changing that prevents it from transforming during a cryo treatment to martensite during that lengthened time? 2. What is the process of increasing hardness during the secondary hardening (like you mentioned in the coatings part), is it just the formation of addition carbides like chromium carbides that adds to the hardness? I always knew that to be the sensitization range for stainless’ but never attributed it to increase in hardness as well, but it makes good logical sense. Just seeing if there’s any more details there. Thanks much! I just got a CRK Zaan in Magnacut and am absolutely loving it so far. It really is in a new space in the stainless knife world.
1. Retained austenite stabilizes at room temperature due to carbon diffusion to the austenite-martensite interface. Here is a paper on it: www.sciencedirect.com/science/article/pii/0921510795030174 2. Secondary hardening occurs through the precipitation of alloy carbides, especially Mo, W, V, and Cr. Here is an article I wrote on tempering which summarizes this behavior: knifesteelnerds.com/2018/04/23/what-happens-during-tempering-of-steel/
Such great information. I love learning this stuff. My dad was a metallurgist, so I feel my like for this field is in my blood not to mention I worked in engineering most of my life. The only thing I'd alter in producing at least this video is, your voice sound level is competing with your background music sound level and the music sound level is distracting attention to what you're saying. Speaking as a school teacher with a BS in education, I'd either lower the music sound level or get rid of it.
Thanks for taking the time to put this video up great amount of information I kind of had it figured that most production company's were going to be in that 60 to 62hrc for the toughness aspect and only in customs were you going to have that 63 to 65hrc and at a thinner geometry that I personally tend to like but that is preference as you mentioned. Thank you again for the video tremendous amount of helpful information.
This is likely the single most dense, thorough, informative, fact based and useful/helpful, well thought out video on the whole general topic of knives, steels, edges, cutting geometry and all that jazz. Speaking of jazz I'd guess the soundtrack was deliberate and that was fantastic as well. This video is a metaphorical mic drop on an ecosystem that was struggling with rational and empirical deficiencies for a long time coming. If I ran a knife forum, which I don't because I'm not only lazy but also not a masochist, I'd mandate every single user to review the contents of this video as many times as they needed to in order to pass an examination before they could comment on certain topics. I'd bet that cut down on mod time quite a bit.
Would love to hear your take on 1. the factors going into a knife with the longest lasting fine edge, and 2. an explanation of what underlies the bitey, sticky, crisp, or whatever term you choose edge that is spoken of often..
Basically, you go for the thinnest angle you can that holds up to your cutting tasks before it starts dulling by chipping or mushrooming. Harder steels resist mushrooming and toughness prevents chipping. Bitey edges are caused by using coarser stones because the burr breaks off as it forms, so you end up with a micro serrations from longer and shorter burr pieces even with a perfectly removed burr on a coarse stone, finer stones can get less and less edge variation, which are smoother and less bitey, even though capable of being as sharp or sharper, which deals with his easy cut initiation is like in hair, but coarse edges might cut much better through real foods when slicing motions are added, whereas absolute sharpness is for push cutting without a slice. Imagine slicing a piece of raw meat versus pushing straight down through it, you need a sharper but less bitey edge to do the latter.
the retained austenite part might be why I find my 20cv knife relatively normal to sharpen rather than difficult, maybe it was just a good heat treatment
Great video! The only thing it lacks is a bit of historical perspective that shows just how extraordinary these new steels are. It was only a decade or two ago if you wanted toughness, you had to deal with rust, and 62 hardness for production knife blades was only possible with high-speed steels. Now, we have a slew of incredibly balanced performance steels that offer what used to be the ultimate in every performance parameter. Now we have a steel that provides 63-64 edge wear in its "SWEET SPOT" for toughness, AND its stainless! You have to have loved a knife made of 52100 or 440C, to really appreciate these new steels. They are incredible.
One of the best informative knife vids out there. Well done Mr. Thomas. This is a great summary of parts of your book. I gave sharpening and knife info lessons yesterday and this would came in handy to explain a lot of the topics I talked about. I work for J.A. Henckels and would love to bring this info into the laboratory in Solingen.
Uhh that's awesome! I'm a zwilling man. Have a kanren chef knife on order right now. I have a question if you don't mind: do you research blade geometry, such as flat vs full flat, convex, s Grind etc? This seems to be a highly neglected area for kitchen knives.
Greatly informative video on the complexities of blade steels and the many (MANY) variables that affect performance. Thank you for sharing your wisdom. 🙏
Crucible Industries cuts blanks for knife makers and they do the heat treat too. So much of the semi custom market has perfect heat treating in these boutique steels. Bark river comes to mind.
I do wish Bark River would treat their Cruwear knives to over 60 HRC (maybe 62?). It seems like at 60 HRC you'd be better off sticking with 3V, but maybe I'm still missing something. I probably need to find better graphs comparing the two with overlapping hardness - I just hope they're not being too conservative with that one.
Really useful, informative video. Thank you. One suggestion: the serious, edgy jazz in the background makes it significantly more difficult to concentrate on your words, especially when things get technical.
