Tantō

A tantō (短刀, 'short blade') is a traditionally made Japanese knife (nihontō) that was worn by the samurai class of feudal Japan. The tantō dates to the Heian period, when it was mainly used as a weapon but evolved in design over the years to become more ornate. Tantō were used in traditional martial arts (tantojutsu) and in the seppuku suicide ritual. The term has seen a resurgence in the West since the 1980s as referring to a point style of modern tactical knives, designed for piercing or stabbing, though the style is not present on any traditional tantō.
A Tanto knife may refer to an American style of blade based of the Japanese tantō, usually with a squared rather than curved tip.
The tantō is a single or double edged dagger with a length between 15 and 30 cm (6 and 12 in) (1 Japanese shaku). The tantō was designed primarily as a stabbing weapon, but the edge can be used for slashing as well. Tantō are generally forged in the hira-zukuri (平造) style (without a ridgeline), meaning that their sides have no ridge line and are nearly flat, unlike the shinogi-zukuri (鎬造) structure of a katana. Some tantō have particularly thick cross-sections for armor-piercing duty, and are called yoroi toshi.
Tantō were mostly carried by samurai; commoners did not generally wear them. Women sometimes carried a small tantō called a kaiken in their obi, primarily for self-defense. Tantō were sometimes worn as the shōtō (小刀) in place of a wakizashi in a daishō, especially on the battlefield. Before the advent of the wakizashi/tantō combination, it was common for a samurai to carry a tachi and a tantō as opposed to a katana and a wakizashi.
It has been noted that the tachi would be paired with a tantō and later the katana would be paired with another shorter katana. With the advent of the katana, the wakizashi was eventually chosen by samurai as the short sword of choice over the tantō. Kanzan Satō, in his book The Japanese Sword, notes that there did not seem to be any particular need for the wakizashi, and suggests that the wakizashi may have become more popular than the tantō due to the wakizashi being more suited for indoor fighting. He mentions the custom of leaving the katana at the door of a castle or palace when entering while continuing to wear the wakizashi inside.
The production of swords in Japan is divided into specific time periods:
The tantō was invented partway through the Heian period. With the beginning of the Kamakura period, tantō were forged to be more aesthetically pleasing, and hira and uchi-sori tantō became the most popular styles. Near the middle of the Kamakura period, more tantō artisans were seen, increasing the abundance of the weapon, and the kanmuri-otoshi style became prevalent in the cities of Kyoto and Yamato. Because of the style introduced by the tachi in the late Kamakura period, tantō began to be forged longer and wider. The introduction of the Hachiman faith became visible in the carvings in the hilts around this time. The hamon (line of temper) is similar to that of the tachi, except for the absence of choji-midare, which is nioi and utsuri. Gunomi-midare and suguha are found to have taken its place.
During the era of the Northern and Southern Courts, the tantō were forged to be up to 40 centimetres (16 in) in length, as opposed to the normal one shaku (about 30 cm (12 in)) length. The blades became thinner between the ura and the omote, and wider between the ha and mune. At this point in time, two styles of hamon were prevalent: the older style, which was subtle and artistic, and the newer, more popular style. With the beginning of the Muromachi period, constant fighting caused the mass production of blades, meaning that with higher demand, lower-quality blades were manufactured. Blades that were custom-forged still were of exceptional quality, but the average blade suffered greatly. As the end of the period neared, the average blade narrowed and the curvature shallowed.
Katana originate from sasuga (刺刀), a kind of tantō used by lower-ranking samurai who fought on foot in the Kamakura period. Their main weapon was a long naginata, with the sasuga as a spare weapon. In the Nanboku-chō period, which corresponds to the early Muromachi period, long weapons such as ōdachi were popular, and along with this, the sasuga lengthened, taking its form as the katana.
Approximately 250 years of peace accompanied the unification of Japan, in which there was little need for blades. In this period, both the katana and wakizashi were invented, taking the place of the tantō and tachi as the most-used pair of weapons, and the number of tantō forged was severely decreased. Since this period, tantō have often been carved with splendid decorations. Of the tantō and wakizashi forged during this period, three masterpieces are called the Nihon santō (Three Blades in Japan).
There were still a few tantō being forged during the late Edo period, and the ones that were forged reflected the work of the Kamakura, Nambokucho, or Muromachi eras. Suishinshi Masahide was a main contributor towards the forging of tantō during this age. There were now only tantō predating the Edo period being used in combat; tantō forged during the late Edo period were not combative weapons.
Many tantō were forged before World War II, due to the restoration of the Emperor to power. Members of the Imperial Court began wearing the set of tachi and tantō once more, and the number of tantō in existence increased dramatically. After World War II, a restriction on sword forging caused tantō manufacture to fall drastically.
Tantō remained in use among twentieth century yakuza (gangsters) since they could be carried as a concealed weapon more easily than a katana. A tantō is also traditionally used in the yubitsume ritual (cutting off part of a finger as an act of submission or atonement).
American and European interest in Japanese martial arts since the war created a demand for the tantō outside Japan from the 1960s through the present time.
A popular style of blade, known simply as a Tanto in the US and Europe, is similar in style to the Tantō except that the tip is squared at a shearing angle instead of curved.
The shearing angle may facilitate the stabbing effectiveness of the blade, and make the process of sharpening simpler.
This style of blade is commercially popular, and was used by CIA field agents in the wake of 9/11.
The Bundeswehr is among the few millitaries (if not the only) that issues a "tantō"-style military knife in significant numbers. It is designated as the KM2000.
Tantō with blunt wooden or blunt plastic blades are used to practice martial arts. Versions with a blunt metal blade are used in more advanced training and in demonstrations. Martial arts that employ the tantō include: