• Yasuki Steel: A Supreme Blend of Japanese Tradition and Innovation

  • Have you ever struggled with a dull kitchen knife while cooking? The sharpness of a knife not only affects the quality of your dishes but also influences the joy of cooking itself. Discovering the world-renowned Sakai Knives and the exceptional material behind their performance, Yasuki Steel, unveils the essence of Japanese craftsmanship.

  • Yasuki Steel: The Soul of Japanese Craftsmanship

    Yasuki Steel, produced by Hitachi Metals at its Yasugi Works in Shimane Prefecture, is a high-quality steel brand with roots tracing back to the Meiji Era. Its heritage is deeply connected to "Tatara Ironmaking," a traditional method using high-purity sand iron, which has been supporting Japan's blade culture since ancient times.

  • Yasuki Steel is available in different series, including White Steel, Blue Steel, and Yellow Steel, each with unique characteristics. For example, White Steel offers high hardness, making it ideal for precision knives, while Blue Steel, enriched with tungsten, provides enhanced durability and is commonly used for premium blades. This versatility has made Yasuki Steel a trusted choice among blade artisans worldwide.

  • Sakai Knives: A Masterpiece of Tradition and Craft

    Hailing from Sakai City, Osaka, Sakai Knives represent Japan’s rich blade-making history, dating back over 600 years. The unparalleled quality of Sakai Knives owes much to the use of Yasuki Steel, which blends seamlessly with the craftsmanship of Sakai’s artisans to produce knives with unmatched sharpness and durability.

  • The production process of Sakai Knives sets them apart from mass-produced alternatives. Artisans meticulously handle every step, from forging to heat treatment and final sharpening, transforming Yasuki Steel into extraordinary blades. This meticulous process extracts the steel’s fullest potential, resulting in knives that epitomize precision and beauty.

  • The Global Recognition of Yasuki Steel and Sakai Knives

    Sakai Knives made with Yasuki Steel are cherished by chefs and culinary enthusiasts worldwide. These knives transcend their role as tools, embodying the fusion of masterful craftsmanship and premium materials. Every slice becomes an experience of tradition and innovation.

  • A Michelin-starred chef shared this sentiment:

    "Sakai Knives are not just tools. They are instruments that breathe life into culinary creations and symbolize the spirit of Japanese craftsmanship."

    This acclaim underscores the synergy between Yasuki Steel's outstanding properties and the skill of Sakai’s artisans.

  • Preserving Tradition While Shaping the Future

    The relationship between Yasuki Steel and Sakai Knives extends beyond the realms of material and product. It exemplifies a harmonious partnership where Japanese tradition and innovation continuously inspire new value. Through this partnership, Japanese craftsmanship evolves toward the future.

  • Owning a Sakai Knife means more than acquiring a tool—it means holding a piece of Japan’s culture, history, and the passion of its artisans. Whether you are a professional chef, a cooking enthusiast, or someone curious about Japanese tradition, we hope you experience the allure of Sakai Knives firsthand.

  • Types of Yasuki Steel

  • 1. White Steel (Shirogami)

    White Steel is composed primarily of iron (Fe) and carbon (C). Its performance varies significantly with carbon content, leading to classifications such as White Steel #1, #2, and #3. Even a 0.1% change in carbon content can dramatically alter the metal's hardness and workability, making it an exceptionally delicate material.

  • White Steel #1, with the highest carbon content, offers superior hardness and wear resistance. Blacksmiths purchase this steel from Hitachi Metals (now Proterial) to either add to base metals or use directly in high-end knives.

  • 2. Blue Steel (Aogami)

    Blue Steel is widely recognized as a traditional high-end knife material in Japan. It's created by adding chromium and tungsten to white paper steel. Key characteristics include:

    • High hardness and excellent sharpness
    • High wear resistance and toughness, resulting in long-lasting sharpness

  • 3. Ginsan

    Ginsan is a type of stainless steel and a relatively new knife material. It's a high-carbon stainless steel that combines the high sharpness of Blue Steel with the rust-resistance of stainless steel.

    Ginsan offers good sharpness and durability. While not as sharp as Blue Steel, it's easier to maintain, rust-resistant, and suitable for daily use.

  • These steel materials are further classified into No. 1, No. 2, and No. 3 based on their carbon (C) content. For example, Blue Steel and White Steel contain 1.00-1.40% carbon.

  • The Appeal of Yasuki Steel: Artworks Born from Craftsmen's Skills

    The appeal of Yasuki Steel lies not only in its performance. Each Yasuki Steel knife, meticulously finished by skilled bladesmiths, is truly a work of art. The beauty of the blade pattern, the texture of the handle, and the perfect balance when held in hand—all these elements multiply the joy of cooking.

  • Yasuki Steel is particularly favored by knife craftsmen in Sakai. Its superior quality and ease of handling support the tradition of Sakai forged blades, which represent Japan.

  • The Future of Yasuki Steel: A Brilliant Tradition and an Uncertain Outlook

    However, the future of this wonderful Yasuki Steel is now in crisis. Recent developments have cast a dark shadow over the future of this precious steel.

