Yoshihiro Hayate ZDP-189 Super High Carbon Stainless Steel Sujihiki Kiritsuke Knife Octagonal Triple Ring Ebony Handle with Water Buffalo Horn Bolster

Yoshihiro Hayate ZDP-189 Super High Carbon Stainless Steel Sujihiki Kiritsuke Knife Octagonal Triple Ring Ebony Handle with Water Buffalo Horn BolsterZDP 189 is a premium powdered metallurgy steel developed by Hitachi and is widely regarded as one of the hardest steels used in high end Japanese cutlery, even exceeding the hardness of HAP40. Hardened to approximately 6567 HRC, it delivers exceptional edge retention and the ability to hold an extremely fine cutting edge for an extended period, which is why it has become one of the most sought after steels among professionals and serious enthusiasts.

ZDP-189 is a premium powdered metallurgy steel developed by Hitachi and is widely regarded as one of the hardest steels used in high-end Japanese cutlery, even exceeding the hardness of HAP40. Hardened to approximately 65–67 HRC, it delivers exceptional edge retention and the ability to hold an extremely fine cutting edge for an extended period, which is why it has become one of the most sought-after steels among professionals and serious enthusiasts.

With its very high carbon and chromium content, ZDP-189 combines extreme hardness with good corrosion resistance, allowing the edge to last far longer than most conventional kitchen knife steels. This level of performance greatly reduces the need for frequent sharpening, though the same hardness means ZDP-189 requires more skill and proper equipment if sharpening or edge repair is needed.

Due to its cost and demanding production process, ZDP-189 is typically reserved for top-tier knives and is most often used as a hardened core in laminated (San Mai) constructions. Cladding the core with softer stainless steel adds toughness and ease of maintenance while preserving the outstanding cutting performance and edge retention that define ZDP-189.