Mad About Science: Japanese Swords

By Brenden Bobby
Reader Columnist

Anyone that’s ever spent five minutes around anime or watched a Kurosawa masterpiece is familiar with the katana: that majestic curved samurai sword that knows no equal. It’s a thing of deadly beauty, a status symbol, something dumb teenagers in North Idaho really shouldn’t be trying to cut down birch trees with (I’m looking at you, 15-year-old Brenden.)

What most people don’t know is that the katana isn’t the only Japanese sword, it’s one of many, a few of which we’ll get to explore today.

So why do people revere Japanese swords like the katana so much more than their western counterparts? It’s all in the craft. Swords crafted during and after the Heian period (794 AD-1185 AD) were created by folding steel repeatedly over the soft core of the blade. Folding the steel 20 times over itself removed impurities, strengthened the blade and homogenized the metal throughout the blade. The importance of that last bit cannot be overstated: If your sword broke in the heat of battle because of an impurity, you were dead.

Ever wonder why the katana is curved the way it is? Most English swords are straight, while swords in the Middle East like the scimitar are curved almost into an arc. It’s designed to have as much cutting area as possible to magnify its damage-dealing ability, but not curved so much that it would take more than a fraction of a second to draw from its saya (sheathe.) The curve’s effectiveness is amplified by the way samurai would strike with their sword, twisting their palms in an action called tenouchi.

Every piece of a samurai’s sword had its place. Much of the weapon is ornamental to the untrained eye, and the untrained eye was often the first one to be plucked from the head. Blades were custom-built for their wielders, and as such often displayed colors and imagery that matched the wielder’s clan and rank in society. The ornaments weren’t just for show, though. The ornaments along the side of the tsuka (sheathe) were called menuki, and they were placed strategically as anchor points for the palm to grip in combat, much like the stitches on the crest of your favorite pigskin.

Even the tsuba (crossguard) was designed with balance in mind. Not only did they serve the practical use of stopping the owner’s hands from sliding across the blade if he chose to impale someone, but they centered the balance of the blade and allowed for smooth and precise cuts. The most important piece of the weapon, aside from its cutting edge, was the habaki. The little gold ring-looking thing above the tsuba that locked the crossguard in place. It was also fitted to the sheathe which kept the blade in a fixed position and not flopping around. Popping the habaki was seen as a threatening action, similar to cocking the hammer of a revolver or chambering a round.

The katana wasn’t the only weapon in the samurai’s arsenal. The tachi preceded the katana by a few hundred years, though it looks very similar. Around the 12th century, during the Mongol invasions of Japan (the same invasions that birthed the dreaded phrase: kamikaze, or God/divine wind), tachi began to evolve to become thicker and more lethal, likely in response to heavier Mongol armor and strong cavalry presence. The biggest difference between the tachi and katana is how they are sheathed.

While sheathed, samurai wore the katana with the cutting edge facing upward, while they wore the tachi with the edge facing down. Having your primary weapon sheathed upside down may look funny at first, but it made a lot of sense with use. When drawing a blade, you could attack and defend in the same stroke with an upward-facing edge, whereas the tachi would require a second movement after unsheathing in order to strike. As well, while having an upward-facing blade, the cutting edge never succumbs to gravitational wear inside of the sheathe. There is an entire school of martial arts surrounding the art of drawing your sword like this, called Iaido, and it’s really cool to watch. As well, it’s believed that some techniques of the martial art Aikido were developed in relation to drawing the sword this way (in a defensive manner.)

The zanbato was the equivalent of a western claymore, reaching blade lengths of almost three feet. These weapons were also likely developed in response to the Mongol invasions during the 12th century, though its conception originates from mainland China. The weakest point of a horse is its legs, and samurai were able to use the massive cutting edge of the sword to relieve charging horses of at least two of their legs. These fell into decline later into Japanese history for a few reasons. During and after the warring states period, Japan suffered frequent civil wars. During this time, the common man wasn’t permitted to carry weapons or armor, and horses were an extreme expense available only to the highest classes of samurai and daimyo. Who needs a horse-slaying weapon when you have no horses to slay? Nevertheless, the zanbato left its mark on Japanese culture and now permeates through video games and anime around the world. I mean, bigger is better, right?

Sayonara!