Very nice of you to take time to talk about the subject. I find the So called supersteels in certain tasks useful, they are good to have if skinning game for example or cutting meat large amounts. Still far north the climate is unfortunately during harsh Winter - 22 to - 58 Fahrenheit. - 30 to-50'Celsius cold. The toughness and strenght of the blade is more relevant in extreme cold conditions because the blade become brittle and snaps easily if the steel is not able to bend and withstand blows while chopping wood with a Leuku. The construction of a puukko differs also from a full Skeleton fulltang knife which is something to keep in mind. You dont want to Touch metal when the Temperature drops to minus 30' - 50 Celsius. The skin sticks to the metal and rips youre skin off youre Fingers and the palm of youre hand. The wooden Cover also insulates the long Tang inside the handle. If the puukko is made with old traditional methods, the whole Tang goes through the handle All the way. Its pretty useless to try to explain how its done and I havent talked to anyone who knows that there are others besides me who does it the long and very time consuming way to it by hand. When its done properly I keep them all myself usually, sometimes I give one for Christmas as a present for my family and dear close friends. The whole process takes 3-5 months. Selling any of my fulltang puukkos has not crosses my mind. Its just too much work for to be Sold. So I choose very carefully the knife steel because the all materials are the best there is and I dont spare any expences ever. What I do worry is that if I would use some New supersteel it would be a skinning knife or puukko. If I make a puukko for General use it has to actually work in all weather conditions hot or cold or moist. The usual steels are tougher steels like Aeb-L, 80crv2, 14% chromium steels, now I have been considering making a puukko from 15n20 steel. If the conditions are extreme cold its not an option to choose supersteels that have not been tested in real life situations for atleast 6 months preferably a year. Just the time used in making a proper puukko takes so long that local puukko Masters dont choose to use new steels because the older basic steels have a long succesful rate for surviving in dead cold conditions without breaking, decades. I kinda am interested if the So called supersteels have any Chance of performing better? The thought that Magnacut or Elmax would be better is naturally been laughed at by national knife makers. I understand the sceptism, but I if Magnacut puukkos are never tested during Winter time, no one really knows, does the blade survive or not? It would need to survive winter Batoning firewood and skinning large game, opening cans, making fire, food prepping, wood work. I have been thinking that this would be a real life science project, I have been trying to find a Magnacut blade with a fishtail Tang without succes. I wonder if there would be a possibility even in theory that Magnacut would survive a winter test if heattreated 59-60 hrc and made a blade suitable for a leuku, fishtang as long as 13-15cm with a 180mm cutting edge if the thickness would be 3,5 to 4,2 mm? And 40 - 47mm tall blade? It would be quite fun to prove wrong the traditional puukko artesans. I wonder if there would be suitable Magnacut blade for this project?
What you said at the end of the video is key. I first thought to myself when I saw that White River had a special run of the M1 knife in Magnacut at 59-60 Rockwell, that that's way too low! They aren't anywhere near the wear resistance/toughness sweet points for this steel. Then I watched this video and it is what you say, as long as they have taken the proper steps during heat treat, it should end up being a tough and (truly) stainless steel.
That's way too low for Magnacut I would rather have a good Cruwear at 63_64 I just don't understand why all makers can't get the Magnacut right across the board
@@sterlingstoots3215 You know more than the maker of the steel? Who just said, in this video that you're commenting on, that 58-60 HRC on magnacut is still good? How it got there is more important than what HRC it lands on
I think the issue is that we can never really know if a heat treatment was good or not. Hrc is just a tiny indicator. But if something is outside of the expected range, the chance is at least higher that the heat treatment is not optimal.
While experience is valuable, it doesn't take long before you realise that just because someone sounds convincing, they might not actually understand why what they are saying is wrong. Meaning, I very much appreciate your evidence based approach to these subjects. I find the data itself as interesting as its application to actually making knives. Cheers mate
For some reason TH-cam likes to auto play this video for me and every time I end up watching or listening to it all the way through. That said, each time I pick up something new that I missed before. I know the videos are a lot of work for you but man Larrin they are valuable either as a stand alone or more so when paired with all your other work on the site! Furthermore, I’m really enjoying the new book!
Love this video and love this channel! So much easier to understand the science of all things blade steel when its video form and the metalurgist is laying it all out for us
Cork (Cork Trivet) sprinkled with wood fie white-ash foxes Edge-Apexes in the field… tooth paste sprinkled w. baking soda polishes the works… warm Tea-Tee oil protects fro oxidation (binds to the steel
Old habits die hard in every industry. When I worked in the automotive industry I talked to so many guys who thought that newer oils like 0w-20 or 0w-16 oil were too thin for any car and couldn't be trusted even when it was the specified oil for a given car.
I was on the fence about getting the launch 15 because almost everyone that talked about it ultimately criticized the 60-62 hrc as a deal breaker and I was partly dissuaded because of this but hearing this info from the man himself puts me at ease
I'm excited to say I recently picked up a white River fc3.5 in Magnacut. It's at a 61-62 RC, and I'm eager to put it to work. So far, I'm impressed with it. I've profiled it to 18.5 degrees per side.
I had already learned a lot of this by reading a lot of the information from Knife Steel Nerds, but this video puts it all together very well. Its a LOT of information to process, and the video presents it in a way that's easy to digest. My knives are primarily cutting tools. I use them to butcher and process wild came and fish, and I don't beat on them or use them like a cleaver. That said, I STILL don't know what steel, hardness, and angle would be best for my needs. Seems like something like I should be able to go with a high carbide steel with high hardness and an acute edge since I'm basically slicing meat. I'm just not sure at what point microchipping would become an issue.
Best to just try! If it chips, sharpen it a tiny bit more obtuse. It doesn't take much. 2x thickness is 4x the strength! Just pick a good all-rounder stainless steel and you'll be real happy. Even 14c28n would probably make you happy with a good grind. But this Magnacut is the top Jack of all trades knife steel. It can be super hard, really tough, and is good for wear resistance at the same time and totally stainless. But even a cheap soft knife can take more acute angles than you'd think!
Thank you for the video! You’re doing your best to keep all the miss information at bay, and you are the best man for the job! This video is packed with tons of info, I’ll definitely be watching this video more than once.
Thanks for the video, Larrin. What excited me about Magnacut in the first place was that it seemingly could function as a stainless replacement for 4V/Cru-Wear-type steels. I'm sure Magnacut at lower hardnesses isn't bad, but I'm not very interested in it at 60/61 HRC and wouldn't want 4V/Cru-Wear at that hardness either.
Would make a hell of a machete, but most aren't making competition choppers in those steels either. Kitchen knives or EDC can go pretty hard. That being said, you can put thinner geometry than you think on even shit steel like 54hrc 50CrMoV15.. if you're careful about it not clanging against anything ever, only the cutting board and food.
Hardness is an exponential scale, Rc 60 to 61 is a gain of 5% hardness, 50 to 51 is 4%. Rc 60 to 62 is 10.3% harder just in case anyone was wondering. Oh and cheap companies who HT 14C28N which should be at Rc 62, but they leave it at 57; Rc 57 to 62 is 24.7% they're leaving on the table.
