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),[1][5] 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.