Materials :Stainless Steels Series

  • Stainless Steels — Where Tradition Meets Modern Convenience

    Stainless steels changed the destiny of knives. Once seen as a compromise against the sharpness of carbon steel, they have evolved into some of the most advanced materials in Japanese knife-making. By introducing chromium and carefully balancing alloying elements, Japanese stainless steels protect against rust while still offering razor-like edges that rival their carbon counterparts.

    In this series, we explore steels that bridge eras and philosophies. From the semi-stainless “Super Steel” developed with vacuum heat treatment and sub-zero processing, to Ginsan (Silver #3), the stainless that feels like carbon, to ZDP189, the pinnacle of powdered metallurgy—each represents a dialogue between centuries of tradition and the cutting-edge science of metallurgy.

    These steels are not just convenient. They are transformative. By reducing the burden of maintenance, they allow chefs to devote more energy to their craft while still enjoying the tactile satisfaction of authentic Japanese edges. For today’s culinary world—where precision, efficiency, and reliability are demanded daily—stainless steels stand as proof that Japanese knife-making is not bound by the past but constantly reshaped by innovation.

Super Steel: The Future of Japanese Knives

  • Tradition refined by innovation, trusted by chefs worldwide.

    Super Steel represents the future of Japanese knife-making—a material where centuries of tradition meet the science of advanced metallurgy.

    Developed as a semi-stainless steel enriched with molybdenum, chromium, and tungsten, Super Steel combines razor-sharp performance, remarkable durability, and corrosion resistance in one blade. Its secret lies in cutting-edge treatments: vacuum heat treatment ensures uniform hardness without oxidation, while sub-zero processing refines the structure for long-lasting edge retention. The result is a guaranteed HRC62 ±1—hard enough for precision, yet stable enough for everyday reliability.

    For chefs, Super Steel offers the best of both worlds: corrosion resistance for hygiene, sharpness that rivals carbon steels, and a tactile responsiveness that feels natural in hand. Unlike ultra-hard alloys such as ZDP-189, it balances strength with sharpenability, making it practical for both professionals and serious home cooks.

    More than a material, Super Steel is a bridge between past and future—a blade that carries the soul of swordsmiths into the kitchens of tomorrow.
Super Steel

ZDP189: Where Tradition Meets Innovation

  • A stainless steel that redefines sharpness and endurance.

    ZDP189 is not just another stainless steel—it is a revolution in Japanese knife-making. Developed by Hitachi Metals through advanced powder metallurgy, ZDP189 pushes the boundaries of what steel can achieve. With hardness levels reaching 66–68 HRC, it belongs among the hardest and most durable steels ever used in fine cutlery.

    What makes ZDP189 extraordinary is its ability to combine extreme hardness with outstanding wear resistance. Once properly sharpened, a ZDP189 blade holds its edge far longer than conventional steels, making it an invaluable ally in professional kitchens where long prep hours and consistency are essential. At the same time, its stainless-based composition ensures far greater rust resistance than carbon steel, easing the burden of maintenance.

    However, this performance comes with demands. ZDP189 is a challenging steel to sharpen, requiring skill, patience, and the right tools. It is not forgiving, but for those who embrace its discipline, the rewards are immense—an edge that endures, precision that inspires, and a knife that feels as if it belongs to the future.

    For chefs seeking uncompromising performance and culinary expression, ZDP189 represents the frontier of knife-making: a blade that bridges tradition and innovation, expanding both the possibilities of the kitchen and the skill of the one who wields it.
ZDP189

Ginsan: The Stainless Steel That Honors Tradition and Empowers Today’s Chefs

  • Sharpness like carbon steel, with the durability of stainless.

    The soul of a Japanese knife lies in its steel—and few materials express that spirit as clearly as Ginsan. Known also as Silver #3, Ginsan has been cherished for decades in the world of traditional Japanese blades. It stands as a bridge between past and present, combining the razor-like sharpness of carbon steel with the rust resistance modern kitchens demand.