Across the typical hardness range used in knives, the correlation between hardness and strength is effectively linear. See the chart in the article comparing compressive yield strength between REX20, 52100, and 440C, for example. I wouldn’t get too hung up on the exponential concept.
@@KnifeSteelNerds I don't, especially when it is so small. It is like buying new tires that are slightly bigger than your speedometer is calibrated for, the higher you go the more the difference even though it isn't much.
Love this vid... and confirms that my loved AEB-L is awesome... I mean, sure, it has lower edge retention that the hi tech steels, but the hardness and thoughness are up there, and it cost 1/5 of the fancy steels Take a Like
Great information. It's also why I refuse to buy any non optimally heat treated Magnacut out there. Also, the arm and a leg they trying to charge us for it.
I had a question I have a few knives in cromax pm, I am not sure about this knife steel and can’t find any information on it. I figured if anyone would know it would be you. Thank you so much for the amazing videos and your work in knife steel.
with the megapixel Wars it was/is worse than just optics. smart phone camera sensors they often just blow up the outputted scan; like upscaling a smaller photo in photoshop, [or hardening steels to the detriment of toughness]. So your comparison between cameras and HRC is brilliant. lol
This video is amazing. It explains a lot of complex ideas (to me the noob at least) in an easy to understand way. Great usage of visuals to support the data as well. Thanks!
I love your explanation. Magnacut has been a great steel so far - tested on a lionsteel M4 with regrind. Also dig your taste in music - grim fandango ost ftw!
Hi Larrin. Question about Magnacut heat treat warping. There seems to be a huge amount of warping with Magnacut heat treat as experienced by Gary Creely and other knife makers. Do you think there is something specific in Magnacut causing this, or perhaps heat treat companies making mistakes or just having teething problems getting used to Magnacut? Second question, what are your thoughts about using a carbide peen hammer to straighten hardened and warped Magnacut at room temperature. Surely there would be a good chance of causing micro cracking? Thanks for your videos. Always great info.
Amazing stuff! Would you say that 61-62 HRC MagnaCut is currently the optimal jack-of-all-trades steel for an allround knife that would be used for both survival, bushcraft and hunting?
This video would have saved me so much misconception when I was younger. I knew most of this stuff (except for the waiting factor/austenite stabilization before cryo), but that's because I lurked Bladeforums for a decade, did cut tests, and got an mse degree. This will help so many aspiring knifemakers.
As someone new to this it’s extremely frustrating. It really means that the steel doesn’t matter since every manufacturer can change it so easily. Magnacut and everything can be completely different when purchased from different manufacturers
I've reached saturation. I bought Knife Engineering way before The first research smelt of CPM Magnacut. S35VN was my favorite. I hated S30V and D2 and thought my preferences were dialed in. This last Summer I got Mule Team in SPY27 and Magnacut. I am by no means a steel snob or even a complete nerd geeking on alloys because there's so much more to think about, availability to say the least. My Condor Wayfinder is great user, but I put it in a log stump point first one time and broke one or two mm of the tip without a fast sinking or hard push and zero flex while doing it. So I can cut most of what I want and my knives hold up, but wanting to see remarkable or measurable improvement I study. But now I have two much information to decide and process. First I give up on one knife doing it all. No one steel, thermal cycle protocol or blade geometry would do over 70% of a days tasks and then there's the days of carrying the knife but not using it that day. I guess I'm thinking of the other people whose knife can do more than any of mine and I don't want to miss out on anything! My fantasy is having a fixed blade knife and sheath system where I can cut tomato, cut a tin can to make it flat to patch a structure or cover a hole, open a six foot chain link fence, create an entry in a steel building wall and chop Barb wire line. I guess just wanting the balance that Magnacut has the most of WITH corrosion resistance is not going to answer that fantasy. Knives, nay I, myself cannot do everything I want till laser swords are affordable. Guess I might list out what I want and prioritize them and look to make that happen.
So, I don't make knives, at least not very often. I do make razors. Razors differ in many ways from knives but mainly in the bevel angle, and the way that the bevel angle is maintained when honing. My razors have a target bevel angle of 16° to 16.5° inclusive, i.e. the angle between one bevel face and the other. The bevel angle is not really end user selectable once the razor has been ground. Because maintaining the bevel angle precisely is more important than exactly what the angle actually is, the spine of the razor is used as a bevel guide. In honing, if the edge is on a stone, then the spine must also be on the stone, and the edge must never touch a stone unless the spine is already landed on it. This is sometimes fudged with the use of electrical or kapton tape on the spine but for the most part the bevel angle is fixed by the maker. Razors of course are not used for chopping vegetables or butchering animals or cleaning out dovetails in cabinetry. They are for shaving and that's it. They quickly self destruct when used as knives. My target hardness is HRC60. My HT oven is a Paragon kiln that goes up to 2000°F. This is more than enough for the carbon steels I have mostly used, and the 440C which I have tried but microscopically gave me a usable but underwhelming edge no matter what honing media was used. I had been thinking about trying S35VN but decided to go with MagnaCut instead, and I have a piece big enough for 4 razors, and I will be roughing them out some time this year. So in light of the geometry, and the normal usage of the razor and the extreme sharpness required, I have always found that HRC 59 to 60 works well for me. I do not have a dewar or a convenient source of liquid nitrogen, and have never tried cryo. At most I will probably make one premium razor per week, from MagnaCut or similar. I am quite used to oil quenching from the austenitic state, then tempering twice for two hours at 350° to 375°F. Usually the blade is ground to shape but the edge left a minimum of 0.020" thick to reduce the number of blades that crack or warp in quench. With plate quenching of Magnacut I anticipate NOT hollowgrinding the blade until after complete heat treating, to maximize quench effectiveness. I am concerned that the small contact area of a full hollowground razor will slow down the plate quench too much. I might try one in room temperature Park 50 quench oil, but I see that nearly everyone making knives, plate quenches or air quenches this steel. So, sorry to go on so long, but I have a question. Should I forego the cryo, for such limited production? Thinking 2000°F austenizing, plate quench, then 2x temper 2hrs at 375°F and then carefully wet grinding to keep the edge cool should give me an excellent blade with good corrosion resistance, appropriate hardness, and very good toughness. If I go 2000F and a nitro or dry ice cryo, and temper down to HRC60, I am getting close to the embrittlement range that you speak of. What are your thoughts, then, on skipping the cryo? And do you think the overall plan is sound? Nice vid, by the way. Very informative.
