Katana: A Guide to the Most Popular Japanese Sword

The curved, single-edged katana is the weapon most associated with the samurai warriors of feudal Japan. However, the samurai sword was more than a weapon—it served as a status symbol and work of art. Throughout the world, sword collectors and enthusiasts admire Japanese blades for their craftsmanship and aesthetic qualities.

This article discusses the history of the katana, its metallurgy, its unique characteristics, and what sets it apart from other Japanese swords.

Characteristics of the Katana Sword

The Japanese katana sword is an extremely resilient and lethally sharp weapon. Unlike other swords, katana blades have several aesthetic features, especially the hamon or temperline patterns. Here are the unique characteristics of the samurai sword:

Type of Steel

Japanese swordsmiths are also iron producers, and they obtain the raw material for Japanese swords from the surrounding environment. They craft the katana swords from tamahagane, carbon steel made from the traditional tatara furnace. Unlike any other type of steel, the tamahagane is smelted from iron sands or satetsu for several days to even out its carbon content and remove impurities.

Many swordsmiths today strive to reproduce the craftsmanship of past masters using traditional techniques. Modern katana replicas often feature high carbon steel or damascus steel blades. However, these replicas are not made from tamahagane steel, and swordsmiths often use modern steel-production methods to craft them.

Blade Structure

The challenge for Japanese swordsmiths was to produce a blade hard enough to retain its cutting edge but flexible at the same time to withstand heavy blows. The more carbon content it has, the harder the steel will be, but it comes with a price as it also makes the blade brittle.

Hence, they crafted sword blades with a softer spine for shock absorption and a harder cutting edge, contributing to its durability and flexibility. Katana blades are clay tempered, in which the swordsmith covers the blade with clay to ensure that the edge hardens more than the spine during the tempering process. 

Blade Appearance

The Japanese swords are known most for their curved blades, which also have several aesthetic features that make them a work of art. Most sword collectors value the hamon or the temperline pattern on the cutting edge. The blades also have a distinctive appearance and grain patterns on the surface.

Curvature or Sori

The katana blade has a shallow curvature that may be at the center, near the tip, or toward the hilt. Experts determine the sword blade curvature by measuring the distance from the back of the blade to an imaginary straight line, drawn from the tip to the hilt, excluding the tang.

Temperline Pattern or Hamon

Katana blades are clay tempered, resulting in a natural hamon, the visible pattern along the cutting edge. These patterns show the boundary between the softer and hardened part of the blade. Collectors value a katana blade with a good hamon which does not have gaps or breaks in the boundary line.

The hamon is considered the fingerprint of a swordsmith, as creating a distinctive pattern requires skill and experience. The hamon can have straight or irregular lines. The hitatsura has a wild and rugged look, making it the most striking of all types.

However, replica swords do not have a genuine hamon, but only an etched temperline pattern. A real hamon shows specks or dots along the borderline while an etched temperline is often smooth and lacks internal features.

Steel’s Surface or Jigane

The traditional katana blade is often darker than modern steel and is not reflective. When examining the surface, there’s a difference between the whitish steel color on the cutting edge and the grayish steel color on the other side.

Grain Patterns or Jihada

While forging the katana blade, the swordsmith repeatedly folded the steel, resulting in a distinct grain pattern called jihada. Depending on the technique, the grain patterns may feature straight lines, wavy lines, swirls, or a mix of linear and circular motifs.

Size and Length

Japanese blades generally have the same construction, but are classified according to length. The katana generally has a blade length of over 60 centimeters, with its hilt around 20 to 25 centimeters long.

Sword Mounting

The samurai often changed their sword mountings to flaunt their style and personality. In some cases, these accessories can be valued similarly or more than the katana blade.

Hilt or Tsuka

The katana has a hilt that can be used with one or both hands, though samurai warriors often used a two-handed grip for full power. The tsuka is usually covered with samegawa or shark skin, sometimes ray skin to provide a secure grip for the user.

The Japanese sword generally has a full tang blade, in which the tang would be enclosed within the hilt. Traditional katana blades have the mei or sword maker’s signature inscribed on the tang.

Often with matching designs, the fuchi and kashira protect both ends of the hilt. The fuchi is the collar next to the sword guard, while the kashira is on the pommel. On the other hand, the menuki is the metal decoration placed under the hilt wrapping.

Sword Guard or Tsuba

The most functional accessory of the katana, the tsuba is the sword guard that protects the hand of swordsmen. Sword guards are usually disk-shaped, but others are rectangular with rounded corners. There is even a four-lobed shape called mokko.

