Aogami Super Blue steel is produced exclusively by Hitachi Metals for tools and knives. In Hitachi's plant in the Shimane Prefecture, Japan, they use high quality iron-sand found only in this region. Shimane Prefecture sand has been used and preferred for making Japanese cutlery since ancient times. Hitachi creates and offers different grades of steels including white steels and blue steels. The steel isn't blue or white but the designation refers to the color of the paper the raw steel is wrapped in when delivered to Hitachi. It is common practice for Japanese steels to be named and referred to; based on what colored packaging the raw steel arrives to the maker. Super Blue is the highest grade blue steel and contains up to 1-1/2% carbon for wear resistance and chrome to elevate hardness and improve edge holding and corrosion resistance. Steel smiths agree Super Blue is easier to heat-treat and work with than some steels but is more wear resistant and harder to hand grind. Classified as exotic steel by cutlery standards, it has a loyal following with custom kitchen knifemakers looking for superior cutting performance for cutting materials that are soft and sticky to rock hard or fibrous.