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Post by zebra on Oct 4, 2017 0:59:46 GMT
I know this topic has been discussed before and various forums but the answers I have seen don't make sense to me. I'd like to hear what you guys think about how sharp a katana should be.
I saw posts on another forum where some people were stating that a Katana isn't meant to feel that sharp. The rational given was that, if it felt razor sharp, the blade would not be strong enough to survive the impact with another sword. Also, because a katana does not need to be super sharp to perform basic cuts. They thought of it more like an axe to chop with than a long knife to slash with.
I'd like to believe this to be true because most of the mid to low price swords I have owned ($300 and under) have arrived feeling fairly blunt, even though they were advertised as "sharpened", "razor sharp" and "battle ready" etc. Nobody likes to believe they bought a bad product and wasted their money but.... I just can't help it with most of them.
My old martial arts teacher had a super expensive custom Katana that he had made when he was studying martial arts in Japan. He was a purist and, annoyingly, he even thought his class in Japanese even though nobody there (including him) was from Japan. His katana felt razor sharp. It wasn't movie sharp but if you ran your finger up the blade you would have more than a paper cut.
One of the moves he thought was a horizontal gut slash and I am fairly convinced (after some testing) that a sword would not cut through even thin clothing with a close range horizontal slash unless it was razor sharp.
The way it was explained to me, the blade on a Katana was not meant to clash with another sword on purpose. He thought us that the back of the sword was used to block, not the blade side. Any sword, even the best, would get a chipped and damaged blade if the blade side hit another sword with any force. Most people I know with expensive swords are fairly protective of the blade for this reason. They certainly don't test them by hitting other swords.
I wouldn't use a sword for self defense these days but if I had to choose one for this purpose, I would select one that could be made razor sharp I think.
What do do you guys think? Do your Katanas feel sharp to the touch? Do you sharpen your $200-$300 Katanas to max sharpness when they arrive?
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Post by Timo Nieminen on Oct 4, 2017 1:20:55 GMT
I am fairly convinced (after some testing) that a sword would not cut through even thin clothing with a close range horizontal slash unless it was razor sharp. People wear clothes (in many parts of the world). Swords were made to cut people (at least, many swords were designed for such). Therefore, swords need to be sharp enough to cut through clothing. Do you sharpen your $200-$300 Katanas to max sharpness when they arrive? No. But if I didn't have an adequately sharp few already, I would sharpen at least one. |
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saix1
Member
Martial Artist & Philosopher
Posts: 66
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Post by saix1 on Oct 4, 2017 1:49:21 GMT
"the blade on a Katana was not meant to clash with another sword on purpose."
What. That is literally what a parry is. And using the back side of the blade to directly block a strike is not a good idea, considering that Japanese steel was rather brittle.
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Post by stopped1 on Oct 4, 2017 2:34:19 GMT
IMHO, lots of people confuse a good keen edge with fragile hollow grind razor.
Assuming the geometry does not change, a 30 degrees edge with a good clam shell shape behind will get damaged all the same when it strikes a hard enough object, regardless of whether it is perfectly sharpened or not. A good keen edge will actually help it sail cross the target better so you will less likely bend it from scooping.
The real problem is when people change the geomtry of the blade and grind off so much meat that the angle changes (and convex becomes flat). So if you put a keen edge on without changing the angle, by all means do it. Also bear in mind, traditionally made katana breaks pretty easily compared to most of the other swords around the world. The hardened edge is considered brittle by modern standards but remains sharp for much longer, therefore it is a tool for the well trainef elite
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Post by Richard Arias on Oct 4, 2017 2:52:18 GMT
I know this topic has been discussed before and various forums but the answers I have seen don't make sense to me. I'd like to hear what you guys think about how sharp a katana should be. I saw posts on another forum where some people were stating that a Katana isn't meant to feel that sharp. The rational given was that, if it felt razor sharp, the blade would not be strong enough to survive the impact with another sword. Also, because a katana does not need to be super sharp to perform basic cuts. They thought of it more like an axe to chop with than a long knife to slash with. I'd like to believe this to be true because most of the mid to low price swords I have owned ($300 and under) have arrived feeling fairly blunt, even though they were advertised as "sharpened", "razor sharp" and "battle ready" etc. Nobody likes to believe they bought a bad product and wasted their money but.... I just can't help it with most of them. My old martial arts teacher had a super expensive custom Katana that he had made when he was studying martial arts in Japan. He was a purist and, annoyingly, he even thought his class in Japanese even though nobody there (including him) was from Japan. His katana felt razor sharp. It wasn't movie sharp but if you ran your finger up the blade you would have more than a paper cut. One of the moves he thought was a horizontal gut slash and I am fairly convinced (after some testing) that a sword would not cut through even thin clothing with a close range horizontal slash unless it was razor sharp. The way it was explained to me, the blade on a Katana was not meant to clash with another sword on purpose. He thought us that the back of the sword was used to block, not the blade side. Any sword, even the best, would get a chipped and damaged blade if the blade side hit another sword with any force. Most people I know with expensive swords are fairly protective of the blade for this reason. They certainly don't test them by hitting other swords. I wouldn't use a sword for self defense these days but if I had to choose one for this purpose, I would select one that could be made razor sharp I think. What do do you guys think? Do your Katanas feel sharp to the touch? Do you sharpen your $200-$300 Katanas to max sharpness when they arrive? Modern steel and skills allow sharp thin blades to take abuse. I took a Hanwei Unokubi Zukiri Raptor and put $500 into it. Getting it sharpened to 1/4 micron, New handle, new Mekugi ex. In my mind it's always best to buy a blade you like that fits you and fix the areas where they fall short. With the Raptor it's crap handles and Blade finish. Literally had a student cut 12to6 into a 4x4 cutting post and the edge has no damage. Can't say the same for a lot of blades, many more expensive. Modern combat situations I have a Raptor Waki that I customized with an 8in tsuka and a resharpen. With a total length of 26in its good weight in a combat situation. It does not have to be a lesser edge because no armor will be encountered. So I can have a super sharp edge that is effective against medium and hard targets while the keen edge lasts. And with half price sharpening it's no big issue. But even as an edge gets dull the blade still thrusts and the geometry will still cut. The higher sharpness levels just make up for when your technical ability is off. It's a choice you have to make depending on your intent of use. |
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Post by treeslicer on Oct 4, 2017 4:35:23 GMT
A few points: - Katana are fragile by Western standards, and are designed to slice, not chop. The real thing (nihonto) has an edge hardened to the low 70's HRC, and containing carbon nanotubes and other bizarre microstructures from the forging and quenching processes. It will hold an edge like nothing else (except for some rare and expensive modern superalloy swords that you're probably never going to buy), but chips easily. and, being a very stiff sword, has a tendency to break or bend disastrously when overstressed.
- Yes, you have to be well trained and thoroughly practiced to use them effectively.
- Chinese production swords are usually not capable of holding a nihonto-like edge (however, there ARE exceptions, and price is not a good predictor in finding them), but all should be able to hold a "razor" edge sufficient to slash common targets cleanly, shave hair, skin animals, etc. Any that won't are defective. Most are somewhere in the HRC 60's at the edge, and much less likely to chip than nihonto.
- A good test of sharpness is to drag a blade's monouchi edge backwards while resting it on a horizontal piece of pool noodle. If the blade digs in under its own weight, and slices into the foam cleanly and deeply, it's sharp enough.
- All Chinese swords I have bought required much more sharpening than they got at the factory before I could do tameshigiri with them.
- Your sensei was mostly correct. The mune (much softer and less quenched than the edge) is used to block cuts and chip other swords, also to beat people with in non-lethal situations. What he didn't tell you is that the shinogi is used to deflect cuts. One of my katateuchi dating to the Sengoku clearly shows clash damage from doing this repeatedly. I think someone was using it left handed and fighting some style similar to Florentine (Maybe Musashi once scratched his posterior with it, who knows?).
- Due to their geometry, unokubi-zukuri blades are harder to sharpen than shinogi-zukuri blades, and seem to arrive duller than the others.
- In closing, yes, get your blades razor sharp, but don't foul up the designed blade geometry doing it.