    What makes Ginsan exceptional is its harmony of opposites. It sharpens with the smooth, responsive feel of carbon steel, yet resists corrosion like stainless. This balance is not a product of machines, but of artisans who hammer, stretch, and shape the steel by hand—transforming each blade into a work of living craftsmanship. The result is a knife that delivers not only precision and resilience, but also a tactile joy that grows richer with every use.

    Ginsan knives are an investment in skill and tradition. They cost more than mass-produced alternatives, but the price reflects the artistry, materials, and commitment behind every blade. For chefs who see knives not only as tools but as partners in creation, Ginsan offers unmatched sharpness, ease of care, and enduring beauty.

    Whether you are a professional chef seeking balance in a demanding kitchen, or a passionate home cook aspiring to experience authentic Japanese steel, Ginsan invites you into a tradition that is still evolving. With each cut, it reveals not only the flavor of your ingredients but also the pride of the hands that forged it.

    Ginsan is more than stainless—it is tradition refined, empowering chefs today, and carrying Japanese knife-making into the future.
Ginsan

Why Ginsan Is So Difficult to Forge: The Challenge Behind Stainless Sharpness

  • A stainless steel as demanding as carbon, mastered by only a few.

    Ginsan is admired for achieving the impossible: the sharpness and whetstone feel of carbon steel, combined with the rust resistance of stainless. But behind this harmony lies one of the most demanding challenges in Japanese bladesmithing.

    Unlike typical stainless steels, Ginsan has a carbon content approaching that of high-carbon steels. This gives it both sharpness and hardness—but also makes it extremely difficult to forge. Every step demands absolute precision. A few degrees too hot or too cool, and the steel loses its edge potential. Its toughness makes shaping labor-intensive, and only a handful of smiths in Japan have the skill and patience to bring out its true character.

    At KIREAJI, many of our Ginsan blades are forged by Shougo Yamatsuka of the Shiroyama Knife Workshop. Known for his refined control and dedication, Yamatsuka-san crafts Ginsan knives that embody balance, resilience, and subtle yet enduring sharpness. His work transforms this challenging material into blades that chefs trust as lifelong partners.

    For those who hold a Ginsan knife, it is more than just steel—it is the continuation of 600 years of Sakai tradition, elevated through relentless innovation. Each slice is not only a test of the steel, but also an expression of the craftsman’s spirit, turning everyday cooking into an art form.
Why Ginsan Is So Difficult to Forge

Ginsan (Honyaki): Stainless Purity, Traditional Discipline

  • A stainless Honyaki that blends tradition with modern practicality.

    Ginsan, also known as Silver-3, is a stainless tool steel forged with about 13–14.5% chromium and around 1% carbon. Designed to resist rust while maintaining the responsive, carbon-steel-like edge that chefs love, Ginsan represents the rare balance of tradition and practicality.

    In Honyaki construction—where a knife is forged from a single piece of steel and hardened by traditional heat treatment—Ginsan takes on new meaning. Unlike laminated blades, Honyaki knives demand precision and mastery, and in Sakai they are regarded as pinnacle builds, produced only by select specialists.

    Why do many smiths choose air quenching for Ginsan? The answer lies in stability. Air cooling after heat treatment reduces the risk of cracking and warpage, which is critical when working with mono-steel blades where correction is nearly impossible. This method allows smiths to bring out the steel’s full potential with consistency and confidence.

    The result is a knife that feels clean and controlled in use. It glides through fish, vegetables, and meats with precision, maintains its edge over long prep sessions, and avoids the harshness often associated with high-carbide stainless steels. On the whetstone, Ginsan responds predictably and efficiently, rewarding chefs with a sharpening experience that is satisfying without being punishing.

    For professionals who value mono-steel tradition but want the convenience of stainless, Ginsan Honyaki is an ideal partner. It offers classic feedback, reliable performance, and resilience in the fast pace of daily service.