The tsuba is functional and decorative, as some artisans even crafted elaborate designs that served as family heirlooms. Many tsuba artisans used gold and silver, as well as colored stones. The sukashi tsuba has a decorative cutout design, though it may not be suitable for battle.

Scabbard or Saya

The katana comes in a scabbard or saya, often made of wood. To be placed in a saya, the sword has a collar called habaki, supporting the hilt. The katana is mounted in either shirasaya, a simple wooden scabbard, or koshirae, a lacquered scabbard with several metal ornaments. The samurai carried the katana through the obi sash. Sometimes, they fastened it to a sword carrier or koshiate attached to a belt.

Facts About the Japanese Katana

The katana served both as a weapon and the soul of the warrior. No samurai would ever be without his katana, so the sword would tell the world that its owner was a social and military elite. Here are the things you need to know about the samurai sword:

The samurai wore the katana with the cutting edge facing up.

Designed to deliver powerful slashing attacks, the samurai wore the katana with the blade facing upwards, which allowed drawing and cutting with one stroke. The katana can be distinguished from the earlier curved tachi based on how the warrior wore his sword. The earlier samurai wore the tachi slung from a belt with the cutting edge facing down, which required two motions to wield the sword.

The samurai wore the daisho, a sword set of katana and wakizashi.

The term daisho translates as large and small, in reference to the longer sword katana and shorter sword wakizashi. It comes from the Japanese words daito or long sword and shoto or short sword. The shorter version of the katana, the wakizashi measures around 45 centimeters long. It served as a secondary weapon when katana was not allowed upon entering public buildings.

The meaning of long sword and short sword changed over centuries.

Today, swords of more than 2 shaku, approximately 60 centimeters, are called daito or long swords. On the other hand, swords shorter than 2 shaku but longer than 1 shaku, approximately 30 centimeters, are called shoto or short swords. Hence, the katana is considered a long sword and the wakizashi a short sword. Also, the tanto is a dagger with a maximum length of 1 shaku.

Swordsmen used wooden swords in training to preserve katana blades.

In the Muromachi period, martial arts training became common, so swordsmen wielded wooden swords called bokken to practice their sword fighting skills while preventing injury and preserving the katana blades. However, wooden swords also served as a weapon for actual combat. In the famous Japanese legend, Miyamoto Musashi defeated his opponent Sasaki Kojiro with a bokken.

The samurai followed a strict code of honor and discipline.

Carrying the katana and wearing the correct armor were vital aspects of being a samurai. But apart from military skills and fearlessness, the samurai followed a strict code of conduct known as bushido, emphasizing loyalty, honesty, and self-discipline. Today, bushido serves as the basic code of conduct for Japanese people.

The katana blade is longer than a ninjato or ninja sword.

The samurai sword had curved blades, but the ninja relied on straight, shorter blades. The ninjas were also more orthodox in using their swords. The ninjato handle was longer than the tsuka of a katana and had a stronger sword guard, which provided a step when climbing walls. As a multi-functional tool, ninja scabbards were also traditionally plain.

Katana Sword vs. Tachi Sword

Both Japanese swords are curved and single-edged, but katana blades tend to have a shallower curvature compared to tachi blades. Katana blades measure over 60 centimeters long, while tachi blades have extremely varied lengths, depending on the military strategy of the period. Still, the tachi is a longsword, measuring around 44 to 67 centimeters in length. Also, the katana served as an infantry sword, while the tachi functioned as a cavalry sword.

Swordmakers shortened many tachi blades so samurai could wear them in katana style. Collectors may determine whether a Japanese sword was a katana or tachi by examining the swordsmith’s signature or mei on the tang. Katana had the mei on the side of the tang on the outside of the sword when carried. On the other hand, the tachi had it on the opposite side. However, shortening of the blade sometimes cuts off these signatures.

Katana Sword vs. Naginata Polearm

The Japanese naginata is a polearm, though its blade is similar to the forging and construction of katana blades. Early naginata blades were large, broad, and deeply curved, measuring about 30 to 76 centimeters long. Later blades tended to be smaller, shorter, and less curved yet had a wooden shaft of approximately 180 centimeters long. 

Many bladesmiths occasionally shortened and reshaped the naginata blades. Like the katana, the polearm had a tsuba or guard, usually small, though others were of the same size found on samurai swords. Some naginata blades had their maker’s signature on the tang and a mekugi peg secured the tang into the pole.

The Japanese foot soldiers used the naginata as their primary weapon, though by the Sengoku period, the yari replaced it. The naginata required broad sweeping motions, which became impractical in later warfare.

History of the Katana Sword

The oldest Japanese swords were straight—the single-edged chokuto and the double-edged tsurugi. However, changes in military strategy had created the need for different types of swords. Early samurai had used the longer and deeply curved tachi from horseback. Eventually, samurai generals preferred infantry tactics compared to mounted cavalry, making the katana the preferred sword.

In the Muromachi Period (1338–1573)

Within the Muromachi period emerged a century of military struggle known as the Sengoku period, the Age of the Country at War. During the tumultuous period, the uchigatana developed out of the need for speed in combat. The samurai wore their uchigatana edge-up in their belts, making it easier to draw and strike compared to the earlier slung tachi that required two actions to wield the sword.

At first, the uchigatana complemented the tachi, but it later became so popular that it replaced the tachi. Eventually, swordsmiths started to forge uchigatana in short and long lengths. The shorter blades were called wakizashi, while the longer blades were called katana. The wearing of paired swords, one long and one short among the samurai class also became common.

In the Momoyama Period (1574–1600)

During this period, sword mountings became very expensive and elaborate. Swordsmiths started incorporating precious metals, lacquer, and other materials to crafting tsuba, sword fittings, and other metal ornaments such as fuchi, kashira, and menuki. Some uchigatana remained simple and functional for combat, but those heavily decorated were commonly gifted to high-ranking samurai.

In the Edo Period (1603–1867)

During this period, the daisho, a sword set of katana and wakizashi, became the symbol of the samurai class. Still, merchants carried the short sword for self-defense when traveling. The design of the daisho also had regulations when worn for formal or ceremonial use. So, a wealthy samurai would have had several sword fittings for a single blade, choosing the most suitable for a given occasion.

In the Meiji Period (1868–1889)

In 1868, the Meiji Restoration led to the abolition of the feudal system, so the samurai also lost their privileged position. The emperor regained power and formed a national army, which conscripted men from society. In 1876, the Meiji government issued the Hatorei edict, which prohibited the carrying of swords in public. The government also began to modernize the Japanese military, so the katana swords were no longer practical for modern combat. 

The Katana Sword in Martial Arts

The katana is the best-known Japanese weapon with many using it in martial arts today. Here are the Japanese martial arts that utilize the katana—or other alternatives that replicate the qualities of the real sword.

In Kenjutsu

The katana is the defining blade of kenjutsu, which focuses on the traditional Japanese art of sword fighting. The samurai practiced the sword art since the 4th century CE, but it began to decline in the late 1860s due to the invention of firearms. Still, the Japanese military revived the interest in sword fighting skills, making it relevant to modern times.

Today, kenjutsu practitioners train with a wooden sword called bokken, roughly the same size and weight as the katana. The wooden sword allows the practitioners to practice sword fighting without the risk of injury or death.

In Kendo

The modern equivalent of kenjutsu, the kendo focuses on balance, speed, and fluidity in its techniques. Since the fighter’s goal is to end the combat as quickly as possible, training requires targeting areas such as the head, neck, forearms, and abdomen.

Instead of a real katana sword, kendo practitioners use the bamboo training sword shinai when training in pairs. The shinai, a bundle of bamboo strips bound together, is a safer alternative to the steel katana and wooden sword. Training in the kendo dojo uses the bokken.

In Iaido

The iaido involves perfecting the control of the katana sword. The sword art trained the warrior for a surprise attack so he could respond instantly. In the older iaido, practitioners would use wooden katana or bokuto. However, a practitioner would not benefit from the saya practice since a wooden sword has no scabbard.

Today, iaido practitioners use iaito or blunt katana blades in training but never in contact drills. Modern iaido is a non-competitive art, though some competitions require participants to perform sword movements in front of judges.

In Battōjutsu

Also referred to as iaijutsu, the battōjutsu focuses on quickly drawing the katana from the scabbard and warding off an attack. Unlike other martial arts, the movements in battōjutsu are smooth, controlled, yet instantaneous. Practitioners often start practicing with a mock sword with an aluminum alloy blade and later with the real katana sword.

In Toyama Ryu

The Toyama Ryu focuses on the practical application of the katana sword. It is a relatively modern sword art, but its principles draw from the philosophy and techniques of the samurai era. Today, it remains relevant for its alternative perspective to Japanese swordsmanship.

