Very good insight into the difference between toughness and strength. With all the internet excitement about Magnacut, one commonly held view I have read is that its toughness will allow for more acute edge angles. This video demonstrates that the toughness is there, but the limit of maximum hardness will also effect the stability of thin edges in hard use.
If I'm not mistaken this knife is Re HT from 63.5 RC at HT 5 TF5.25 | 0.5. Its toughness at 64RC is excellent. In my personal opinion, I can sacrifice a bit of strength for more toughness. Because when using small and medium-sized knives to work with wood, pushing and twisting the blade is used quite often, then the toughness of the edge is very important. Thank for sharing.
Yup, it was re-sequenced from HT 5 TF5.25|0,50. At 64rc now, it has awesome edge stability & good wear resistance as well. I will check to see if this was the one you asked me about earlier...
Thanks for the time you put into your testing. As a knife maker the testing you perform show me how a steel will perform being subjected to real world uses. I'm my opinion this is the sort of testing that you need to be conducted to base its performance on. I think I'll be sticking with Nitro-V & Aeb-l. This new Steel being touted as being so much more superior that others on the market is by someone who I believe has gone out of their way to do articles on other steels in its category that it would be competing against & has reviewed them & there potential negatively based on his own test results from the way he states the steel must be HT.
I haven yet test magnacut wear & corrosion resistances. Based on this impact usability/edge-stability test, 64rc magnacut exhibited excellent toughness but insufficient strength. If able(not sure my current sequencing can achieve this hrd) to compare 64rc aebl/nitro-v, high likeliness these 2 steels would be tougher but slightly less strength (dur to lower carbide volume) than magnacut. All 3 at 64rc, most likely magnacut has better wear resistance. Corrosion to-be-seen/test.
Magnacut will for sure have better edge retention at the same hardness of aebl and those related steels. Magnacut has more lateral strength as well. I’ve heard 62.5 or so is a good number for magnacut if you’re going for high toughness and avoiding chips/microchipping.
Mr la. So why such strength difference between magnacut and 4v type steel? Is it just the hrc difference 64.5 and 66? Is it the steel chemistry the ht protocol is the same correct? So why such a gap in performance?
Peak hrc of Vanadis4E/4V is around 67+rc, where MC is 65.5rc. Hrc is a measure of resistance to displacement (spread out), so it is only a partial measurement of strength. 64 vs 66 is not a linear delta 2, realistically sort of logarithmic, thus delta strength reflected in result seen. Both steels sequence & finished together (same everything except austenite temperature). If I keep same sequences but change some params, push MC to 65+rc, then perform same test. It would result close/similar to current V4E. I don't interpret 64rc MC's result as poorer than 66rc V4E, rather it just not strong enough. Recalling earlier tests, same hrc - Niolox vs magnacut, niolox edge deformed a lot more. My interpretation was = niolox is tougher but less strength. So between 66rc V4E & 64rc MC *as tested* which one I would pick for test tasks oriented performance. 66rc V4E every 8 days of the week :)
There is one thing I seen in the few knifes I made. Mostly in AEB-L and Nitro-V. Made more then a few knifes in those two steels. But I would say Nitro-V is not a good steel. Maybe I heat treated them wrong or who knows, but I used pretty much same treat as in AEB-L and high heat and regular heat. For some reason? Nitro-V cant keep an edge worth shit, its like playdough. Even knifes I made in the same batch of AEB-L and nitro V. AEB-l is superior to nitro V hands down. And? Another thing, not to sure how much this effects things since I didnt do that many steels. But Nitrogen, AEB-L and Nitro-V pretty much same steel. Only difference is the nitrogen content. When I broke knifes in two? You can see with your eyes the big ol chromium carbide in the nitro-V steel easily. In AEB-L? Nothing. The grain blows up fast in Nitro-V. And it has the same effect? The edge rolls like its butter, especially when thin. And since its stainless, one you get a glint at the edge? It will only just grow with use and litterally juct a giant chip in that area in time. This steel? Magnacut? Cant comment on it. Definitely better then the two steels I was talking about. But? They should try to make a version of this steel without the nitrogen added in there. Its my own particular fascination. But I think adding nitrogen the way they do it, especially in lower end steels like Nitro-V? Does something to the composition which makes it shit. I have a knife in Vanax. And as you know its loaded with nitrogen. Never had the problem with Vanax. So it could be something else, but I never really tested Vanax out all that hard. The dam steel is to expensive to treat it like I did the Nitro-V and AEB-L knifes. But for me? If its tougher then and more stain resistant then elmax? Im sold on Magnacut? But I also that if they change a few things up in the composition? It could be a much better steel. But then again? Anything so saturated with free chromium? May up the stain resistance. But seems to make the edge roll easier when the steel has lots of free chromium in the system. At the end of the day? A carbon steel will beat a stainless steel in the edge toughness test. Its just how it goes. Your trading something, to get something, and vice versa. 4V and vandius 4extra? Does rust.
