Hamon Question...

J

joeshredd

Joined
May 8, 2002
Messages
2,254
Okay, this is for the steel experts, so I thought I'd ask here...

In the following thread, an amazing Hamon has been created that apparently the maker seems to be able to achieve regularly. Now, I know what a hamon is and the rudiments of how it is created...

http://www.bladeforums.com/forums/showthread.php?t=373391

My question is this: does the orientation of the grain structures evident in such blades affect the performance of the blade???

Ie; does the orientation of the grain relative to the pressures exerted in, for instance, chopping, create or defeat stresses such a blade would experience?

I'm not sure if I'm being real clear on my question, but from having enjoyed looking at hamons since I saw my first true Japanese sword, and now seeing all these modern blades exploring the boundaries of grain developement and strucure, I've always wondered if the direction or orientation of the grains added or detracted from the performance of the blade...

Any ball park answers?? :confused:
 
The japanese don't seem to have had any problem with it ! In use the sword blades usually failed by the creation of nicks which initiate cracks which propagate.That all occurs on the martensitic edge.
 
A hamon is achieved by differentially hardening the blade .Traditionally the japanese blade has clay applied to the spine so the spine cools slower than the edge when the blade is quenched.You can also quench just the edge and get a similar effect. A low hardenability steel has to be used .It will not work with an air hardening steel or many oil hardening ones also.With the clay you can be very creative with the design. The hamon shows up because the edge has a structure of martensite and the spine a structure of pearlite . The two polish and etch differently.
 
Thanks for responding...

I guess my curiosity really revolves around the more aggressive hamons that develope the different crystalline structures in a pattern that is almost perpendicular to the cutting edge. I realize some of the traditional Japanese schools of forging all were characterized by their relatively unique patterns, but most of them don't seem to have as aggressive of curves or angles in the banding as a lot of modern examples we're seeing on these forums... except possibly where the hamon curls up towards the tip of the blade and then bends back across the spine of the blade. Maybe one of the reasons I ask this is that the tips of a lot of ancient Japanese swords broke off, and were subsequently remade as a Tanto, or the stub of the sword was remade into a Waki. Was this due to the structural result of the creation of the Hamon? Statistically, I dunno if this could be tested, but it does pique my curiosity...

Oh well, I don't think I'll ever have to worry about any of my blades with any sort of hamons breaking... heck, I'd wear out before any of mine would fail!

Thanks guys!

:D
 
You must log in or register to reply here.
Back
Top