Tachi
A is a type of sabre-like traditionally made Japanese sword (nihonto) worn by the samurai class of feudal Japan. Tachi and uchigatana generally differ in length, degree of curvature, and how they were worn when sheathed, the latter depending on the location of the 2=銘, or signature, on the tang. The tachi style of swords preceded the development of the katana, which was not mentioned by name until near the end of the twelfth century. Tachi were the mainstream Japanese swords of the Kotō period between 900 and 1596. Even after the Muromachi period, when katana became the mainstream, tachi were often worn by high-ranking samurai.
Features
With a few exceptions, katana and tachi can be distinguished from each other, if signed, by the location of the signature on the tang. In general, the signature should be carved into the side of the tang facing outward as the sword is worn on the wielder's left waist. Since a tachi was worn cutting edge down, and the katana was worn cutting edge up, the mei would be in opposite locations on the tang of both types of swords.An authentic tachi had an average cutting edge length of, and compared to a katana, was generally lighter in proportion to its length, had a greater taper from hilt to point, was more curved and had a smaller point area for penetrating heavy clothing.
Unlike the traditional manner of wearing the katana, the tachi was worn hung from the belt with the cutting edge down, and was most effective used by cavalry. Deviations from the average length of tachi have the prefixes ko- for "short" and ō- for "great, large" attached. For instance, tachi shōtō and closer in size to a wakizashi were called kodachi. The longest tachi in existence is in total length with a blade, but is believed to be ceremonial. In the late 1500s and early 1600s, many tachi blades were modified into katana, their cut tangs removing the smiths' signatures from the swords.
For a sword to be worn in tachi style, it needed to be mounted in a tachi koshirae. The tachi koshirae has two hangers so the sword can be worn in a horizontal position with the cutting edge down. A sword not mounted in a tachi koshirae could be worn tachi style by use of a koshiate, a leather device allowing any sword to be worn in the tachi style.