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Post by MOK on Oct 4, 2017 7:29:37 GMT
There are several very different things being conflated under "sharpness", here. One is the honing and polish of the very edge. This keeps the edge smooth, straight and sharply defined, which is what makes it feel sharp to the touch and facilitates parting the target to be cut instead of crushing it. Conventionally Japanese swords are polished very fine and smooth, at least in modern times, but this isn't the case with all sword types and traditions: some Victorian sources, for example, recommend sharpening a saber with just a file and leaving the finish somewhat toothy, to help it bite (and there is something to that). On the other hand, another measure of "sharpness" is the angle at which the edge bevels meet. A very acute angle makes the edge more, well, acute, and also eliminates friction between the blade and the target. On the other hand, it also makes the edge thin and thus prone to deforming and/or breaking. So, for optimal performance a functional compromise is needed between ease of cutting and structural integrity - extreme sharpness is of little use if the blade breaks on the first swing. Then there's also the hardness of the steel: harder steel can be formed more precisely (so it can take a sharper edge in one sense of the word) and is more resistant to deformation, so stays sharp longer with less maintenance, but is also more prone to breaking, and maintaining it is harder work when (not if!) called for - and major breaks might not be able to be fixed at all. So again a compromise is needed. I have a seax that's "razor sharp" in the sense that the edge is smooth and sharply defined enough to shave hair. Same with a couple of axes. Also a modern camp chopper, but it's more roughly finished, like those Victorian sabers, and would scratch and slice your skin if you tried (and bites into stuff scary well). However, their blades are thick and the edge angles quite obtuse, compared to actual razor blades, so there's considerably more friction during the cut - actually shaving with them would be quite unpleasant; yes, I've tried  - but they'll withstand all sorts of stress inherent in using a large blade in combat (or survival chores) that would snap a razor in two instantly. I use spent razor blades for cutting leather, and being extremely thin and still very sharp (though not sharp enough to shave comfortably with) they excel at it; but if I were to swing one of them at a sword cutting target, the most I could reasonably expect would be some superficial scratches and likely a broken razor blade.  Most swords fall somewhere in between, depending on their exact type and intended use; historical katana, tachi etc. are no different from and no more uniform than other swords, and also vary in their amount of "meat" (i.e. edge angle and the convexity of the bevels) and level of edge polish. |
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Post by Timo Nieminen on Oct 4, 2017 8:09:53 GMT
Katana are fragile by Western standards, and are designed to slice, not chop. The real thing (nihonto) has an edge hardened to the low 70's HRC, and containing carbon nanotubes and other bizarre microstructures from the forging and quenching processes. Usually low 60s HRC or lower. E.g., the sword studied in Yaso et al. www.esomat.org/articles/esomat/abs/2009/01/esomat2009_07018/esomat2009_07018.html reaches about 60HRC at the edge; they cite other studies which report somewhat higher hardnesses (low 60s HRC). The same authors later (Journal of Alloys and Compounds 577S (2013) S690-S694) measured another sword (Muromachi) which reached the mid-60s at the edge (880HV) - this is the hardest old nihonto I've seen reported. Supposedly, plenty of koto swords are significantly softer than this. Haven't seen any first-hand reports of measurements; some discussion at www.militaria.co.za/nmb/topic/14014-how-hard-is-the-edge/I'd be surprised by significant amounts of stuff like carbon nanotubes - the steel is usually about 0.7% carbon (pretty much equivalent to 1070, albeit with more slag inclusions). Where nanotubes turn up in quantity is wootz blades, but wootz blades can be over 1.5% carbon (and the nanotubes don't do anything amazing for the blade (unlike small cementite grains, which do contribute a lot to the properties, notably wear resistance and edge retention), but better nanotubes (and fullerenes/buckyballs) which are mostly harmless than graphite sheets which would weaken the blade a lot). Chinese production swords are usually not capable of holding a nihonto-like edge (however, there ARE exceptions, and price is not a good predictor in finding them), but all should be able to hold a "razor" edge sufficient to slash common targets cleanly, shave hair, skin animals, etc. Any that won't are defective. Most are somewhere in the HRC 60's at the edge, and much less likely to chip than nihonto. 60HRC is often claimed, but the actual swords might fall short of that quite often: sbg-sword-forum.forums.net/thread/39740 |
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Post by aphetchakan on Oct 4, 2017 8:22:45 GMT
I have bought the Katana from eBay under sub $200. It was advertised very sharp but it was actually not really sharp. However their blade is still good, well balance and it’s easily to be sharpen more. I am able to sharpen the blade to be razor sharp by sand paper and leather.
I buy the sword for NOT fighting, I buy it for the backyard cutting and I would not cut the big tree or iron (Hard thing). I want something super sharp to cut to soft target such a fresh bamboo, empty bottle (no water filled), paper roll, empty cola can. It will not be fun for me if the sword is not extremely sharp, I don’t want something like an axe to cut the big tree.
Some people like something very sharp, some people like not too sharp to cut hard target. It is depending on what you wanted.
Remark: I have another katana at sub $450 from eBay also. The blade is extremely smooth and sharp.
