blue steel
Blue steel #1 (Aogami #1, Ao-ichi ko)
(1.35% Carbon (C), 0.5% Chromium (Cr), 0.3% Manganese (Mn), 0.2% Silicon (Si), 2% Tungsten (W)) High quality carbon steel, used in high end knives, especially kitchen knives. Despite its hardness, it has a decent sharpness and high durability, fineness and durability of the blade. The toughness is slightly lower than that of Blue steel #2. A very good sharpening steel, with easy maintenance of the blade, e.g. dressing leather . Typical Rockwell hardness up to 65HRc. Japan / Hitachi (Yasugi)
Blue steel #2 (Aogami#2, Ao-ni ko)
(1.15% Carbon (C), 0.5% Chromium (Cr), 0.3% Manganese (Mn), 0.2% Silicon (Si), 1.5% Tungsten (W)) Very pure and high quality steel, with high hardness and the possibility of very fine edge. Used on kitchen knives. Very maintainable blade, for example, only for dressing leather. Typical Rockwell hardness up to 63HRc. Japan / Hitachi (Yasugi)