Tanto (17.7inch)

Tantō (たんとう): The tantō is a dagger. The blade is single or double edged with a length between 15 and 30 cm (6–12 inches, in Japanese 1 shaku).  Tantō are generally forged in hira-zukuri style (without ridgeline), meaning that their sides have no ridge line and are nearly flat, unlike the shinogi-zukuri structure of a katana. With the beginning of the Kamakura period, tantō were forged to be more aesthetically pleasing, and hira and uchi-sori tantō becoming the most popular styles.