An uchigatana (打刀) is a type of Japanese sword used by the samurai class in feudal Japan. The uchigatana was the descendant of the tachi.
Uchigatana's Usage
Unlike the tachi, in which the acts of drawing and striking with the sword were two separate actions, drawing the uchigatana and cutting the enemy with it became a smooth and quick action.
This technique was developed in the arts of battojutsu, iaijutsu and iaido.
The curvature of the blade in uchigatana differs from tachi in that the blade has curvature near the tip of the sword (sakizori), as opposed to curvature near the hilt of the sword (koshizori) like tachi.
Because the sword is being drawn from below, the act of drawing has become the act of striking.
For a soldier on horseback, the sakizori curve of the uchigatana was essential in such a blade, as it allows the sword to come out of its sheath (saya) at the most convenient angle to execute an immediate cut.