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Post by Robert in California on Oct 20, 2014 15:50:34 GMT
www.ryujinswords.com/koaisshin.htmohmura-study.net/998.html(Thanks LGM!) Think one of the China forges would make a blade thus? Huawei? Someone? If they did, who would buy if for say...$400usa for a katana or $300 for a waki? RinC ========================================================================== 22Oct14 update on "Who could make KoaIsshin "low carbon steel rod inside a high carbon steel pipe" blade: 1. Wang-katana2011 (Longquan): mono, folded and kobuse, yes. KoaIsshin, no. 2. Huawei (Longquan): Jacky says he is willing to try to make the blade. But does not have the WWII gunto furniture (which is fine to me as gunto furniture swords are awkward to use). 3. Katana1980 (Longquan): no yes or no answer yet.
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Mikeeman
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Post by Mikeeman on Oct 20, 2014 17:52:00 GMT
That's pretty neat. A very simplistic approach to a very complicated problem.
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Post by LG Martial Arts on Oct 20, 2014 18:20:23 GMT
That's a nice sword, even if it wasn't consteucted in a "conventional" manner. Wouldn't mind having one in my collection.
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Post by Jeffrey Ching on Oct 20, 2014 18:38:18 GMT
This indeed sounds like an great way to combine tradition with science. I never heard of anyone actually doing this pipe welding on a Japanese style sword but if it works, it could make one hell of a cutter Anyway, I also haven't heard of a sword smith reaching 72HRC with 1060(ish) steel... That's damn impressive. Most likely these blades would have a fair amount of niku to withstand the stress of the yaki-ire as well as to prevent easy chipping. First person that comes to mind is the late Bob Engnath, he would definitely be into this. The second candidate would be Jesus Hernandez, the stuff this guy does with cables, rods and homebrew oroshigane... sooo, who's volunteering?
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Post by Robert in California on Oct 20, 2014 19:08:37 GMT
I emailed the Jacky of Huawei and Tony of Katana1980 the link and asked them what they thought. They both having swordsmiths. Asking them if they thought that method of blade construction would have interest to them. I'll report back the gist of their replies. While my wife told me I need no more swords (and she is correct...I "need" no more, "need" being different from "want"), I still would be tempted if someone there in Longquan did a good job of making a blade with that technique of a low carbon steel rod inside a high carbon steel pipe which is then forged into blade shape (via power hammer like most affordable Longquan sword blades).
Currently we have mono steel...a flat bar of varying grade and type steel forged into a blade...which works well enough. And folded steel where two types of steel slabs are forged together with folding.
Would not a "rod in pipe" type blade be easier and with a lower failure rate than making folded blades?
One sword seller over there told me that his failure rate with folded blades is noticeably higher than with mono steel blades. Not the first time I have heard that.
I would think a "rod in pipe" blade would uses a mono rod in a mono pipe.
Then from there, the standard forging and clay-tempering would be about the same process as the other blade types.
BTW, mono steel swords do not seem to be idiot proof. Longquan sword seller Wang-katana2011's sword factory/forge tried but failed and finally gave up trying to make me a wide-hamon mono 1095 katana blade....too much blade bending in the water quench. But for some reason, they had better luck with a wide hamon on a folded or a kobuse blade.
RinC
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Post by LastGodslayer on Oct 20, 2014 20:10:15 GMT
I am skeptical of the 72HRC value... No where near enough carbon in the kawagane to go above 60-ish. 72 HRC can't even be acheived with plain carbon steel. To get that high up you need a lot of big mean hard carbides in there...
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Post by Onimusha on Oct 20, 2014 20:27:21 GMT
At the last blade show I attended, James Williams said something about this method. I think Bugei had a blade made that way at the time.
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Post by Robert in California on Oct 20, 2014 21:36:59 GMT
"I am skeptical of the 72HRC value... No where near enough carbon in the kawagane to go above 60-ish. 72 HRC can't even be acheived with plain carbon steel. To get that high up you need a lot of big mean hard carbides in there.." ===============================================================================
I wonder about the same thing. Decades ago, I had heard favorable words about these swords. Cutting machinegun barrels (btw, gun barrels are not always made real hard), etc. That they performed well and were quite popular. Are such still available? Well, that one (link) was one. Saw mention of another in good condition but for about $11k. And another that was in bad condition, for about $1,100usa.
RinC
btw, I also send Wang-katana2011 a message with the link and asking them what they thought about making blades that way (low carbon rod inside a high carbon pipe).
In China, the sword business has gotten very competitive with more businesses having to share the same pie. One might think some sword factory would be willing to try, to see if they could make such, and to see if such would sell. Novelty factor if nothing else. Personally, such a blade...if successful...would be the only reason I would be tempted to buy another sword...other than the improbably event of finding a good nihonto in a garage sale for peanuts...(unlikely event...did see a couple katana in a garage sale....but alas, wall hanger junk would be as kind a description as they deserved.)
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Post by Beholden on Oct 20, 2014 22:25:24 GMT
Biggest problem you're going to face in this situation is the incredibly high possibility of a bad weld... Trying to get enough flux into a tight space of 36" - 48" in length is not going to be easy. These Kow Isshin swords are still available, and quite affordable, when you find one. Most Nihonto collectors will pass on them, leaving them to the martial arts community...