I think you should seek out people who are experts in the field of thermal dynamics & not what is written on forums. You can't HT Nitro-V the same as AEB-L it had a different composition than AEB-L its no wonder your AEB-L performance was good and Nitro-V was terrible. It's because you used AEB-L HT protocol. If you want to see the full potential of Nitro-V performance it needs to be Vacuum hardened gas quench or deep Cryo. I've tried a heap of different steels and Nitro-V is my top choice followed by AEB-L. Overall Nitro-V has the best performance from actual working with it, its consistency from each batch & it's ease of maintainability of its edge by the end user. Ive used NitroV to make around 450 knives from small to large all with a specialist & costly deep Cryogenic heat treatment and its exceeded my expectations & that of my customers who use the knives regularly.
N(itrogen) in solution has higher potential energy than C(arbon), hence martensite transformation at lower temperature. I suspect your ht protocol resulted in higher RA%, which would explain mushiness edge and sudden chip. See additional thoughts in my reply to Kraken Tactical's comment...
For steels with nitrogen: Instead of vacuum gas quench, ideally should use high pressure nitrogen ht chamber to prevent nitrogen escape and create gradient from surface to interior of blade. Agreed, LN2 should be use to convert RA to Martensite. Also nitrogen is sensitive to CCT rate than carbon, where high plate martensite% lead to higher RA%. Plate martensite is brittle compare to lath.
Luong thats what I meant when referring to gas quench using high pressure nitrogen gas within chamber to increase heat transfer coefficient. Have also tried Helium quench in the beginning when testing however cost was very high & for some reason it became difficult to establish a cutting edge I was happy with similar to D2. Best results are nitrogen gas quench to room temperature followed by deep Cryo in liquid nitrogen.
Super! Using such protocol, your blades should (expected) achieved top-tier in performance. Thanks for clarifying, good to be on a same page (in realm of conventional ht).
Very good insight into the difference between toughness and strength. With all the internet excitement about Magnacut, one commonly held view I have read is that its toughness will allow for more acute edge angles. This video demonstrates that the toughness is there, but the limit of maximum hardness will also effect the stability of thin edges in hard use.
Well said!
As always very informative!
If I'm not mistaken this knife is Re HT from 63.5 RC at HT 5 TF5.25 | 0.5.
Its toughness at 64RC is excellent.
In my personal opinion, I can sacrifice a bit of strength for more toughness. Because when using small and medium-sized knives to work with wood, pushing and twisting the blade is used quite often, then the toughness of the edge is very important.
Thank for sharing.
Yup, it was re-sequenced from HT 5 TF5.25|0,50. At 64rc now, it has awesome edge stability & good wear resistance as well. I will check to see if this was the one you asked me about earlier...
Thanks for the time you put into your testing. As a knife maker the testing you perform show me how a steel will perform being subjected to real world uses. I'm my opinion this is the sort of testing that you need to be conducted to base its performance on.
I think I'll be sticking with Nitro-V & Aeb-l. This new Steel being touted as being so much more superior that others on the market is by someone who I believe has gone out of their way to do articles on other steels in its category that it would be competing against & has reviewed them & there potential negatively based on his own test results from the way he states the steel must be HT.
I haven yet test magnacut wear & corrosion resistances. Based on this impact usability/edge-stability test, 64rc magnacut exhibited excellent toughness but insufficient strength. If able(not sure my current sequencing can achieve this hrd) to compare 64rc aebl/nitro-v, high likeliness these 2 steels would be tougher but slightly less strength (dur to lower carbide volume) than magnacut. All 3 at 64rc, most likely magnacut has better wear resistance. Corrosion to-be-seen/test.
Magnacut will for sure have better edge retention at the same hardness of aebl and those related steels. Magnacut has more lateral strength as well. I’ve heard 62.5 or so is a good number for magnacut if you’re going for high toughness and avoiding chips/microchipping.
BRUTAL TEST… WELL DONE! THANK YOU… GREAT TOUGHNESS, BUT SOME PLASTIC DEFORMATION !… GREAT KNIFE STEEL, BUT NOT AXE MATERIAL (@ 15 Degrees/Side)
Mr la. So why such strength difference between magnacut and 4v type steel? Is it just the hrc difference 64.5 and 66? Is it the steel chemistry the ht protocol is the same correct? So why such a gap in performance?
