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Old 05-05-2005, 08:49 AM   #33
Keith Larman
Dojo: AIA, Los Angeles, CA
Location: California
Join Date: Apr 2005
Posts: 1,604
Re: A warning! Not the chen swords!

George S. Ledyard wrote:
see this article:

it's quite interesting...
Yup, interesting read.

And for those who read it, I have to point something out. While they are trying to dispel the myth about blood grooves they manage perpetuate a completely different common myth. They talk about bo-hi (fullers) using the same misunderstanding of I-beams that most people have. The statements about "stiffening" and not sacrificing any strength are simply incorrect. You cannot remove material without sacrificing strength. It simply doesn't work that way. The issue is more about strength to weight ratios and also removing mass in such a way as to *minimize* the loss in one dimension. Bo-hi are fantastic in how they lighten in that they minimize the loss of rigidity along the vector you would use cutting. But you still lose some. Always. Period. Rotate the blade a bit during a cut and the blade will be more susceptable to bending than it would have been had the bo-hi not been carved in. So it is *not* as strong and certainly not stronger. But if you keep your hasuji proper it will be *almost* as strong and lighter. Just don't pooch a tough cut...

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