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Post by Jussi Ekholm on Oct 20, 2014 23:44:48 GMT
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Post by LastGodslayer on Oct 21, 2014 10:51:45 GMT
Thanks Jussi. I see no mention of the hardness scale in the text you linked to. And if that is in HRC then we have been fooled for decades as the mune on these blades is plenty hard (as hard as the edges in many modern european blades). Anyone can confirm the hardness values are in Rockwell C?
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Post by Jussi Ekholm on Oct 21, 2014 11:35:33 GMT
I think there might have been translation errors somewhere as I've seen these blades being referred being 72 HRC in some places.
The table at Ohmuras site was measured by Dr. Tawara of Tokyo Imperial University and shows that K o a (Kult of Athena comes up?) Isshin blades have HRC of 57. The reason why it might be confusing because there are several values measured on the both sides of the edge (omote/ura). The average of the hardness values measured of the edge is 57. The highest value measured on a single spot was the 72. However the lowest value measured was 50 and the blade averaged at 57.
I can't see why a modern production sword would need to be done with a method like this. Basic mono steel blades are already affordable to make and they are damn tough. What I would really focus on would be mostly the shape and overall quality of the sword, which I find usually lacking. In my opinion well balanced sword of quality fittings is far more desirable than a plain & rough cutting beast.
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Post by aussie-rabbit on Oct 21, 2014 11:47:53 GMT
Agreed - (pause) the listed steel -
For the technically minded, the skin steel (kawagane) is Carbon: 0.57%, Manganese: 0.05%, Silicon: 0.17%, Phosphorus: 0.018%, Sulphur: 0.003% The core steel (shingane) is Carbon: 0.23%, Manganese: 0.15%m Silicon: 0.21%, Phosphorus: 0.020%, Sulphur: 0.008%.
I'm not sure if silicon was an additive that far back, but it does sound like the type of steel you would use for rail lines, I'm not sure you could get 72HRC with even a sub-zero quench, even 62 is a big ask in the middle of a war.
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Post by aussie-rabbit on Oct 21, 2014 12:01:08 GMT
Makes one think, 5160 core with a T10 outer ? 1045/1060/1095 ? 9260/tungsten ? :lol:
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Post by LastGodslayer on Oct 21, 2014 18:39:50 GMT
A pipe blade seems like a way to avoid variance in quality when mass producing the blades. Now, if these blades did reach 72 HRC at any point and were durable, functional weapons, then we are looking at a significant increase in wear resistance not to mention the simple fact the edge is plain harder.
I'd love to see a f2/s7 mantetsuken...
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Post by Jeffrey Ching on Oct 22, 2014 9:41:14 GMT
I actually started wondering how they measured the rockwell value of muramasa blades... It's not like they're going to drop a steel ball on it.
I have to go with the rest., 72 HRC is starting to sound unbelievable. With a steel that resembles 1060 as kawagane, getting above 62 HRC is already magic. I truly have no clue how one would reach 72 HRC expect quenching in fairy poop.
Does anybody have any info about the hardness of 1060 prior to annealing? The article doesn't really explain the quenching and annealing process so perhaps they're doing something completely different.
I also know some knife and blade makers that do multi quenching. Apparently this will change the crystallization but often results in a crack. Perhaps Mantetsu (and muramasa) found a way to utilize this to go beyond the 60 HRC mark.
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Post by LastGodslayer on Oct 22, 2014 10:56:48 GMT
I'm also wondering how they tested a Muramasa since I know they were not even subjected to test cutting due to the remote chance of being damaged. HRC testing damages the blade.
Its not impossible that some micro alloying took place due to the nature of tamahagane and since it contained titanium (strongest carbide former) maybe the very edge is rich in titanium carbide which raises the hardness to such an incredible value...?
By the way, if by annealing you meant tempering after hardening, the maximum theoretical value is around 67 HRC for 1060 steel (fig. 95, pag 99; Aços: Caracteristicas e Tratamentos ~6ª Edição, Pinto Soares, Rocha Artes Gráficas) If you mean the annealing (softening) before hardening well it depends on how you got the steel from the factory (as forged, cold worked, hot worked) but it'll be a fairly low value (sub 30 HRC).
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Post by aussie-rabbit on Oct 22, 2014 11:43:15 GMT
I wonder if anyone is interested enough to try this method on a small scale - say a foot of T10 or 1095 with a 1045 or 1060 core ?
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Post by LastGodslayer on Oct 22, 2014 13:14:06 GMT
I'm Jussi on this one though. Blade construction techniques like this will provide only a small performance increase (if any), while the shaping of blades still leaves much to be desired. Still, if this is truly a better way to make "kobuse" style blades, I hope the chinese forges pay attention. I mean, you could make very long pipe forged rods, cut them in sunobe size and forge from there, lowering production costs whilst improving quality...
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Post by Robert in California on Oct 22, 2014 14:56:08 GMT
Jacky of Huawei says he is willing to try to make a KoaIsshin blade. But does not have gunto furniture (so it would be a KoaIsshin blade in regular sword furniture...which is what I would much prefer anyway). RinC
=================================================== Sorry about how KoaIsshin (notice it comes out ok with no spacing between the two words) becoming a link to KofA...."smart editing" I guess. /s RinC
But Jacky says he is willing to try to make a KoaIsshin blade. Now I know what I will ask my wife for Christmas. Or might even get so tempted as to put my folded 1095/mono T10 eye candy sword up for sale.
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