A Japanese sword (日本刀 nihontō?) is one of several types of traditionally made swords from Japan. Swords have been made from Kofun period and generally Japanese swords are the ones after the Heian period having curves, and there are many types of Japanese swords that differ by size, shape, field of application and method of manufacture. Some of the more commonly known types of Japanese swords are the katana, wakizashi, and tachi.
The type classifications for Japanese swords indicate the combination of a blade and its mounts as this, then, determines the style of use of the blade. An unsigned and shortened blade that was once made and intended for use as a tachi may be alternately mounted in tachi koshirae and katana koshirae. It is properly distinguished, then, by the style of mount it currently inhabits. A long tanto may be classified as a wakizashi due to its length being over 30 cm, however it may have originally been mounted and used as a tanto making the length distinction somewhat arbitrary but necessary when referring to unmounted short blades. When the mounts are taken out of the equation, a tanto and wakizashi will be determined by length under or over 30 cm unless their intended use can be absolutely determined or the speaker is rendering an opinion on the intended use of the blade. In this way, a blade formally attributed as a wakizashi due to length may be informally discussed between individuals as a tanto because the blade was made during an age where tanto were popular and the wakizashi as a companion sword to katana did not yet exist.
The following are types of Japanese swords:
It should be noted that there are bladed weapons made in the same traditional manner as other Japanese swords and they are also considered to be swords even though they are not swords, these include:
Arrowheads for war, yajiri, were also made using the same methods as Japanese swords were.
The production of swords in Japan is divided into time periods:
In modern times the most commonly known type of Japanese sword is the Shinogi-Zukuri katana, which is a single-edged and usually curved longsword traditionally worn by samurai from the 15th century onwards. Other types of Japanese swords include: tsurugi or , which is a double-edged sword;ōdachi, tachi, which are older styles of a very long single-edged sword; wakizashi, a medium-sized sword and tantō which is an even smaller knife-sized sword. Naginata and yari despite being polearms are still considered to be swords.