The Iaito is a contemporary practice sword made of metal and does not have a cutting edge which is why it is primarily utilized for practicing the art of Iaido. A real and authentic katana with a sharpened cutting edge is called a shinken and in contrast to this sword, the Iaito features no cutting edge and is not recommended for sword to sword use.
Although the Iaito is a sword mainly used for practice, it should not be confused with faux swords that are available since these are generally made for decorative purposes and are unsafe for practicing martial arts.
Most of the Iaito swords are made out of an aluminum-zinc alloy which is definitely lighter and cheaper compared to high-quality and authentic steel; also, making use of a blunt edge and alloy avoids the legal restrictions of the Japanese when it comes to manufacturing swords made out of ferrous components or metals.
Because of this, the Japanese-forged Iaito are primarily made for practice and exercises thus, are not recommended for any form of contact. You will know which ones are the best reproductions of the real authentic swords since these replicas have exactly the same shape and weight along with its mirrored high-quality fittings and finish; the iaito may even have a special blade pattern that is the temper line of a finely tempered steel blade (hamon).
The regular weight of an authentic uchigatana is around 1,200 grams without its scabbard, while the iaito measures roughly around 820 grams; there are a few steel iaito created as well but these only weigh around 900 to 960 grams despite it having a 74 centimeter sized blade.
If you are someone who wishes to have something that is a bit more traditional and authentic, you can find an iaito that has been created from folded steel which is generally like the real Japanese katana but instead of a sharp cutting edge, it features a blunt edge which is best for practice.
Although these weapons feature such types of edges, the swords would still face the same ownership and usage restrictions in Japan just like with the authentic samurai swords and would not be called the iaito.
The First Iaito
The company Meirin Sangyo claims to be the very first group to create an iaito; yet in history, the very first iaito were created right after World War II to allow people who do not have any means to actually own an authentic sword, own a weapon that they can utilize to practice modern budo.
There are a couple of dojos in Japan that only recommend the use of alloy blades during the practice of iaido until the skills of the individual practicing the art is consistent enough to utilize a real sharp-edged weapon; however, there are a few schools that allow their practitioners to make use of a sharp-edged sword right away while others completely prohibit the use of this.
The katana is obviously one of the most common and favored weapons in Japan, popular culture, and most especially in the world of martial arts; however, the iaito is also quite a known name in popular culture since the weapon has been used for a variety of things: a character from a fighting game called Soul Calibur III wields an iaito blade that is concealed in a parasol made of oil paper; in another video game called Dark Souls, the iaito is one of the available weapons of choice that the character may use to successfully win the game.