Japanese suminagashi steel blade blanks to forge and shape into daggers and utility knives. This 8 layer Suminagashi steel is usually forged onto both sides of a hard core layer (blue or white paper steel). Each of these 8 layers of steel consists in turn of a “Gokunan-Koh” layer (traditional soft steel) that is welded to a thin, alloyed carbon steel layer, which prevents the steel from decarbonizing too quickly.