I have many knives with different steels... by far the S90v stays the sharpest for the longest time... a few strokes on a ceramic stick puts it back to shaving hair...
Wow this video is good. Well done.
Wow, the Nick himself.
"The benefit to magnacut is that it matches the toughness and wear-resistance of non-stainless steels like 4V and therefore puts us in a new category for stainless steels. It can be heat treated to higher hardness for enhanced edge stability for more acute edges, better cutting ability, and better edge retention without sacrificing toughness when compared with previous stainless steels, or kept at a more conservative hardness when raw toughness is desired." - 11:33
This is an important quote to me in this video because there is this prevailing myth going around that MagnaCut is tougher at it's maximum hardness, as if there is any steel where you get something for nothing.
Holy crap it is amazing to listen to people who know in depth what they're talking about.
Great video, both in content and in tone. I think your modesty might be preventing you from emphasizing how much of a game changer this steel is (basically the first hypereutectoid stainless to eliminate chromium carbides). Makers need to be explicitly told that this stuff escapes the toughness/hardness tradeoff parameters of the high-alloy stainless steels that they are familiar with.
There is some serious knowledge in this video, not just for MagnaCut. Thanks for putting all this information out Larrin!
very good, the Magnacut I've made are at around 62.5 RC and I (and the customers) have been happy with this
Customers actually use them and have something to compare too? I just don't like to hear that the customer is happy when more than half don't use them or use them in such a weak capacity that they would have been fine with 14c28n or whatever.
I just don't like this argument that you used. Cause it doesn't have any data and is used to shill for someone.
th-cam.com/video/nwRW-7itYJc/w-d-xo.html
@@tacticalcenter8658MagnaCut at 62.5 is going to be better than pretty much any other stainless steel out there, save 14C28N for pure toughness at that hardness, at the loss of a lot of wear resistance.
62.5 vs 64 HRC is only 8.2% harder. 60 to 64 is 21.1% harder, and that's where I'd draw the line at being significantly better. A 12c27m or 420hc knife at 56 HRC compared to a 64hrc steel would be a difference in hardness of 40% more, plus much greater wear resistance carbides. That's when it really feels super.
I feel fortunate to be making knives when there is so much quantifiable information regarding HT for each steel. Compare our knowledge level today to what was known when "Practical Blacksmithing" was published over 100 years ago, and you will thank every Knife Steel Nerd who advanced our community knowledge base. Thank you, sir!
Amazing that some steels made centuries ago still measure up, but the proprietary information stayed with families, not corporations, and some formulas stayed the same for several decades and reasonably near the original for centuries.
Kind of feel like mass production essentially killed that, but glad to see small batch production runs making a comeback.
Exactly and it’s fun that there’s still much more to learn and discover!
I'm a chemist...and I still struggled...will watch at least 2 more times...sooooo much information
I have your book and it changed a lot of misconceptions I had about HRC, tuffness and edge retention. Reading it is like drinking from a fire hose so I have reread it here and there it get it to stick in my head. It’s the kind of book I love with high information density and not a lot of fluff
I would highly recommend this book to knife makers or anyone who wants to get a good grip on the steel industry and specifics on the steels available.
should be required reading for anyone who wants to talk shop about knives or "steels" online. The mythology in knife land gets tedious asf.
For real, this book is so informational, I cant believe the value:price ratio it offers. I'm learning so so much from it in terms of practical knowledge. Amazing.
Every one of those articles on knife steel that aren't one of Larrin's
In some cases they also seem AI generated off of other ones, they're so inaccurate. Things like D2 being said tougher than 14c28n, when they couldn't be further from the truth.
@@jeffhicks8428
Man, my nerdy brain was massaged with so much technical information. I love this and getting a little more understanding, even if I’m don’t make or work with a knives.
Thanks for helping dispel the current trend that people think magnacut is trash unless the rc is 63-64. That simply isn't true. Too bad some people don't listen, even when I site your information 🤦♂️.
I agree and that was excellent information.
First, great video
-Shawn
I know you like to stay objective, but it’d be the Cherry on top for you to layout at the end applications for different HRC’s. Example: For a moderate use folding knife X heat treatment + geometry I think would be ideal because ____. I realize you’re a metallurgist not a blade smith, but as someone who is neither, that’s something I’d enjoy. Great video, can’t wait to get some Magnacut in my hands
What Cedric & Ada demonstrated in with the Spyderco Magnacut Mule was unbelievable. I think that's what a lot of people are going to want their EDC knives to achieve. I'm super happy with my outdoor knives in Cruwear.
I need a cruwear flipper.
@@anthonycapo1998protec malibu
You could, rather trivially I might add, make a knife in a low edge retention high toughness steel like AEBL that could score in a similar range to 10v on his "edge retention test" if you gave it suitable heat treat and geometry for the very specifically odd task of being able to slice a lot of abrasive rope and still being able to cleanly slice copy paper. BUT. if you had to select the best steels to use for a such a test, Magnacut is right up there. Anything that can get hard enough to take a nice thin geometry and still be tough enough to resist clipping.
What a great time to be a pocket knife enthusiast! You’ve tipped the scales with Magnacut. Nothing else will ever do until Magnacut 2! My Sebenza Small 31 and my Pro Tech Runt 5 are both Magnacut! Thanks for your work!
Not sure about Magnacut 2, but for sure variants which offer a different balance are likely in the future. The EDC world would likely be more interested in a higher edge retention variant whereas the OG has the kind of good toughness at high hardness that comes as a premium in high performaing kitchen cutlery (at 64 rc it's as tough as AEBL, with much more edge retention) and a toughness necessity in hunting type knives with the added luxury of being highly resistant to corrosion. Small little pocket knives do fine with lower toughness steels stuff like m390 which is what I'd suspect the next variant of magnacut will likely be about.. That's what the end users want, they're all overly obsessed with "edge retention." RIP to m390.