The Japanese Imperial Army created the sword art out of necessity because soldiers had to master swordsmanship quickly without years of study. After observing the European close-combat techniques in World War I, they adapted the moves for the katana on the battlefield.

The Katana Sword in Pop Culture

Today, the samurai katana sword serves as an inspiration for several fictional swords in anime and films. In cosplay and LARP, many dress up as samurai or play the role of their favorite character wielding the sword.

The most popular is the sakabato or the reverse blade katana from Rurouni Kenshin, also known as Samurai X. In the story, the character Himura Kenshin is a former assassin who atones for his past, so he wields a reverse-bladed katana to prevent bloodshed.

A contemporary swordsmith in Japan even crafted the first real-life version of the sakabato, featuring a natural hamon, sharp cutting edge, and the death poem of Arai Shakku, master swordsmith who forged Kenshin’s sword, on the tang.

Are Katana Swords Illegal in Japan?

Ordinary citizens can legally own a katana, but the sword must have cultural or historical significance. It has to be registered with the Nihon Token Hozon Kai and comes with a certificate of authenticity and permit, which has to stay with the sword at all times. The rule applies to antique and newly made katana swords by licensed swordsmiths.

However, decorative and training swords like iaito with zinc-aluminum blades that cannot be sharpened are exempted. In Japan, the katana is under the Firearm and Sword Possession Control Law, which forbids individuals from carrying the sword out in the open. One may get a permit to have a katana sword for home ownership, but it has to be kept in the house.

The Japanese government also allows licensed swordsmiths to produce a maximum of two long swords per month, and only traditionally made Japanese katana forged from tamahagane—can be licensed. On the other hand, unlicensed katana swords or ones crafted by unlicensed swordsmiths are confiscated and the owner charged with possession of illegal weapons.

Care and Maintenance for Katana Swords

The katana sword is a beautiful art piece, but it is also a weapon that requires maintenance. The most important aspect of preserving katana blades is to protect them from scratches and rust. Here are some tips on how to maintain your samurai sword:

Store the katana in a plain wooden scabbard.

Elaborate mountings are great for display, but placing the katana in a shirasaya or wooden scabbard makes cleaning and maintenance easier. When rust develops in areas where the scabbard touches the blade, one may split the sheath into vertical halves for cleaning and then fasten them together with a paste. When the sheath is too old, its interior will likely accumulate dirt and rust, damaging the blade. In that case, the katana needs a new saya or scabbard.

Use proper cleaning tools for katana blades.

Sword collectors also use traditional Japanese tools for maintaining their katana blades. Most opt for wrinkled Japanese paper called nuguigami to remove dusty and coarse elements on the blade surface. Then, they use the uchiko or ground whetstone powder to clean the blade, and the abura, also called choji or clove oil, to prevent rust.

Katana blades require cleaning and oiling every six months.

You may wipe the blade with nuguigami to remove dust, then pat the uchiko powder on the surface from the base toward the tip. Next, use a flannel or wiping paper to spread oil on the blade surface. Just keep in mind that it is necessary to remove stale oil and replace it with new oil every time. As long as the katana blade is stable, you may clean it regularly every six months.

Take the katana blade to a polishing specialist once it starts to rust.

Many attempt to rub the rust off with a spatula, sandpaper, or sharpening stones, but these tools do more damage to the blade surface. The katana blade is not supposed to be bright and reflective, and buffers tend to over-shine the surface. Amateur repairs often scratch the blade surface, so it is much preferred to take the sword to a polishing specialist.

Don’t do anything to the tang of the sword.

Katana swords forged by licensed swordsmiths carry their identification on the tang. Any alteration on the tang, including cleaning and rust removal, can reduce the value of the katana. In fact, the color and type of rust can help to date and authenticate the katana blade. Experts usually examine the sword blade with a clean cloth, as natural oils from bare hands also contribute to rusting.

Be mindful of how you use your katana sword.

Battle-ready katana and training swords used in tameshigiri are prone to stain and rust as many practitioners use their swords to cut tatami mats, bamboo, fruits, and water-filled bottles. Since these targets have lots of moisture and acid that can damage the blade, the katana blade should be cleaned thoroughly after each use to avoid stains from forming.

Conclusion

The samurai of feudal Japan trained in several weapons, especially the katana. Although many traditional arts associated with these warriors have disappeared, the art of Japanese sword making has persevered. Today, the katana remains significant not only in martial arts but also in Japanese culture and history.