Nihonto Performance Lessens in Cold Weather
A Test by Omura Kunitaro
1) Norimitsu katana, ni-ji mei, Sue Bizen kazu uchi mono, bent upon a single cut. (This blade was the first tested and it was at normal room temperature ) |
2) Norimitsu katana, (Blade from test 1) After it was conditioned to -60 ° C, it was broken when struck.
3) Tadamitsu katana, Bishu Osafune Tadamitsu, Meiou 3rd year 2 month day, a well made sword with horimono, conditioned under -60 ° C, broken when struck.
4) Masaiye tanto signed Mihara ju Masaiye, era Choroku , conditioned under -60 ° C, bent and large ha-gire when struck.
5) Yamato-mono katana, mumei, Oei period, conditioned under -60 ° C, bent and large ha-gire when struck.
6) Muramasa tanto, mumei, 2nd generation, conditioned under -60 ° C, bent when struck.
7) Mino-mono wakizashi, mumei, Oei period, conditioned under -60 ° C, bent when struck.
8) Morimasa wakizashi, Bishu Osafune Morimasa, Oei 21 year 2 month day, conditioned under -60 ° C, big and deep shinae occurred on the ji when struck.
9) Mihara-mono katana, mumei, Tenbun period, conditioned under -10 ° C bent with three large ha-gire when struck. One of these ha-gire caused the blade to break.
10) Sue Shimada-mono tanto, mumei, conditioned under -60 ° C broken when struck.
11) Shinto Seki mono, mumei, heavy and thick tanto, conditioned under -15 ° C broken, one big mune gire and three ha-gire when struck.
12) Signed and dated gendai tanto, by Toukoto in mid autumn of Showa 11, modern steel alloy of Tungsten and Molybdenum, conditioned under -60 ° C bent when struck.
The above sword breaking tests are evidence that Nihonto do bend or break under extremely low temperatures. The cutting ability should be the first consideration for a Nihonto. Its beautiful appearance comes in second. A true Nihonto should fulfill the first requirement of being a weapon and that is to cut well. The beautiful appearance is only secondary. Art-sword theorists have the priority of this all wrong.