I agree, a second version of magnacut should go higher abrasion resistance for edcs. The current one seems perfect for fixed blades.
I have a magnacut outdoor blade at 62.5-63 hrc and a chef knife at 63-64 both perform very very good. Couldnt be more happy with magnacut especially when seeing how thin i can take the edge. My chef knife is 5-8 per side to 10-16 inclusive and has not had any problems at all. My outdoor is around 15 per side and has not has any problems either
May I ask what chef knife you bought? I would love a goof magnacut 8" chef, but I haven't found much.
@@thorwaldjohanson2526 booth are customs 🙂
@@knifesharpeningnorway from what maker? Or did you make them yourself?
@@thorwaldjohanson2526 no from my american friend aaron johnson. He only makes knives for friends.
This video was awesome you always do such a great job explaining everything that in such detail. I will definitely be sharing this video 👌
I love how entertaining this is as well as being very informative. Thanks for all the data collecting and excellent articulation during the narration.
Thank you for breaking this all down in an easy to understand way.
thank you Larrin. Great video
I had been waiting for a response like this after seeing several posts and videos on the matter. Thanks for dropping the education and dispelling the myths.
Thank you very much Larrin. Excellent video that goes well past 'Best hardness for MagnaCut'.
It always amazes me how some people who just don't know; well , you just can't tell 'em.... Even if you developed the steel and have tested it extensively... and have the best of interest in the success of it. Truly remarkable.
As an amateur/hobbyist knife-maker, I love your videos man. Thank you!
For people who have no time to watch the whole video, skip to 29:38 for the summary 😀
Thank you 💯
Case Western materials engineer here…great video. Couple questions - 1. What is the mechanism that allows room temp stabilization of austenite? What is changing that prevents it from transforming during a cryo treatment to martensite during that lengthened time? 2. What is the process of increasing hardness during the secondary hardening (like you mentioned in the coatings part), is it just the formation of addition carbides like chromium carbides that adds to the hardness? I always knew that to be the sensitization range for stainless’ but never attributed it to increase in hardness as well, but it makes good logical sense. Just seeing if there’s any more details there. Thanks much! I just got a CRK Zaan in Magnacut and am absolutely loving it so far. It really is in a new space in the stainless knife world.
1. Retained austenite stabilizes at room temperature due to carbon diffusion to the austenite-martensite interface. Here is a paper on it: www.sciencedirect.com/science/article/pii/0921510795030174
2. Secondary hardening occurs through the precipitation of alloy carbides, especially Mo, W, V, and Cr. Here is an article I wrote on tempering which summarizes this behavior: knifesteelnerds.com/2018/04/23/what-happens-during-tempering-of-steel/
@@KnifeSteelNerds Awesome resource! Thank you again. Hope our paths cross in the future (I’m in the metals aerospace distribution sector).
I have a bark river knife in MagnaCut, i have no complaints, good steel, easy to sharpen and the carbides hold well.
Such great information. I love learning this stuff. My dad was a metallurgist, so I feel my like for this field is in my blood not to mention I worked in engineering most of my life. The only thing I'd alter in producing at least this video is, your voice sound level is competing with your background music sound level and the music sound level is distracting attention to what you're saying. Speaking as a school teacher with a BS in education, I'd either lower the music sound level or get rid of it.
Thanks for taking the time to put this video up great amount of information I kind of had it figured that most production company's were going to be in that 60 to 62hrc for the toughness aspect and only in customs were you going to have that 63 to 65hrc and at a thinner geometry that I personally tend to like but that is preference as you mentioned. Thank you again for the video tremendous amount of helpful information.
Looks like S45VN is a great steel. Seems as though S30V is also a really good steel. Glad I didn’t shit can my old knives!
No steel is truly awful, especially proper knife steels, there's just bad knives.
Bad heat treatment, bad grinds.
This is likely the single most dense, thorough, informative, fact based and useful/helpful, well thought out video on the whole general topic of knives, steels, edges, cutting geometry and all that jazz. Speaking of jazz I'd guess the soundtrack was deliberate and that was fantastic as well. This video is a metaphorical mic drop on an ecosystem that was struggling with rational and empirical deficiencies for a long time coming. If I ran a knife forum, which I don't because I'm not only lazy but also not a masochist, I'd mandate every single user to review the contents of this video as many times as they needed to in order to pass an examination before they could comment on certain topics. I'd bet that cut down on mod time quite a bit.
Watching this video several times and taking lots of notes
Would love to hear your take on 1. the factors going into a knife with the longest lasting fine edge, and 2. an explanation of what underlies the bitey, sticky, crisp, or whatever term you choose edge that is spoken of often..
Basically, you go for the thinnest angle you can that holds up to your cutting tasks before it starts dulling by chipping or mushrooming. Harder steels resist mushrooming and toughness prevents chipping. Bitey edges are caused by using coarser stones because the burr breaks off as it forms, so you end up with a micro serrations from longer and shorter burr pieces even with a perfectly removed burr on a coarse stone, finer stones can get less and less edge variation, which are smoother and less bitey, even though capable of being as sharp or sharper, which deals with his easy cut initiation is like in hair, but coarse edges might cut much better through real foods when slicing motions are added, whereas absolute sharpness is for push cutting without a slice. Imagine slicing a piece of raw meat versus pushing straight down through it, you need a sharper but less bitey edge to do the latter.
the retained austenite part might be why I find my 20cv knife relatively normal to sharpen rather than difficult, maybe it was just a good heat treatment
Great video! The only thing it lacks is a bit of historical perspective that shows just how extraordinary these new steels are. It was only a decade or two ago if you wanted toughness, you had to deal with rust, and 62 hardness for production knife blades was only possible with high-speed steels. Now, we have a slew of incredibly balanced performance steels that offer what used to be the ultimate in every performance parameter. Now we have a steel that provides 63-64 edge wear in its "SWEET SPOT" for toughness, AND its stainless! You have to have loved a knife made of 52100 or 440C, to really appreciate these new steels. They are incredible.
