What is Japanese knife steel called?

To understand Japanese knives, one must first understand the steel that defines them. Known as “Wako” (和鋼, Wa-gane), this traditional Japanese blade steel has long been admired for its purity, sharpness, and ability to carry centuries of craftsmanship in every cut.

The Purity of Wako

Unlike ordinary steels, Wako was historically produced using satetsu (iron sand) smelted in a tatara furnace, yielding exceptionally pure iron with minimal impurities. This purity creates a fine and uniform grain structure, allowing blades to take on an edge of remarkable sharpness and refinement.

Sharpness and Longevity

The hallmark of Wako—and its modern successor, Yasuki Hagane—is the ability to hold a razor-sharp edge while maintaining durability. A properly forged blade of Wako steel is not just sharp on the first cut; it continues to perform with consistency, rewarding both the artisan who forged it and the chef who wields it.

From Japanese Swords to Kitchen Knives

Wako’s legacy stretches back to the forging of the katana, where purity and resilience were vital. Today, this tradition lives on in kitchen knives. Hitachi Metals’ Yasuki Hagane carries forward this spirit, giving us the modern White Steel (Shirogami) and Blue Steel (Aogami) that remain the gold standard for professional Japanese knives.

• White Steel (Shirogami): Extremely pure carbon steel, capable of reaching a keen, refined edge, favored by sushi and kaiseki chefs.
• Blue Steel (Aogami): Enhanced with tungsten and chromium for improved durability and edge retention, making it ideal for heavy-duty use.

More Than a Material

Wako—and the Yasuki steels it inspired—represent more than metallurgy. They embody Japan’s philosophy of precision, patience, and respect for food. Each blade forged from this steel is a cultural vessel, linking the traditions of the swordsmith to the artistry of today’s kitchen.

To speak of Japanese knives is to speak of Wako: steel that has been refined not only by fire and hammer, but by centuries of devotion.