Blade strength: Kaze v. Hanwei Ninjato
by Steven Philippi
QUESTION: In both of your articles you mention that both the Kaze and the Hanwei Ninjato are differentially hardened. Between the two swords which has the most resilient blade, which is "sharper" and which has the hardest edge? I have heard the Ninjato has a rockwell of 60 do you know what the Kaze has? Also, I own a Tenchi and love it. You say that the Kaze is not as tough as the Tenchi, but by how much? What is pushing the limit in cutting and abuse with the Kaze when compared the the Tenchi.
ANSWER: Hi Steven,
The Hanwei Ninjato does indeed have a HRC around 60, while the Kaze is in the high 50s. (approx 57-58). Not much of a difference there, but the spine of the Kaze is in the high 40s too while the Hanwei is closer to 40...
No big difference there, but the Ninjato is quite thin and essentially 'brittle', while the Kaze has an appleseed profile (Hira Niku) which makes it more resiliant overall...
The Ninjato is a tad sharper out of the box (if you buy it from a good seller) while the Kaze is only supposed to be sharp enough for Tatami (though it is often much sharper, as seen in my tests).
Hmm, rather than complicate things - the easy way to have said all this is that the Kaze is more durable overall, but not quite as sharp. ;-)
Now, as to the Kaze not being as durable as the Tenchi. The reason for this is that as it is differentially hardened - if it encounters a lateral force it can take a set as the spine and edge of the steel will try to return to center at a different rate.
The Tenchi on the other hand, being all the same hardness all the way through - will just bounce on back.
If compared to the Tenchi, you'll find the Kaze has a harder and sharper edge. But it just can't take the same kind of abuse the monosteel Tenchi can.
Hope this helps. :-)