Epic video Larrin. Appreciate all your contributions to the knife-maker community.
U are a TRUE genius in this field of metallurgy... thank you for all u do... but most of all thank you for making it available to the public
One of the best informative knife vids out there. Well done Mr. Thomas. This is a great summary of parts of your book. I gave sharpening and knife info lessons yesterday and this would came in handy to explain a lot of the topics I talked about. I work for J.A. Henckels and would love to bring this info into the laboratory in Solingen.
Uhh that's awesome! I'm a zwilling man. Have a kanren chef knife on order right now. I have a question if you don't mind: do you research blade geometry, such as flat vs full flat, convex, s Grind etc? This seems to be a highly neglected area for kitchen knives.
Your work is a godsend to the steel nerd community 😊
Very informative and interesting. Also a good explanation on why most companies prefer lower hc #'s even if they are doing a quality ht.
Greatly informative video on the complexities of blade steels and the many (MANY) variables that affect performance. Thank you for sharing your wisdom. 🙏
Agreed! PS both my Magnacut knives came from you! I really like your service!
Larrin, you're the man! You make this stuff easy to understand, & you give a lot of info in a short time. Thanks so much for everything you do!
Crucible Industries cuts blanks for knife makers and they do the heat treat too. So much of the semi custom market has perfect heat treating in these boutique steels. Bark river comes to mind.
I do wish Bark River would treat their Cruwear knives to over 60 HRC (maybe 62?). It seems like at 60 HRC you'd be better off sticking with 3V, but maybe I'm still missing something. I probably need to find better graphs comparing the two with overlapping hardness - I just hope they're not being too conservative with that one.
Thanks for the awesome video on this subject, especially the relationship between edge geometry and hardness
Really useful, informative video. Thank you.
One suggestion: the serious, edgy jazz in the background makes it significantly more difficult to concentrate on your words, especially when things get technical.
Very nice of you to take time to talk about the subject. I find the So called supersteels in certain tasks useful, they are good to have if skinning game for example or cutting meat large amounts.
Still far north the climate is unfortunately during harsh Winter - 22 to - 58 Fahrenheit. - 30 to-50'Celsius cold. The toughness and strenght of the blade is more relevant in extreme cold conditions because the blade become brittle and snaps easily if the steel is not able to bend and withstand blows while chopping wood with a Leuku. The construction of a puukko differs also from a full Skeleton fulltang knife which is something to keep in mind. You dont want to Touch metal when the Temperature drops to minus 30' - 50 Celsius. The skin sticks to the metal and rips youre skin off youre Fingers and the palm of youre hand. The wooden Cover also insulates the long Tang inside the handle. If the puukko is made with old traditional methods, the whole Tang goes through the handle All the way. Its pretty useless to try to explain how its done and I havent talked to anyone who knows that there are others besides me who does it the long and very time consuming way to it by hand. When its done properly I keep them all myself usually, sometimes I give one for Christmas as a present for my family and dear close friends. The whole process takes 3-5 months. Selling any of my fulltang puukkos has not crosses my mind.
Its just too much work for to be Sold.
So I choose very carefully the knife steel because the all materials are the best there is and I dont spare any expences ever. What I do worry is that if I would use some New supersteel it would be a skinning knife or puukko. If I make a puukko for General use it has to actually work in all weather conditions hot or cold or moist. The usual steels are tougher steels like Aeb-L, 80crv2, 14% chromium steels, now I have been considering making a puukko from 15n20 steel.
If the conditions are extreme cold its not an option to choose supersteels that have not been tested in real life situations for atleast 6 months preferably a year.
Just the time used in making a proper puukko takes so long that local puukko Masters dont choose to use new steels because the older basic steels have a long succesful rate for surviving in dead cold conditions without breaking, decades.
I kinda am interested if the So called supersteels have any Chance of performing better?
The thought that Magnacut or Elmax would be better is naturally been laughed at by national knife makers.
I understand the sceptism, but I if Magnacut puukkos are never tested during Winter time, no one really knows, does the blade survive or not?
It would need to survive winter
Batoning firewood and skinning large game, opening cans, making fire, food prepping, wood work.
I have been thinking that this would be a real life science project, I have been trying to find a Magnacut blade with a fishtail Tang without succes.
I wonder if there would be a possibility even in theory that Magnacut would survive a winter test if heattreated 59-60 hrc and made a blade suitable for a leuku, fishtang as long as 13-15cm with a 180mm cutting edge if the thickness would be 3,5 to 4,2 mm? And 40 - 47mm tall blade?
It would be quite fun to prove wrong the traditional puukko artesans.
I wonder if there would be suitable Magnacut blade for this project?
What you said at the end of the video is key.
I first thought to myself when I saw that White River had a special run of the M1 knife in Magnacut at 59-60 Rockwell, that that's way too low! They aren't anywhere near the wear resistance/toughness sweet points for this steel.
Then I watched this video and it is what you say, as long as they have taken the proper steps during heat treat, it should end up being a tough and (truly) stainless steel.
That's way too low for Magnacut I would rather have a good Cruwear at 63_64 I just don't understand why all makers can't get the Magnacut right across the board
@@sterlingstoots3215 You know more than the maker of the steel? Who just said, in this video that you're commenting on, that 58-60 HRC on magnacut is still good? How it got there is more important than what HRC it lands on
I think the issue is that we can never really know if a heat treatment was good or not. Hrc is just a tiny indicator. But if something is outside of the expected range, the chance is at least higher that the heat treatment is not optimal.
While experience is valuable, it doesn't take long before you realise that just because someone sounds convincing, they might not actually understand why what they are saying is wrong.
Meaning, I very much appreciate your evidence based approach to these subjects. I find the data itself as interesting as its application to actually making knives.
Cheers mate
Excellent overview not just of Magnacut but it's general considerations for most steels.
Great video Larrin. I especially appreciated the video of austenite forming martensite. Excellent visual!
