Blue Tanto Laquered Case With Red Cord Clasp
The tantō is commonly referred to as a knife or dagger. The blade is single or double edged with a length between 15 and 30 cm. The tantō was designed primarily as a stabbing weapon, but the edge can be used for slashing as well.
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.
Some tantō have particularly thick cross-sections for armor-piercing duty, and are called yoroi toshi. Tantō were mostly carried by samurai, as commoners did not generally wear them.
It has been noted that the tachi would be paired with a tantō and later the uchigatana would be paired with another shorter uchigatana. With the advent of the katana, the wakizashi eventually was chosen by samurai as the short sword over the tantō.
Kanzan Satō in his book The Japanese sword notes that there did not seem to be any particular need for the wakizashi and suggests that the wakizashi may have become more popular than the tantō due to the wakizashi being more suited for indoor fighting. He mentions the custom of leaving the katana at the door of a castle or palace when entering while continuing to wear the wakizashi inside