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- Mar 26, 2002
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Great article.
Extensive.
Other related factors.
Must read.
Hey Yvsa.
http://home.earthlink.net/~steinrl/niku.htm
On Japanese blades the convex bevel is called Niku.
"SWORD BLADE NIKU by Keith Larman
The following article was written in response to a series of questions on an on-line forum on the topics of niku, blade widths, different tsurikomi (blade structure), and the effects of those things on the efficiency of tameshigiri practice.........Figure 2........Blade A, a shinogi zukuri with niku has a fairly wide angle where you could strike the target and still have support behind the edge. So blade A is most likely to not be damaged with an off-angle cut. There's more steel supporting the edge. This extra steel provides a shock absorber of sorts to the edge itself. This type of extreme niku turned out to be optimal for dealing with more difficult targets like armor and did more than just slice but also cleaved to an extent.
But because of the wider angle of the very edge on blade A, the edge won't get as sharp as Blade B or C. But it still won't dull nearly as fast as B or C because it's simply stronger with more material. The edge on B,...............
...............In Figure 3, the niku of sword A now shows its advantage. On a sufficiently thick target the very shape of the blade creates a wedge that lifts and separates the target a bit more. This combined with the shinogi-ji being either flat or pulling back toward the mune means that much less blade surface is in contact with the target. So less surface area, less friction. On a thick target the thicker shinogi zukuri blade with niku might actually feel easier during the cut even though the hira will displace the target less and is sharper!
Then if we talk about harder targets, well, the advantage of a sharper edge diminishes as.........................."
There's a -LOT- more to the article.
Extensive.
Other related factors.
Must read.
Hey Yvsa.
http://home.earthlink.net/~steinrl/niku.htm
On Japanese blades the convex bevel is called Niku.
"SWORD BLADE NIKU by Keith Larman
The following article was written in response to a series of questions on an on-line forum on the topics of niku, blade widths, different tsurikomi (blade structure), and the effects of those things on the efficiency of tameshigiri practice.........Figure 2........Blade A, a shinogi zukuri with niku has a fairly wide angle where you could strike the target and still have support behind the edge. So blade A is most likely to not be damaged with an off-angle cut. There's more steel supporting the edge. This extra steel provides a shock absorber of sorts to the edge itself. This type of extreme niku turned out to be optimal for dealing with more difficult targets like armor and did more than just slice but also cleaved to an extent.
But because of the wider angle of the very edge on blade A, the edge won't get as sharp as Blade B or C. But it still won't dull nearly as fast as B or C because it's simply stronger with more material. The edge on B,...............
...............In Figure 3, the niku of sword A now shows its advantage. On a sufficiently thick target the very shape of the blade creates a wedge that lifts and separates the target a bit more. This combined with the shinogi-ji being either flat or pulling back toward the mune means that much less blade surface is in contact with the target. So less surface area, less friction. On a thick target the thicker shinogi zukuri blade with niku might actually feel easier during the cut even though the hira will displace the target less and is sharper!
Then if we talk about harder targets, well, the advantage of a sharper edge diminishes as.........................."
There's a -LOT- more to the article.