Awesome! Thank you for providing quality free knowledge 🙏
For some reason TH-cam likes to auto play this video for me and every time I end up watching or listening to it all the way through. That said, each time I pick up something new that I missed before. I know the videos are a lot of work for you but man Larrin they are valuable either as a stand alone or more so when paired with all your other work on the site! Furthermore, I’m really enjoying the new book!
Love this video and love this channel! So much easier to understand the science of all things blade steel when its video form and the metalurgist is laying it all out for us
Cork (Cork Trivet) sprinkled with wood fie white-ash foxes Edge-Apexes in the field… tooth paste sprinkled w. baking soda polishes the works… warm Tea-Tee oil protects fro oxidation (binds to the steel
Love the video!! What you did with the edge impact test is what I was attempting to do on the forum a while back. Thanks for the knowledge.
Old habits die hard in every industry. When I worked in the automotive industry I talked to so many guys who thought that newer oils like 0w-20 or 0w-16 oil were too thin for any car and couldn't be trusted even when it was the specified oil for a given car.
Thanks Dr. Thomas, this was very informative and well made.
I was on the fence about getting the launch 15 because almost everyone that talked about it ultimately criticized the 60-62 hrc as a deal breaker and I was partly dissuaded because of this but hearing this info from the man himself puts me at ease
I'm excited to say I recently picked up a white River fc3.5 in Magnacut. It's at a 61-62 RC, and I'm eager to put it to work. So far, I'm impressed with it. I've profiled it to 18.5 degrees per side.
I had already learned a lot of this by reading a lot of the information from Knife Steel Nerds, but this video puts it all together very well. Its a LOT of information to process, and the video presents it in a way that's easy to digest. My knives are primarily cutting tools. I use them to butcher and process wild came and fish, and I don't beat on them or use them like a cleaver. That said, I STILL don't know what steel, hardness, and angle would be best for my needs. Seems like something like I should be able to go with a high carbide steel with high hardness and an acute edge since I'm basically slicing meat. I'm just not sure at what point microchipping would become an issue.
Best to just try! If it chips, sharpen it a tiny bit more obtuse. It doesn't take much. 2x thickness is 4x the strength! Just pick a good all-rounder stainless steel and you'll be real happy. Even 14c28n would probably make you happy with a good grind. But this Magnacut is the top Jack of all trades knife steel. It can be super hard, really tough, and is good for wear resistance at the same time and totally stainless. But even a cheap soft knife can take more acute angles than you'd think!
Thank you for providing sources 🗡
Thank you for the video! You’re doing your best to keep all the miss information at bay,
and you are the best man for the job!
This video is packed with tons of info, I’ll definitely be watching this video more than once.
Great information! You should consider keeping the background music at a much lower level or use it only for intro and outro.
Saved video for future reference. Very well done
Excellent video! I came for the cutting edge (pun intended) knife knowledge but stayed for the jazz😁
Thanks for the video, Larrin. What excited me about Magnacut in the first place was that it seemingly could function as a stainless replacement for 4V/Cru-Wear-type steels. I'm sure Magnacut at lower hardnesses isn't bad, but I'm not very interested in it at 60/61 HRC and wouldn't want 4V/Cru-Wear at that hardness either.
Would make a hell of a machete, but most aren't making competition choppers in those steels either. Kitchen knives or EDC can go pretty hard. That being said, you can put thinner geometry than you think on even shit steel like 54hrc 50CrMoV15.. if you're careful about it not clanging against anything ever, only the cutting board and food.
Such a valuable source ok knowledge for everyone! Thanks a lot for your work!
Hardness is an exponential scale, Rc 60 to 61 is a gain of 5% hardness, 50 to 51 is 4%. Rc 60 to 62 is 10.3% harder just in case anyone was wondering. Oh and cheap companies who HT 14C28N which should be at Rc 62, but they leave it at 57; Rc 57 to 62 is 24.7% they're leaving on the table.
Across the typical hardness range used in knives, the correlation between hardness and strength is effectively linear. See the chart in the article comparing compressive yield strength between REX20, 52100, and 440C, for example. I wouldn’t get too hung up on the exponential concept.
@@KnifeSteelNerds I don't, especially when it is so small. It is like buying new tires that are slightly bigger than your speedometer is calibrated for, the higher you go the more the difference even though it isn't much.
AEB-L looks great on the HRC + toughness graph at 60-61 hrc. Makes sense my local forge uses it so much for kitchen knives
YAHOOOO WE HAVE BEEN WAITING FOR THIS!!!
Thank you for such a helpful video even for a non knife maker.
Love this vid... and confirms that my loved AEB-L is awesome... I mean, sure, it has lower edge retention that the hi tech steels, but the hardness and thoughness are up there, and it cost 1/5 of the fancy steels
Take a Like
A lot of great information!!!
As with everything,,, it's always a balance!
Great information. It's also why I refuse to buy any non optimally heat treated Magnacut out there. Also, the arm and a leg they trying to charge us for it.
Thank you Larrin. This video is amazing
I would love to see a study of how big of a difference in edge stability does 65 actually has over 62. At lower angles
Here is a start: knifesteelnerds.com/2018/08/27/what-is-edge-stability/
knifesteelnerds.com/2018/09/24/edge-stability-part-2/
Not just great info, but well put in a way I can absorb. Thanks so much
I had a question I have a few knives in cromax pm, I am not sure about this knife steel and can’t find any information on it. I figured if anyone would know it would be you. Thank you so much for the amazing videos and your work in knife steel.
with the megapixel Wars it was/is worse than just optics. smart phone camera sensors they often just blow up the outputted scan; like upscaling a smaller photo in photoshop, [or hardening steels to the detriment of toughness]. So your comparison between cameras and HRC is brilliant. lol
always very very interesting to see the results of your research larrin
Another great, informative video. Thank you. Now I just need to come up with a couple designs for this bar of Magnacut in my drawer. Hmmm. 🤔
This video is amazing. It explains a lot of complex ideas (to me the noob at least) in an easy to understand way. Great usage of visuals to support the data as well. Thanks!
