• Yasuki Steel: The Ultimate Knife Material Embodying Japan's Soul - A Fusion of Tradition and Innovation

  • Have you ever felt dissatisfied with the sharpness of your kitchen knife while cooking? A dull knife not only reduces the quality of your cooking but also increases preparation time. The solution to this problem, which can multiply the joy of cooking, is "Yasuki Steel," a product that Japan proudly presents to the world.

  • What is Yasuki Steel? The Crystallization of Japanese Ironmaking Technology Dating Back to Ancient Times

    Yasuki Steel (Yasuki Hagane) is the brand name for high-grade steel manufactured at the Hitachi Metals Yasugi Works in Yasugi City, Shimane Prefecture. Its history dates back to ancient times. Shimane Prefecture has long been known for its steel production using the tatara ironmaking method, and Yasugi City prospered as a shipping port for this steel.

  • Today, the Yasugi Works combines this traditional ironmaking technology with cutting-edge techniques to produce high-quality steel under the brand name "YSS Yasuki Hagane." This steel is primarily used for knives and other cutting tools and is beloved by chefs worldwide for its exceptional quality.

  • 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

  • Don’t focus on numbers. The most important information when striking is the color of the steel.

  • I often get asked, “What temperature should I heat it to?” But, in reality, you don’t need to look at a thermometer. What matters most is the color of the steel right in front of you.

  • With experience, just looking at the color will tell you what state the steel is in. A bright orange is just about the right color. It’s an instinct developed from years of experience.

  • If you get too caught up in numbers, you can lose sight of what really matters. Steel is like a living thing—it changes depending on the day’s temperature and the type of charcoal used. So, observing the color and sensing those changes is the most important thing.

  • It may feel challenging at first, but start by watching for color changes. Over time, you’ll start to hear the “voice” of the steel.

  • 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.