Gold Super A type of Yasuki steel produced in Yasugi City, Shimane Prefecture. The official name is Kin-gami-kou (金紙鋼), and within that, there is a grade called "Gold Super." Features Extremely high hardness (around HRC 64) Very sharp cutting edge Excellent wear resistance (good edge retention) Mainly used in high-end Japanese knives and knives for hobbyists. Positioning of "Kin-gami (Gold Super)" in Knives Often classified as a top-grade steel, alongside Aogami Super. Hardness (HRC) Often reaches around HRC 64 after quenching. → Equivalent to or even higher than Aogami Super. → Therefore, the cutting edge is sharp and long-lasting. Especially when craftsmen finish them using traditional techniques such as "hizo sumi-uchi" (secret charcoal forging) and "tanzo" (forging), they develop beautiful hammered patterns and flowing water patterns, increasing their collectibility. What is "Sumi-uchi"? It's an abbreviation of "tanbi tanzo" (炭火鍛造), which means charcoal fire forging. It is a traditional technique where steel is heated using charcoal fire as a heat source and forged by a craftsman hammering it. It has been used since ancient times in the manufacturing of Japanese swords and Japanese knives, and requires the skill of experienced craftsmen because temperature control is more difficult compared to modern gas furnaces and electric furnaces. Features of Sumi-uchi The steel structure becomes finer. Impurities are removed by hammering, and the blade's toughness (flexibility) and hardness are well-balanced because it is slowly quenched in charcoal fire. Unique patterns (flowing water and hammered patterns) are created. When forged in layers, beautiful wave patterns called "unuki" or "flowing water" appear. This is also a charm of charcoal fire forging. Each piece has a different appearance. Because it is hand-forged, the finish differs even with the same steel material, making it a one-of-a-kind knife in the world. What does "Hizo" mean? "Hizo" (秘蔵) is an expression that conveys the meaning of being particularly particular, made by skilled craftsmen, and rare. In other words, "Hizo Sumi-uchi" is a term that represents: A special knife carefully finished by a craftsman using traditional charcoal fire forging. -------Search Terms-------- Gyuto (Chef's Knife) Wa-gyuto (Japanese Chef's Knife) Petty Knife Santoku Sujihiki (Slicer) Garasuki (Butcher Knife) Honesuki (Boning Knife) Slicer Yanagiba (Sashimi Knife) Deba Bocho (Deba Knife) Usuba Bocho (Vegetable Knife) Sashimi Bocho (Sashimi Knife) Yo-bocho (Western-style Knife) Wa-bocho (Japanese-style Knife) Sakai Ichimonji Sakai Takayuki Masamoto Sugimoto Aritsugu Konohi Kouhou Kiya Tojiro Yusuke Gin-san Bocho (Silver #3 Steel Knife) Misono Glestain Henckels Jikko