• Sub-Zero Processing and Shiroyama Cutlery's Craftsmanship

  • KIREAJI’s Sub-Zero processing technology rapidly cools steel to below-zero temperatures, significantly enhancing the hardness and durability of the knives. This process, rooted in the craftsmanship and expertise of skilled artisans, results in knives with superior sharpness and lasting performance.

What is Sub-Zero Processing?

  • Typically, knife hardening involves heating the metal to high temperatures and then cooling it to increase its hardness. However, this method does not always achieve uniform hardening.

  • To overcome this, we employ advanced Sub-Zero processing. This technique involves cooling the steel to temperatures below 0°C using liquid nitrogen, ensuring that any unevenly hardened areas become uniformly hardened. Sub-Zero processing ensures consistent hardness throughout the knife, leading to exceptional durability.

Benefits of Sub-Zero Processing

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  • Sub-Zero processing greatly improves a knife’s performance. It enhances wear resistance, making the blade less likely to chip and maintaining its sharpness over an extended period. This process also stabilizes the blade’s dimensions, preventing deterioration over time. As a result, the knife’s sharpness is preserved longer, reducing the need for frequent sharpening.

Shiroyama Knife Workshop's Commitment

  • Shiroyama Knife Workshop takes great pride in their Sub-Zero processing techniques. To achieve the highest level of sharpness and durability, they use carefully selected materials and apply their extensive experience and technical expertise. Consequently, Shiroyama Knife Workshop’s knives are renowned for their remarkable sharpness and durability, earning high praise from professional chefs.

Sub-Zero Processed Knives Available at KIREAJI

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  • At KIREAJI, you can find knives treated with Shiroyama Knife Workshop’s Sub-Zero processing. These knives are ideal not only for professional chefs but also for anyone who enjoys cooking. Experience the unparalleled sharpness achieved through advanced Sub-Zero processing—try one for yourself today. Sub-Zero processing is a highly advanced technique that significantly enhances the quality of knives. Shiroyama Cutlery is dedicated to this technology, offering knives with exceptional sharpness and durability.

  • Enhance your culinary experience with a knife that has undergone Sub-Zero processing. Please take this opportunity to try our meticulously crafted products.
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KIREAJI's Three Promises to You

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    1. High-quality Japanese Knive

    We offer knives crafted by craftsmen from Sakai City.

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    2. Genuine Sharpness

    To ensure you experience sharpness, we provide a free Honbazuke by our skilled craftsmen.

  • 3. Lifetime Knife Use

    Every knife comes with a free Saya(Sheath) for durability. We also provide paid after-sales services with Sakai City Japanese knife workshop.