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Post by treeslicer on Oct 4, 2017 14:22:37 GMT
Katana are fragile by Western standards, and are designed to slice, not chop. The real thing (nihonto) has an edge hardened to the low 70's HRC, and containing carbon nanotubes and other bizarre microstructures from the forging and quenching processes. Usually low 60s HRC or lower. E.g., the sword studied in Yaso et al. www.esomat.org/articles/esomat/abs/2009/01/esomat2009_07018/esomat2009_07018.html reaches about 60HRC at the edge; they cite other studies which report somewhat higher hardnesses (low 60s HRC). The same authors later (Journal of Alloys and Compounds 577S (2013) S690-S694) measured another sword (Muromachi) which reached the mid-60s at the edge (880HV) - this is the hardest old nihonto I've seen reported. Supposedly, plenty of koto swords are significantly softer than this. Haven't seen any first-hand reports of measurements; some discussion at www.militaria.co.za/nmb/topic/14014-how-hard-is-the-edge/I'd be surprised by significant amounts of stuff like carbon nanotubes - the steel is usually about 0.7% carbon (pretty much equivalent to 1070, albeit with more slag inclusions). Where nanotubes turn up in quantity is wootz blades, but wootz blades can be over 1.5% carbon (and the nanotubes don't do anything amazing for the blade (unlike small cementite grains, which do contribute a lot to the properties, notably wear resistance and edge retention), but better nanotubes (and fullerenes/buckyballs) which are mostly harmless than graphite sheets which would weaken the blade a lot). Chinese production swords are usually not capable of holding a nihonto-like edge (however, there ARE exceptions, and price is not a good predictor in finding them), but all should be able to hold a "razor" edge sufficient to slash common targets cleanly, shave hair, skin animals, etc. Any that won't are defective. Most are somewhere in the HRC 60's at the edge, and much less likely to chip than nihonto. 60HRC is often claimed, but the actual swords might fall short of that quite often: sbg-sword-forum.forums.net/thread/39740My Japanese numbers come from 1930's gunto development research made available on the internet, and were reported from a certain "cherry-picked" sample of koto blades selected as comparison benchmarks. I'll freely grant that they represent an extreme. I base my assertion of low '60's for mediocre DH Chinese production blades on file testing. I consider the entire subject controversial due to differences in methodologies between published studies, as well as possible experimenter bias, and the inhomogeneous nature of what's being investigated (each traditionally made sword is different from every other). I also consider this forum to be a less than optimal venue for debating the subject. I do, however, find that the general tendency is for a majority of nihonto to cut more freely than a majority of Chinese examples, and to hold sharper edges longer in use, whatever that might mean metallurgically. I also consider that some of the observed differences between Chinese swords are due to a lack of consistency in removing the decarburized surface layer when finishing the swords. I've found that, in most cases, the more I polish, the harder they seem to get. As far as published Chinese hardness claims go, eBay sellers often contradict themselves in their ad copy on matters of steels used. number of folds executed, etc. I'd be surprised if they have any clue whatsoever as to how hard their edges get.  I have found that, in practice, Lonqquan DH swords are adequate for tameshigiri when properly sharpened. |
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Post by Timo Nieminen on Oct 4, 2017 15:55:22 GMT
If you mean the hardness values as measured by Tawara, as given on e.g. ohmura-study.net/998.html , those don't appear to be HRC. I've not read Tawara's original publication (and I don't know of any English translation), and I don't know what hardness scale he used, but almost certainly not HRC. Tawara died in 1918, before Rockwell's hardness testing patent was granted, and before commercial production of Rockwell testing equipment. |
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Post by treeslicer on Oct 4, 2017 18:03:51 GMT
If you mean the hardness values as measured by Tawara, as given on e.g. ohmura-study.net/998.html , those don't appear to be HRC. I've not read Tawara's original publication (and I don't know of any English translation), and I don't know what hardness scale he used, but almost certainly not HRC. Tawara died in 1918, before Rockwell's hardness testing patent was granted, and before commercial production of Rockwell testing equipment. Yeah, that's one of my references, but the Tawara data is incorporated in a 1930's tech report, which adds the contemporarily measured Koa-Issin numbers, and then edited for the website. Some conversions may have been done. All the columns besides the maximum would be noncontroversial values as HRC. I'll have to contact them, and try to find out what scale was used. God have mercy on my shaky Japanese. Thanks. |
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Post by Timo Nieminen on Oct 5, 2017 4:47:50 GMT
Looking at the common hardness tests back when Tawara worked (Brinell ball, Shore scleroscope), the values look like Shore scleroscope hardnesses. On the Shore scale, 81 = 60HRC, 72 = 55HRC. Shore-HRC conversion table: mdmetric.com/tech/hardnessconversion.html |
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Post by seriouslee on Oct 9, 2017 4:01:35 GMT
My sense of the sword is to cut and stab not blade to blade contact, under any circumstances.
