Technical Explanation of Aike in Japanese Traditional Knives

October 22, 2024

  • What is Aike?

    Aike is a specific type of error that can occur during the manufacturing process of traditional Japanese knives. Specifically, it refers to gaps or defects that appear on the blade's surface (hamon), often visible as black lines or small holes resembling black sesame seeds. This phenomenon arises during the joining of hagane (steel) and soft iron, and it is often an unavoidable aspect of knife production.

  • Causes of Aike

    The primary causes of Aike include:

    • Low-temperature forging work
      To create high-quality knives, intentional low-temperature forging is sometimes employed. This temperature adjustment is a technical choice to maintain the carbon content of the steel and enhance its sharpness.
    • Impurities during the joining process
      Aike can also occur if debris or impurities enter the joint between soft iron and hagane. This type of Aike is known as "Aike that can be removed by sharpening" and has a higher likelihood of being corrected with proper maintenance.

  • Types and Characteristics of Aike

    • Aike that can be removed by sharpening
      This type of Aike is caused by debris or impurities and is often correctable through sharpening. Such knives may also be relatively inexpensive to obtain.
    • Aike that cannot be removed by sharpening
      This type results from structural joining defects and may lead to rust. Typically, these knives are not available on the market.

  • Discovering Aike and Its Impacts

    Aike typically appears as black lines or small holes on the blade's surface and can be identified through visual inspection by experts. If a knife with Aike is used unknowingly, especially one with "non-removable Aike," it may be prone to rust and impact the knife's durability. However, removable Aike can often be corrected through proper maintenance.

  • KIREAJI's Quality Control and Aike

    Traditional Japanese knives are handcrafted by artisans, so it's common for them to initially show signs of "Aike." In particular, many stores sell knives without sharpening them, which can lead to customers unknowingly purchasing knives with Aike. However, KIREAJI implements strict quality control during the final sharpening process, thoroughly checking for the presence of Aike. This ensures that customers can purchase knives with confidence.

  • Conclusion

    Aike is a phenomenon that can occur during the production of traditional Japanese knives and does not necessarily indicate a defect. In fact, there are types of Aike that can be corrected through sharpening. When purchasing a knife, it's important to understand the types and impacts of Aike and consider buying from stores that conduct proper quality control.

Manufacturing Process of Japanese Knife

Japanese kitchen knives are made by heating and forging metal, then bonding the blade to the softer iron cladding. In the sharpening process, the blade is first roughly ground, then refined with finer stones, and finally polished with a finishing stone. In the handle construction process, the tang is inserted into the handle, and the brand name is engraved before the knife is packaged. This describes the manufacturing process of a Japanese kitchen knife.

Manufacturing Process of Japanese Knife

The Origin of Craftsmanship

  • The Future Beyond the Blade

    Life is much like a finely crafted blade.
    Hardships, struggles, and the endless question, “Is this the right path?”—these are the flames of the forge that shape and strengthen us.

  • As artisans, we know that raw materials don’t start out as something beautiful.
    We face uneven chunks of steel, hammering, shaping, heating, and cooling them to gradually draw out their potential. Life is no different. Within the struggles and challenges lies the hidden potential waiting to be revealed.

  • When you find yourself asking, “Is this enough?” or “Am I on the right track?” remember, those moments of doubt are like the strokes of a whetstone, sharpening your edge. Just as we never stop polishing a blade, you too must keep moving forward, embracing the questions and uncertainties. Beyond the struggle lies a blade that shines uniquely, just like you.

  • Both life and a knife sparkle only as much as the effort poured into them.
    Let us walk this path together, forging ahead, one strike at a time.

KIREAJI's Three Promises to You

  • japanese_knife_made_in_Sakai

    1. Exceptional Japanese Knives

    Our knives, crafted by Sakai City's master artisans, combine traditional techniques with carefully selected materials, delivering unrivaled sharpness and durability.

  • Honbazuke

    2. Genuine Sharpness

    We offer free Honbazuke sharpening performed by skilled craftsmen, ensuring that you experience the authentic sharpness of a true Sakai knife.

  • 3. Lifetime Knife Use

    Each knife comes with a free Saya (protective sheath) for added durability. We also offer after-sales service through a trusted Sakai City workshop to maintain your knife's performance.