The Craft Behind Ishizuchi ZDP189 Knives

Understanding the Handle Structure and What Makes It Unique

At Omakase, we take pride in offering knives that reflect authentic Japanese craftsmanship. The Ishizuchi ZDP189 series is no exception. Recently, a few customers have noticed a visible cavity in the handle structure and reached out with questions. We’d like to take this opportunity to explain the design intention and the tradition behind it—with full transparency.

 

Traditional Construction, Made to Last

Each knife in the Ishizuchi ZDP189 series is crafted using a traditional Tosa-style technique that combines both softwood and hardwood in the handle. This method is more complex than using hardwood alone and is typically reserved for higher-grade knives due to the skill and material cost involved.

Unlike mass-produced knives that use a fully sealed adhesive joint, this knife features a longer tang that is:

  • Manually inserted into the handle

  • Fixed with minimal adhesive to allow for future rehandling

  • Secured using hand-drilled cavities—which may remain visible to the eye

What may appear to be a "gap" is in fact a hallmark of handwork. It reflects not a flaw, but the precision of a skilled artisan. No machines, no shortcuts—just time-honored knifemaking.

 

Why This Matters

This approach to construction means your knife is designed to be durable, repairable, and adaptable over time. The visible cavity is intentional: a result of manual assembly and not something found in machine-made knives, especially those made outside Japan.

 

On Water Ingress and Stainless Steel

We understand concerns about moisture entering the handle. Here’s what you should know:

  • The blade steel used—ZDP189—is stainless and highly resistant to rust.

  • In traditional Japanese knifemaking, even if minimal rust forms internally over time, it can help bond the tang to the wood more securely, reinforcing the joint.

  • As an added measure, we recommend storing your knife blade-down or horizontally after washing to avoid moisture retention inside the handle.

 

In Summary

What you see is not a defect, but a detail—one that reflects:

  • Skilled handcraftsmanship

  • Traditional Tosa knifemaking

  • A construction method built for longevity

We believe this transparency helps deepen your appreciation of the knife—and the artisan behind it. Thank you for choosing to own a piece of Japanese craft tradition.