胁差（わきざし，Wakizashi is also called 胁指. The wakizashi has a blade between 30 and 60 cm. The tantō is a dagger. The blade is single or double edged with a length between 15 and 30 cm (6–12 inches). 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.