    Ginsan Honyaki—stainless purity guided by traditional discipline, crafted to serve those who see cooking not only as work but as a lifelong pursuit of refinement.
Ginsan (Honyaki)

Why Ginsan Honyaki Uses Air Quenching : A Decision Forged in Science and Tradition

  • Air quenching: the balance of science and craftsmanship in stainless Honyaki.

    A great knife is more than sharpness—it is the sum of every decision made in its creation. For Ginsan Honyaki, one of the most crucial choices occurs during heat treatment: the use of air quenching.

    In quenching, the blade is heated to high temperatures and then cooled to form martensite, the fine structure that gives it hardness, durability, and edge life. Yet this transformation is a delicate balance. If cooled too quickly, the blade may crack. If cooled too slowly, it may never achieve full hardness. Precision is everything.

    Ginsan, with its high chromium content, offers exceptional hardenability, which allows it to fully transform even under slower cooling. This makes air quenching an ideal choice. Unlike water or oil, air cooling reduces the risks of cracking and warpage, ensures even transformation across the blade, and produces a refined, resilient structure. In Honyaki construction—where a knife is forged from a single piece of steel and every detail is final—this control is essential.

    The result is a blade that feels clean and confident in use, gliding through ingredients with clarity while maintaining reliable sharpness throughout long hours of prep. On the whetstone, Ginsan responds smoothly and predictably, allowing chefs to refine the edge with consistency and without excessive effort.

    For stainless Honyaki, air quenching is not a matter of convenience but a decision born from the union of material science and Japanese tradition. It is the quiet mastery behind a blade that is hard, resilient, and built to serve chefs for decades, carrying precision and discipline into every cut.
Why Ginsan Honyaki Uses Air Quenching

  • Epilogue: Stainless as the Spirit of Modern Craft

    To call stainless steels “convenient” is to miss their deeper meaning. They are not only a safeguard against rust—they are the expression of how Japanese craftsmanship adapts, evolves, and endures.

    From the balanced elegance of Ginsan to the futuristic hardness of ZDP189, from the refined discipline of stainless Honyaki to the innovative treatments of Super Steel, each alloy carries a story. That story is about resilience: how tradition can survive, not by resisting change, but by embracing it with mastery.

    When you choose a stainless Japanese knife, you are choosing more than durability. You are choosing to carry forward the spirit of centuries-old forging into a world that demands speed, hygiene, and reliability. In every slice, stainless steels remind us that progress and tradition are not enemies—they are partners, cutting side by side into the future.

Knowledge Quiz: Stainless Steels Series

Origins & History

From samurai swords to modern kitchens, discover how Japanese knives became cultural icons of sharpness, tradition, and identity.

Origins & History

Regions & Craftsmen

Explore Sakai, Sanjō, and Seki—the three great knife-making centers of Japan. And in Sakai, meet the master artisans whose hands preserve tradition and shape the future of Japanese blades.

Regions & Craftsmen

Structure & Features

Uncover the secrets of single-bevel geometry, urasuki hollows, and design features that make Japanese knives precise and unique.

Structure & Features

Crafting Process

Follow the journey from raw steel to living blade—through forging, quenching, sharpening, and finishing guided by master hands.

Crafting Process

Types of Knives

From Yanagiba to Deba to Usuba, learn why Japan developed so many specialized blades and how each reflects culinary culture.

Types of Knives

Blade Finishes

From the precision of Honbazuke sharpening to the elegance of mirror polish, the flowing patterns of Damascus, and the subtle refinement of kido finishing—each finish tells its own story of craftsmanship.

Blade Finishes

Usage & Care

Learn the daily practices—washing, drying, storing, sharpening—that preserve a knife’s sharpness, beauty, and spirit for decades.

Usage & Care

Mindset & Philosophy

Discover The Chef’s Code—principles of character, skill, knowledge, devotion, and professionalism that connect chef and knife

Mindset & Philosophy