I love your explanation. Magnacut has been a great steel so far - tested on a lionsteel M4 with regrind. Also dig your taste in music - grim fandango ost ftw!
Great video can’t wait to get my hands on a magnacut knife!
Congrats Larrin! Absolutely amazing summary on the topic! It boils down the essentials of entire books on what's important for knife makers 🙌
Hi Larrin. Question about Magnacut heat treat warping. There seems to be a huge amount of warping with Magnacut heat treat as experienced by Gary Creely and other knife makers. Do you think there is something specific in Magnacut causing this, or perhaps heat treat companies making mistakes or just having teething problems getting used to Magnacut?
Second question, what are your thoughts about using a carbide peen hammer to straighten hardened and warped Magnacut at room temperature. Surely there would be a good chance of causing micro cracking?
Thanks for your videos. Always great info.
I wonder the same about your second question...
Have you found the answer ever since?
Amazing stuff! Would you say that 61-62 HRC MagnaCut is currently the optimal jack-of-all-trades steel for an allround knife that would be used for both survival, bushcraft and hunting?
It would work well for that
Thanks for the awesome info! Well said! 👊🏼
This video would have saved me so much misconception when I was younger. I knew most of this stuff (except for the waiting factor/austenite stabilization before cryo), but that's because I lurked Bladeforums for a decade, did cut tests, and got an mse degree. This will help so many aspiring knifemakers.
Too bad my old paragon won't get up to the 1900 to 2100 F range. I would like to try magnacut.
As someone new to this it’s extremely frustrating. It really means that the steel doesn’t matter since every manufacturer can change it so easily. Magnacut and everything can be completely different when purchased from different manufacturers
I've reached saturation. I bought Knife Engineering way before The first research smelt of CPM Magnacut. S35VN was my favorite. I hated S30V and D2 and thought my preferences were dialed in. This last Summer I got Mule Team in SPY27 and Magnacut. I am by no means a steel snob or even a complete nerd geeking on alloys because there's so much more to think about, availability to say the least. My Condor Wayfinder is great user, but I put it in a log stump point first one time and broke one or two mm of the tip without a fast sinking or hard push and zero flex while doing it.
So I can cut most of what I want and my knives hold up, but wanting to see remarkable or measurable improvement I study. But now I have two much information to decide and process. First I give up on one knife doing it all. No one steel, thermal cycle protocol or blade geometry would do over 70% of a days tasks and then there's the days of carrying the knife but not using it that day. I guess I'm thinking of the other people whose knife can do more than any of mine and I don't want to miss out on anything!
My fantasy is having a fixed blade knife and sheath system where I can cut tomato, cut a tin can to make it flat to patch a structure or cover a hole, open a six foot chain link fence, create an entry in a steel building wall and chop Barb wire line. I guess just wanting the balance that Magnacut has the most of WITH corrosion resistance is not going to answer that fantasy. Knives, nay I, myself cannot do everything I want till laser swords are affordable.
Guess I might list out what I want and prioritize them and look to make that happen.
Watching the second time helped! Lower hardness of matrix but with more Vanadium Carbides means more lasting state of sharpness.
LOVE the music!!!
So, which big name brands are making good magnacut?
Waiting to see someone in the comments do the “what makes you think you know so much about Magnacut” thing. Popcorn ready.
So, I don't make knives, at least not very often. I do make razors. Razors differ in many ways from knives but mainly in the bevel angle, and the way that the bevel angle is maintained when honing. My razors have a target bevel angle of 16° to 16.5° inclusive, i.e. the angle between one bevel face and the other. The bevel angle is not really end user selectable once the razor has been ground. Because maintaining the bevel angle precisely is more important than exactly what the angle actually is, the spine of the razor is used as a bevel guide. In honing, if the edge is on a stone, then the spine must also be on the stone, and the edge must never touch a stone unless the spine is already landed on it. This is sometimes fudged with the use of electrical or kapton tape on the spine but for the most part the bevel angle is fixed by the maker.
Razors of course are not used for chopping vegetables or butchering animals or cleaning out dovetails in cabinetry. They are for shaving and that's it. They quickly self destruct when used as knives.
My target hardness is HRC60. My HT oven is a Paragon kiln that goes up to 2000°F. This is more than enough for the carbon steels I have mostly used, and the 440C which I have tried but microscopically gave me a usable but underwhelming edge no matter what honing media was used. I had been thinking about trying S35VN but decided to go with MagnaCut instead, and I have a piece big enough for 4 razors, and I will be roughing them out some time this year.
So in light of the geometry, and the normal usage of the razor and the extreme sharpness required, I have always found that HRC 59 to 60 works well for me. I do not have a dewar or a convenient source of liquid nitrogen, and have never tried cryo. At most I will probably make one premium razor per week, from MagnaCut or similar. I am quite used to oil quenching from the austenitic state, then tempering twice for two hours at 350° to 375°F. Usually the blade is ground to shape but the edge left a minimum of 0.020" thick to reduce the number of blades that crack or warp in quench. With plate quenching of Magnacut I anticipate NOT hollowgrinding the blade until after complete heat treating, to maximize quench effectiveness. I am concerned that the small contact area of a full hollowground razor will slow down the plate quench too much. I might try one in room temperature Park 50 quench oil, but I see that nearly everyone making knives, plate quenches or air quenches this steel.
So, sorry to go on so long, but I have a question. Should I forego the cryo, for such limited production? Thinking 2000°F austenizing, plate quench, then 2x temper 2hrs at 375°F and then carefully wet grinding to keep the edge cool should give me an excellent blade with good corrosion resistance, appropriate hardness, and very good toughness. If I go 2000F and a nitro or dry ice cryo, and temper down to HRC60, I am getting close to the embrittlement range that you speak of. What are your thoughts, then, on skipping the cryo? And do you think the overall plan is sound?
Nice vid, by the way. Very informative.
Another great video mate ,thank you
Great Vid , Thanks Brother ! Juhvon sent me over !
I have many knives with different steels... by far the S90v stays the sharpest for the longest time... a few strokes on a ceramic stick puts it back to shaving hair...
Thanks for the great video and information about MagnaCut.