Peak hrc of Vanadis4E/4V is around 67+rc, where MC is 65.5rc. Hrc is a measure of resistance to displacement (spread out), so it is only a partial measurement of strength. 64 vs 66 is not a linear delta 2, realistically sort of logarithmic, thus delta strength reflected in result seen. Both steels sequence & finished together (same everything except austenite temperature).
If I keep same sequences but change some params, push MC to 65+rc, then perform same test. It would result close/similar to current V4E. I don't interpret 64rc MC's result as poorer than 66rc V4E, rather it just not strong enough. Recalling earlier tests, same hrc - Niolox vs magnacut, niolox edge deformed a lot more. My interpretation was = niolox is tougher but less strength.
So between 66rc V4E & 64rc MC *as tested* which one I would pick for test tasks oriented performance. 66rc V4E every 8 days of the week :)
@@BluntCutMetalWorks 🙏 thank you Mr.la. I needed this explanation
eucalyptus smells nice when you chop it.
There is one thing I seen in the few knifes I made. Mostly in AEB-L and Nitro-V. Made more then a few knifes in those two steels. But I would say Nitro-V is not a good steel. Maybe I heat treated them wrong or who knows, but I used pretty much same treat as in AEB-L and high heat and regular heat. For some reason? Nitro-V cant keep an edge worth shit, its like playdough. Even knifes I made in the same batch of AEB-L and nitro V. AEB-l is superior to nitro V hands down.
And? Another thing, not to sure how much this effects things since I didnt do that many steels. But Nitrogen, AEB-L and Nitro-V pretty much same steel. Only difference is the nitrogen content. When I broke knifes in two? You can see with your eyes the big ol chromium carbide in the nitro-V steel easily. In AEB-L? Nothing. The grain blows up fast in Nitro-V. And it has the same effect? The edge rolls like its butter, especially when thin.
And since its stainless, one you get a glint at the edge? It will only just grow with use and litterally juct a giant chip in that area in time. This steel? Magnacut? Cant comment on it. Definitely better then the two steels I was talking about. But? They should try to make a version of this steel without the nitrogen added in there. Its my own particular fascination. But I think adding nitrogen the way they do it, especially in lower end steels like Nitro-V?
Does something to the composition which makes it shit. I have a knife in Vanax. And as you know its loaded with nitrogen. Never had the problem with Vanax. So it could be something else, but I never really tested Vanax out all that hard. The dam steel is to expensive to treat it like I did the Nitro-V and AEB-L knifes. But for me? If its tougher then and more stain resistant then elmax? Im sold on Magnacut? But I also that if they change a few things up in the composition? It could be a much better steel.
But then again? Anything so saturated with free chromium? May up the stain resistance. But seems to make the edge roll easier when the steel has lots of free chromium in the system. At the end of the day? A carbon steel will beat a stainless steel in the edge toughness test. Its just how it goes. Your trading something, to get something, and vice versa. 4V and vandius 4extra? Does rust.
I think you should seek out people who are experts in the field of thermal dynamics & not what is written on forums. You can't HT Nitro-V the same as AEB-L it had a different composition than AEB-L its no wonder your AEB-L performance was good and Nitro-V was terrible. It's because you used AEB-L HT protocol.
If you want to see the full potential of Nitro-V performance it needs to be Vacuum hardened gas quench or deep Cryo. I've tried a heap of different steels and Nitro-V is my top choice followed by AEB-L. Overall Nitro-V has the best performance from actual working with it, its consistency from each batch & it's ease of maintainability of its edge by the end user.
Ive used NitroV to make around 450 knives from small to large all with a specialist & costly deep Cryogenic heat treatment and its exceeded my expectations & that of my customers who use the knives regularly.
N(itrogen) in solution has higher potential energy than C(arbon), hence martensite transformation at lower temperature. I suspect your ht protocol resulted in higher RA%, which would explain mushiness edge and sudden chip. See additional thoughts in my reply to Kraken Tactical's comment...
For steels with nitrogen: Instead of vacuum gas quench, ideally should use high pressure nitrogen ht chamber to prevent nitrogen escape and create gradient from surface to interior of blade. Agreed, LN2 should be use to convert RA to Martensite. Also nitrogen is sensitive to CCT rate than carbon, where high plate martensite% lead to higher RA%. Plate martensite is brittle compare to lath.
Luong thats what I meant when referring to gas quench using high pressure nitrogen gas within chamber to increase heat transfer coefficient. Have also tried Helium quench in the beginning when testing however cost was very high & for some reason it became difficult to establish a cutting edge I was happy with similar to D2. Best results are nitrogen gas quench to room temperature followed by deep Cryo in liquid nitrogen.
Super! Using such protocol, your blades should (expected) achieved top-tier in performance. Thanks for clarifying, good to be on a same page (in realm of conventional ht).