Understanding Single-Bevel Japanese Knives
Traditionally, Japanese knives were ground with a single bevel — a distinctive grind made up of three parts: the shinogi surface, the urasuki, and the uraoshi. This was the dominant style until the late 19th and early 20th centuries, when Western influence brought double-bevel knives into wider use. Single-bevel knives are still made in Japan today, and they remain a standard for precision cutting. Here's how each part of the grind contributes to that.
What Is a Single-Bevel Knife?
A single-bevel knife is ground on only one side of the blade, while the other side stays flat. That asymmetry produces a narrower, more acute edge than a double-bevel knife, which is why single-bevel blades are the standard for precision work like sushi and sashimi prep. The edge angle typically runs 10 to 15 degrees per side, letting the blade pass through delicate ingredients with very little resistance.
Single-bevel knives are, in one sense, simpler to sharpen since only one side needs work on the stone. But that simplicity is deceptive — getting the geometry right takes more skill than sharpening a double-bevel edge, and mistakes can throw off the blade's cutting performance. Proper sharpening technique matters more here, not less.
Many high-quality single-bevel knives are handmade, and small variations in shape are common from blade to blade. That's a normal sign of hand craftsmanship rather than a defect, and it usually doesn't affect how the knife performs.
Single-Bevel Grind Terms and Definitions
The essential terms used to describe a single-bevel knife's grind:
- Shinogi Surface: The flat surface on the beveled side of the blade that leads down to the edge.
- Urasuki: The concave surface on the flat side of the blade.
- Uraoshi: The thin, flat rim surrounding the urasuki that reinforces the edge.
Shinogi Surface
The shinogi surface is the flat grind on the beveled side of the blade, tapering down to the edge. This geometry is what allows the narrow angle that makes single-bevel knives so sharp — grinding a second bevel onto the flat side would widen the angle and dull that edge back down. The shinogi is what makes ultra-fine, low-resistance slicing possible.
Urasuki
The urasuki is the concave surface on the flat side of the blade. It reduces drag during cutting, which helps keep food from sticking to the blade and results in cleaner cuts — especially useful for delicate ingredients like sashimi or vegetables. It also reduces how much of the flat side contacts the whetstone during sharpening, which makes it easier to maintain the blade's geometry over repeated sharpenings.
Uraoshi
The uraoshi is the thin, flat rim surrounding the urasuki. It reinforces the steel around the edge, adding some durability there, and it's the part of the flat side that actually contacts the whetstone during sharpening. Keeping the uraoshi flat is important for preserving the blade's geometry and getting a consistent edge each time you sharpen.
Why Single-Bevel Knives Matter
Understanding this grind isn't just trivia for knife enthusiasts — it explains why single-bevel knives cut the way they do. They represent a specific, longstanding approach to edge geometry, and they remain a common choice among professionals doing precision fish and vegetable work.
Whether you're preparing sashimi, cutting garnishes, or just curious about the craft, understanding a single-bevel knife's construction changes how you think about using and maintaining one.
Knowing the anatomy — the shinogi surface, the urasuki, the uraoshi — also helps you sharpen it correctly, which matters more for a single-bevel edge than almost any other knife you'll own.
Frequently Asked Questions
Are single-bevel knives better than double-bevel?
Single-bevel knives cut with less resistance and give a cleaner slice on precision work, but they take more skill to use and maintain well. Double-bevel knives are more forgiving and versatile for general kitchen use.
Can I use a single-bevel knife if I'm left-handed?
Most single-bevel knives are ground for right-handed use. Left-handed versions are available from some makers, including Yoshihiro Cutlery — check the product listing for handedness before buying.
What foods are best suited for single-bevel knives?
They're built for delicate, precise slicing — sashimi, sushi prep, garnishes, and fine vegetable work. They're not the right tool for bone, frozen food, or hard squash.