slav
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Post by slav on Mar 27, 2008 0:07:42 GMT
I was wondering if anyone here has ever handled or come across a katana with hira-zukuri profile?
I know that traditionally hira-zukuri katanas were very, very rare, but I have seen a few online by custom smiths including Hernandez, Sorrells, and Clark. They are supposed to be wicked cutters.
If you have handled or cut with one, please give your overall impressions...
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Post by oos3thoo on Mar 27, 2008 1:06:40 GMT
Whats the difference between this and a normal Katana?
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Post by Deleted on Mar 27, 2008 2:07:01 GMT
Seth, google is your friend.  token.cz/external/meiboku/guide/form/zukuri/index.htmIt's a blade cross section without the faceted ridge seen in normal shinogi zukuri. Actually this is an interesting topic for me because Chinese swords used both hira zukuri and something like shinogi zukuri in dao. During the last 300 years the Chinese abandoned the shinogi zukuri like style and adopted the hira zukuri as the norm.  vs.  |
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Post by Deleted on Mar 27, 2008 3:32:53 GMT
personally i like blades with a long kissaki do those blades offer anything? i think its called the Osoraku Zukuri or something like that
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Post by salvatore on Mar 27, 2008 5:07:06 GMT
A Hira-zukuri drops the ridge. They ARE supposed to be wicked cutters, they are supposedly dropped on Korean Jingum, which are virtually like katanas.
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Post by Deleted on Mar 28, 2008 4:18:10 GMT
personally i like blades with a long kissaki do those blades offer anything? i think its called the Osoraku Zukuri or something like that I have a modern knife that's designed after osoraku zukuri. I think it thrusts really well. Not as well as a double edged blade but still the extended cutting edge of the kissaki really cuts into the target well.  |
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Post by salvatore on Mar 28, 2008 4:31:02 GMT
Jeezux! Where did you get that? I want one!
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slav
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Post by slav on Mar 28, 2008 5:00:51 GMT
The "Hissatsu" made by CRKT is a modern tactical version of an osoraku tanto. It was designed by James Williams, master swordsman. Check it out:  Garret's knife is the "Hissatsu folder" version. www.crkt.com/hissatsu.htmlwww.crkt.com/hissfolder.htmlAnyways, back to the subject at hand...Hira-Zukuri katanas anyone?  |
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Post by Deleted on Mar 28, 2008 7:24:19 GMT
Im interstate atm but I think iirc theres a couple in the imperial collection of japan, when I get home ill check my references...
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Post by Dan Davis on Mar 28, 2008 12:31:53 GMT
Yes, I have cut with them in the past and have made hira-zukuri katana as custom order pieces. They do cut well on soft targets, not so well on harder or thicker targets because of drag from the wider blade. The "wedge-effect" of shinogi or shobu-zukuri configurations is lost on this type of sword.
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Post by Deleted on Mar 28, 2008 12:50:29 GMT
Dan,
I'm very interested to hear about the performance of the hira zukuri blades... could you expand some more on the wedging effect?
All too often I read about nonsense relating surface area contact with increased friction but it sounds like you have a really good appreciation of the topic!
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slav
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Post by slav on Mar 30, 2008 16:15:14 GMT
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Post by Deleted on Mar 30, 2008 17:02:19 GMT
Man, this piece sure is a monster ( not that i'd ever dare to use such a thing, i'm almost sure i'd break it soon -.- ). The last pic owns ;D
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slav
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Post by slav on Mar 30, 2008 19:01:17 GMT
Yeah, Keith's got a really cute kid. And cats.
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Post by Deleted on Mar 31, 2008 0:44:18 GMT
That is a beautiful sword |
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slav
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Post by slav on Apr 1, 2008 3:29:06 GMT
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Post by salvatore on Apr 1, 2008 3:48:10 GMT
Yeah....Wow, thats all I can say.
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Post by randomnobody on Apr 1, 2008 4:12:50 GMT
Jeebus, that's big. Fetched a mighty pretty penny, too.
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Post by Dan Davis on Apr 1, 2008 11:54:36 GMT
Dan,
I'm very interested to hear about the performance of the hira zukuri blades... could you expand some more on the wedging effect?
All too often I read about nonsense relating surface area contact with increased friction but it sounds like you have a really good appreciation of the topic! Actually, surface area in contact with material IS the reason because the increased surface area causes drag, which slows down the blade and makes it more difficult to cut through the target. As a result you need to put more force into your cut and this typically causes a loss (however minor) of form. This loss of form will result in a poorer cut, which typically requires more force to complete, which causes a greater loss of form, circular feedback loop, etc. etc. The "wedge" effect is easy to illustrate. - Go out and get a 3" square block of cheese (I like cheddar), a 3" paring knife, and a small hatchet (approximately 3 inches of blade).
- Slice a piece of cheese with the paring knife and you will note that the cheese closes together behind the edge, clamping down on the body of the blade and making it stick. It takes a lot of force to push the paring knife through the cheese and you end up with a ragged cut.
- Now take your hatchet and cut a slice. The blunt, steep angle of the hatchet head will act as a wedge, forcing the cheese slice away from the blade and cutting through fairly easily. This gives you an easier cut and a much nicer looking slice of cheese.
Chef's note: it is easier to slice cheese with a small meat cleaver than with a knife. For a more in-depth study of shape in katana look here, keeping in mind the block of cheese you should be making into sandwiches about now. |
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Post by Deleted on Apr 1, 2008 12:12:55 GMT
Hey Dan, Thanks for the info on wedging, it was a great example. I have to say though that surface area doesn't factor into drag - as drag is friction. This is a field where I'm pretty confident in my knowledge of physics. Friction is proportional to the force normal (perpendicular) to the surfaces (e.g. the wedging angle increases this but has its own advantageous properties as you've highlighted) and the coefficient of friction between the surfaces. en.wikipedia.org/wiki/Friction for more detail. A good explanation I've found which is more coherent than I could be can be found at www.physlink.com/Education/AskExperts/ae140.cfmI have also discussed this with a physicist friend of mine and unfortunately the common-held belief that niku helps due to a frictional effect is wrong - it's the wedging (splitting the target via bending) effect. Something that I can offer as a practical example is the 'feedback' felt by using a blade with niku that is not felt to the same degree as with a thinner blade - that is the force normal. |
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