Hiromoto Utility Knife 150mm Hiromoto Knives: Hiromoto has been producing professional quality knives for decades in Seki City, Japan. The knives that we carry are the Aogami Super line and are forged from carbon steel, an ultimate Hagane refined from Yasugi sand-irons. These knives are made of high Carbon steel (1.40 - 1.50) with Chromium (0.30 – 0.50) and Tungsten (2.00 – 2.50) added for edge retention and durability. They hardness of the steel measures Rockwell 60-62. The blades are clad with 405 stainless steel to protect from rusting except the cutting edge. The result is an easy to sharpen knife that is durable and perfectly balanced and can hold a razor sharp edge.