  • 1. Uncertainty due to business transfer:
    In 2023, Hitachi Metals, which had been manufacturing Yasuki Steel for many years, was sold to Bain Capital, a U.S. investment fund. As a result, the Yasuki Steel manufacturing business was transferred to a new company called "Proterial" and is now operated under foreign capital. This change has placed the manufacture of Yasuki Steel, a traditional Japanese technology, at the mercy of foreign companies focused on profits.

  • 2. Market size issues:
    High-grade cutting steel     like Yasuki Steel accounts for only a small portion of the overall metal market. Therefore, large steel companies are questioning the profitability of continuing its production.

  • 3. Changes in corporate policy:
    In 2021, Hitachi Ltd. decided to sell Hitachi Metals to Bain Capital due to the unprofitability of its special steel division. This decision shows how the special steel division, including Yasuki Steel, was viewed as an unprofitable sector within large corporations.

  • These factors combined have raised significant questions about the continuity of Yasuki Steel production. The day may come when this wonderful traditional Japanese technology, which we have taken for granted, becomes unavailable.

  • What We Can Do: Preserving Tradition and Sparking Innovation

  • So, what can we do? We can understand the value of Yasuki Steel and share its excellence with many people. By using Yasuki Steel knives, experiencing their charm, and passing this on to the next generation, we can protect and further develop this proud Japanese traditional technology.

  • Why not try a Yasuki Steel knife? It will surely bring new brilliance to your cooking life and your heart. And by sharing its excellence with those around you, we can make the future of this precious technology a little brighter.

  • Yasuki Steel, the ultimate knife material that embodies the soul of Japan. Experience its excellence and join in considering its future. Now is the time for us to take action.
Material of Knife

FAQ About Yasuki Steel

What is Hitachi Yasuki Steel?

Yasuki steel is a brand of steel produced at the Yasuki plant of Hitachi Metals, Ltd., located in Shimane Prefecture. Since ancient times, the region has been renowned for producing steel using the "Tatara" smelting method, and the steel made in the area was shipped from the port in Yasuki. Today, the Yasuki plant continues this tradition, manufacturing Yasuki steel.

Why is Hitachi Metals being sold?

Here’s the English version after proofreading:

What is Hitachi Yasuki Steel?
Yasuki steel is a brand of steel produced at the Yasuki plant of Hitachi Metals, Ltd., located in Shimane Prefecture. Since ancient times, the region has been renowned for producing steel using the "Tatara" smelting method, and the steel made in the area was shipped from the port in Yasuki. Today, the Yasuki plant continues this tradition, manufacturing Yasuki steel.

Why is Hitachi Metals being sold?
Hitachi, Ltd. is selling its key subsidiary as part of a strategy to focus on its core businesses, such as IT-based enterprise services. It seems that, in the process of pursuing "selection and concentration," Hitachi Metals, a materials manufacturer, was seen as generating less synergy with these core areas. Hitachi has historically expanded its group through spin-offs and the public listing of its subsidiaries, and this sale is seen as part of that broader strategy.

What makes Tamahagane (traditional Japanese steel) so special?

Tamahagane contains non-metallic inclusions (such as oxides and sulfides) that are very soft and easily stretched. Through repeated folding and forging, these characteristics enhance the toughness of Japanese swords, create beautiful patterns on the surface, and improve the ease of sharpening. For these reasons, Tamahagane is an ideal material for making Japanese swords.

What are the raw materials of Yasuki steel?

Blue paper steel (Aogami) is made from the same 100% sand iron-based raw material as white paper steel (Shirogami), with an addition of 0.4% chromium (Cr) and 1.8% tungsten (W). This composition increases its toughness and hardening properties during quenching. Due to the differences in raw materials and manufacturing processes, blue paper steel is considerably more expensive than white paper steel.

The Origin of Craftsmanship

  • The Brilliance of Japanese Knives, Powered by Hitachi Metals' Technology

    The beauty and sharpness of Japanese knives transcend mere tools—they are truly worthy of being called works of art. However, did you know that their excellence is rooted in the power of materials? One of the key reasons Japanese knives are highly acclaimed worldwide is the presence of high-quality steel produced by Hitachi Metals.

  • The steel we artisans use is refined to an extraordinary degree, with impurities minimized to create a material that is both uniformly strong and incredibly flexible. This superior material is the secret behind Japanese knives' ability to be thin yet astonishingly durable. Because the steel is exceptional, we craftsmen can confidently forge and sharpen the blade to perfection.

  • The harmony of Hitachi Metals' advanced technology and traditional craftsmanship creates Japanese knives that are more than just tools for cutting. They support culinary culture and bring inspiration to chefs and households alike. It is through this fusion of Japan's tradition and cutting-edge innovation that we produce valuable works of craftsmanship to pass on to future generations.
Sakai Traditional Craftsmen Collection

  • Be Cautious with Inexpensive Knives

  • Buying a cheap knife may mean that the steel used is of low quality. Low-quality steel tends to lose its sharpness quickly, which can ultimately reduce the efficiency of your cooking tasks.

    At KIREAJI, we provide authentic Japanese knives crafted by trusted craftsmen from knife-making workshops in Sakai City. Each knife is handcrafted with care, ensuring you receive a reliable and high-quality product that brings peace of mind.