The sharper the better - were I expecting combat. Since I am not, I leave them as they come out of the box.
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Post by zabazagobo on Oct 9, 2017 17:20:24 GMT
My 0.02 is that you do want a keen edge with a geometry that's optimized for what it'll be going up against (more niku for heavier armor, etc.). Blade to blade contact is common, parrying is one of the most important skills to practice, although you'd want to use the flats of the blade as well, if you make contact near the shinogi you won't chip the blade and the slope aids deflection. I also argue that at some point you definitely don't want to make an edge as sharp as possible. They chip more easily. So after a point there's diminishing returns with hard steel and sharper edges.
Traditionally, a general HRC for a katana edge would be high 50's or low 60's, like Timo mentioned. As soon as steel that hard has an edge that is profiled correctly, it will cut like a laser, and with a softer spine it will take abuse. But only given the geometry is conducive towards the cut. Richard Arias' points about how nowadays with spring steel hira zukuri can become an extremely viable blade are on the mark, as the overall geometry has a significant effect on performance.
Personally, for me 'razor sharp' is kind of overrated since it'll chip. A robust edge (i.e. healthy niku) that'll survive hard impacts and a blade that won't bend or snap easily is better in my opinion for a combat scenario. For pure cutting, a razor edge with a smooth geometry is the best (like the hira zukuri Richard mentioned). Just depends on intended use.
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Post by Timo Nieminen on Oct 9, 2017 21:22:57 GMT
Personally, for me 'razor sharp' is kind of overrated since it'll chip. A robust edge (i.e. healthy niku) that'll survive hard impacts and a blade that won't bend or snap easily is better in my opinion for a combat scenario. For pure cutting, a razor edge with a smooth geometry is the best (like the hira zukuri Richard mentioned). Just depends on intended use. Robust geometry with lots of niku doesn't have anything to do with the sharpness of the edge, though. Sure, it affects cutting, but "sharpness" is about the very edge. So, a question: take a robust blade with lots of niku. Sharpen it with a 100 grit stone. It will cut, and there will be a certain chance of chipping the edge if you hit something hard (a low chance, one would expect). Take that same blade, and sharpen it progressively to 400 grit, 2000 grit, and 10,000 grit. Keeping the same edge angle of course, taking off as little steel as possible. How much more likely is the 10,000 grit version of the blade to chip than the 100 grit version? The 10,000 grit version will be better at cutting through clothing. |
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Post by treeslicer on Oct 9, 2017 23:40:22 GMT
<abbr>Accidental double post. I deleted it.
</abbr>
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Post by treeslicer on Oct 9, 2017 23:44:55 GMT
Robust geometry with lots of niku doesn't have anything to do with the sharpness of the edge, though. Sure, it affects cutting, but "sharpness" is about the very edge. So, a question: take a robust blade with lots of niku. Sharpen it with a 100 grit stone. It will cut, and there will be a certain chance of chipping the edge if you hit something hard (a low chance, one would expect). Take that same blade, and sharpen it progressively to 400 grit, 2000 grit, and 10,000 grit. Keeping the same edge angle of course, taking off as little steel as possible. How much more likely is the 10,000 grit version of the blade to chip than the 100 grit version? The 10,000 grit version will be better at cutting through clothing. Couldn't we be into something of a causal fallacy here on the relationship of edge fineness (not to be confused with "thinness", which does increase chipping) to chipping tendency, because it requires a harder steel to hold a finer edge, and the harder a carbon steel is, the more likely it is to chip? I couldn't agree more on using the 10,000 grit (or finer) stones. The finer the edge, the better it cuts. Period. That's as true for swords as it is for woodcarving tools, and regardless of the apex angle. Even a sharper cold chisel cuts copper better than a dull one, and that's a 60 degree angle. |
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Post by zabazagobo on Oct 10, 2017 1:48:52 GMT
