A chokutō is a type of straight sword that was used in ancient Japan prior to the development of the curved katana. The chokutō is characterized by its straight blade and lack of curvature. The length of a chokutō can vary, but generally, they were around 60 to 80 centimeters (approximately 23 to 31 inches) in blade length.

It's worth noting that the term "chokutō" is a broad classification for straight swords and can encompass various designs and lengths throughout different historical periods. The chokutō was eventually succeeded by the tachi and later the katana, both of which had curved blades and became more prevalent in Japanese swordsmithing.

The chokutō had its origins in China and was introduced to Japan during the Yayoi period (300 BCE to 300 CE). Over time, Japanese swordsmiths developed their own unique sword styles, culminating in the iconic curved katana that is closely associated with samurai culture.