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Swords, Cutting and Military History

Aratameshi: Testing blades to destruction

Aratameshi: Testing blades to destruction

photo by wbeem

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In proving the ability or superiority of their blades, smiths and swords owners of the late Tokugawa era (known as the Bakumatsu Period) would engage in what we today would call destructive testing; to test a blade against various heavy or solid  materials to see if the blade was capable of cutting said material without damage.

This included the cutting of heavy bamboo, deer antlers, hardwood branches or staffs, and even slapping the blade flat against the surface of water to see if it would survive the shock ( Extreme Aratameshi );  blades of lesser quality would bend, chip, break or simply shatter under such treatment.

Unlike tameshigiri, which in this period was used as a test of the cutter’s skill and technique, many forms of aratameshi would test the blade on harder or heavier materials until it broke.  Both Extreme Aratameshi and Lowry’s The Essence of Budo suggest that this practice came more from a urgent sense of need to prove the ability or superiority of nihonto over the strange weapons European traders and missionaries  brought with them via the Black Ships.  These were (at least at first) the Portuguese trading vessels which were allowed to land in Japan, starting in 1543;  the Portuguese ships were coated with black tar, thus the name.  Eventually all European trading vessels came to referred to by this moniker.

Early in Bakumatsu, at least one smith was tracking the effectiveness and durability of nihonto in actual use ( Suishinshi Masahide and the Functionality of Nihonto ).  In this translated work, the smith tracks the 25 accounts from eye-witnesses who saw the blades in action.  Swords are recorded as bending, breaking and even one which “shattered like an icicle”.  Here are just a few of the events recorded:

  1. A family in Shinano had collected more than 150 pieces of broken katana, yari, and naginata of from battlefields in the koto period.
  2. An Okayama retainer named Watanabe was doing a cutting test on the lower part of a corpse. The katana broke at the monouchi area. It was a Seki blade.
  3. A bandit attacked the leader of Okayama retainers. The leader used the mune side of a katana to fight the bandit but it broke. He then picked up a bamboo stick and continued to fight. Eventually, he was able to defeat the attacker and used a rope to tie him up. When the retainer checked the bandit he found wounds caused by the bamboo stick but none by the katana. He couldn’t help but to laugh at the situation.
  4. An Okayama retainer got into an argument with a person on a ferry. He drew his katana and made a cut. The blade caught the wooden pole of the boat and broke at the monouchi.
  5. A Bushi from Mito was doing a cutting test on a skull. The katana broke. A Mito swordsman was fighting with a Bushi. His katana broke about 27cm from the kissaki. It was a Hizen mono with hiro (wide) suguha. Suishinshi Masahide documented the above examples.


Slightly later in the period (1853) several accounts record aratameshi details:  this, from Extreme Aratameshi:

The testing commenced with Tsuge Kahee, a naginata teacher, wielding an ara nie deki katana by Taikei Naotane made in 1835. Two bamboo sticks were wrapped together and used as the testing object. The circumference of each bamboo stick was about 15 cm each. When the blade struck the target, it penetrated about 80%. This was not a complete cut. Then, a retainer named Saitomasuki tested this katana on a piece of metal that was 0.24 cm thick and 9.0 cm wide. The blade broke in two at the area close to the hamachi. The broken edges looked similar to that of an icicle, very brittle. This katana had been considered well made.


The second blade tested was also a katana by Naotane. This blade had a nioi-deki hamon. It should not break as easily as the first one. After several cuts by Tsuge Kahee on straw wrapped bamboo sticks, a ha-giri developed and the blade was bent. Five other people also tested the katana but none of them could make a complete cut on the straw wrapped bamboo targets. Takano Kurumanosuke then took over the testing and used the katana to cut a helmet filled with iron sand. Another bend developed upon the first cut. Two more cuts introduced another ha-giri. Deer antlers were used as the next target and three cuts were performed. A piece of forged iron was also used for two cuts. This cutting of hard objects produced many ha-giri. After that, Kanekochubee cut a kabuto with it and a severe bend was introduced. He then used the blade to hit an anvil on the mune and on the sides several times and the blade broke.

It should be mentioned that the cutting of helmets as a test of a sword’s strength was known as kabuto wari (kabuto being the name for a helmet);  in this, the helmet would be filled with sand, metal filings or dampened silk.  The filling was to both add weight and resistance to the helmet — duplicating a head —  and to prevent the helmet from bouncing so the sword would not snap ( Thoughts on Tameshigiri from Famous Swordsmen – section on Takano Sasaburo – Helmet Cutting).   The practitioner would attempt to cut as deeply into the helmet and filling material as possible. Today, kabuto wari is practiced by some martial artists, and is enshrined within iaido in the form of certain kata.

The modern-day record for kabuto wari is held by Obata Toshishiro Sensei.    A modern kabuto wari testing event in Europe can be seen in the following video:



In 1937, the Japanese Army — at the time caught up in winter fighting in Manchuria — sought the assistance of the publisher of Token Kogei (Sword Industry) magazine, Omura Kunitaro in conducting tests to see the effects of extremely cold weather on nihonto ( Nihonto Performance Lessens in Cold Weather );  the implication being that they were seeing problems with officers using swords in the Manchurian cold.

In this test, the blades were pre-cooled to -60 degrees Celsius, then placed on two pillows and struck with a hammer.  As can be seen in the photograph from the report, below, this test conclusively showed that extreme cold had a definite negative effect on the blades, with some bending, developing cracks or breaking when struck.


Bent and broken blades from cold test

Bent and broken blades from cold test, photo from Nihonto Performance Lessens in Cold Weather


Today, some modern practical cutting sword reviewers take an aratameshi approach to testing sample blades, either to make a point of the toughness and durability of the blade in question, or to highlight any issues with blades from various manufacturers.  There are quite a number of such videos available on YouTube for those who wish to view them



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