Personally, for me 'razor sharp' is kind of overrated since it'll chip. A robust edge (i.e. healthy niku) that'll survive hard impacts and a blade that won't bend or snap easily is better in my opinion for a combat scenario. For pure cutting, a razor edge with a smooth geometry is the best (like the hira zukuri Richard mentioned). Just depends on intended use. Robust geometry with lots of niku doesn't have anything to do with the sharpness of the edge, though. Sure, it affects cutting, but "sharpness" is about the very edge. So, a question: take a robust blade with lots of niku. Sharpen it with a 100 grit stone. It will cut, and there will be a certain chance of chipping the edge if you hit something hard (a low chance, one would expect). Take that same blade, and sharpen it progressively to 400 grit, 2000 grit, and 10,000 grit. Keeping the same edge angle of course, taking off as little steel as possible. How much more likely is the 10,000 grit version of the blade to chip than the 100 grit version? The 10,000 grit version will be better at cutting through clothing. Right, I didn't mean to imply that niku relates to sharpness (my curious case with a blade with more niku chipping on targets whereas a blade with less niku didn't is a testament to that), I sort of got off into a tangent about other factors contributing to performance as a razor sharp edge has its flaws and how just having the sharpest weapon may not be the most effective weapon if it becomes damaged too easily. So I was just playing devil's advocate that sharpness is desirable but you don't necessarily want something to be too fine and sharp. I agree completely about sharpness and niku being independent. An example I experienced of niku not having anything to do with sharpness is when I compare two of my blades, one is a Hanwei Bushido with decent niku, and another is a Huawei t10 (kanmuri-otoshi) with less niku and both are appreciably sharp though the Bushido seems finer. Of the two, doing similar kinds of hard target cutting (i.e. tree branches), only the Hanwei suffered any chipping but it also sailed through the targets appreciably easier. So, I'm not sure why the blade with more niku would have chipped if not for being too zealously sharpened, which when I inspect it even now I'd argue seems to be the case. Do you think that all adds up, or might there be something else at work? |
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Post by Timo Nieminen on Oct 10, 2017 4:51:32 GMT
Couldn't we be into something of a causal fallacy here on the relationship of edge fineness (not to be confused with "thinness", which does increase chipping) to chipping tendency, because it requires a harder steel to hold a finer edge, and the harder a carbon steel is, the more likely it is to chip? I think you're more likely to get microscopic chips if the edge is finer, and if the steel is softer, you're more likely to like microscopic rolling of the edge. For hard-edged (60+ HRC) kitchen knives that I've looked at the edge under magnification over time as they blunten, it's all been micro-chipping, but all very tiny. So, in a sense, chipping is much more likely, but this is mostly chipping at a level that's just bluntening of the edge in use. There is, I guess, a chance that you might get unlucky, and a microscopic crack can grow into a big one, and give you a big chip. But I don't think this is likely to happen - the chance of chipping (with large chips) might be higher, but only a little bit higher. My son hit a steel cutting stand base with a hard-edged sword (sanmei liuyedao), and chipped part of the edge (very shallow, but a few mm long). I think if the edge had been blunt, it might have survived with no chipping. But the chipping was very shallow, and basically just bluntened the edge to the level at which it wouldn't have chipped. So, in a functional sense, starting sharper caused no real harm. (But keeping the blade really sharp all the time means that it will need to be sharpened more often, which will reduce the life of the blade due to frequent sharpening removing more steel.) I agree completely about sharpness and niku being independent. An example I experienced of niku not having anything to do with sharpness is when I compare two of my blades, one is a Hanwei Bushido with decent niku, and another is a Huawei t10 (kanmuri-otoshi) with less niku and both are appreciably sharp though the Bushido seems finer. Of the two, doing similar kinds of hard target cutting (i.e. tree branches), only the Hanwei suffered any chipping but it also sailed through the targets appreciably easier. So, I'm not sure why the blade with more niku would have chipped if not for being too zealously sharpened, which when I inspect it even now I'd argue seems to be the case. Do you think that all adds up, or might there be something else at work? Different steel, different heat treatment -> different behaviour. But, as above, sharper will mean more chance of microscopic chips, and maybe more (but not much more) chance of larger chips. How big were the chips? More niku should at least reduce the depth of chips, so will provide protection even if it doesn't eliminate chipping completely. |
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- but they'll withstand all sorts of stress inherent in using a large blade in combat (or survival chores) that would snap a razor in two instantly.
I have found that, in practice, Lonqquan DH swords are adequate for tameshigiri when properly sharpened. 
