Shinken (真剣, しんけん) refers to a sharp, "genuine" Japanese sword, katana, of which there are many types such as tachi, wakizashi, tantō, ōdachi, nagamaki, and naginata. The term is used in contrast to training tools such as bokken and shinai.
A shinken is made according to traditional methods and primarily attracts collectors, but is also used by higher ranks in, among other things, the budo sport of iaido.
The sword is sharp and is used in tameshigiri training and should be handled with caution and knowledge. An iaitō or mogitō is a blunt, simpler sword for iaido exercises, which is less demanding on the practitioner than a real shinken.
"Gendaitō" are hand-forged shinken that are still produced by around 200 active Japanese swordsmiths, who are members of the Japanese Swordsmith Association.
Their annual production is limited by Japanese law. This, along with the requirement for highly specialized skills and the majority being manual labor, contributes to the high prices commanded by a Japanese-made shinken (Nihontō).
Therefore, there is also a large market for cheaper "shinken" manufactured outside Japan - primarily in China. These are rejected by collectors, but are easier to obtain and are sufficient for budo exercises, for which one does not want to risk damage to a more valuable sword.
Tameshigiri
Tameshigiri (試し斬り, 試し切り, 試斬, 試切) is the Japanese art of test-cutting an object. The phenomenon gained popularity during the Edo period to test the quality of Japanese swords and is still practiced today.
Formal quality testing could previously only be performed by the most skilled swordsmen so that their ability would not be a factor affecting the sword's suitability.
The materials used varied, but rice straw, wara, the top layer of tatami mats (goza), or bamboo were common. Executions could also be performed as tameshigiri.