Understanding Blade Construction: Single-Bevel vs. Double-Bevel Knives

Pick up any serious Japanese knife and you'll eventually see a specification that reads "single bevel" or "double bevel" — sometimes written in Japanese as 片刃 (kataba) or 両刃 (ryōba). It sounds technical. It is technical. But it's also one of the most consequential decisions in Japanese knife design, and understanding it changes how you see every knife you'll ever buy.

This is not a subtle difference. Single-bevel and double-bevel knives look almost identical from above, but they cut differently, require different technique, sharpen differently, and exist for genuinely different purposes. Choosing the wrong one for your cooking style isn't just an inconvenience — it can make a knife feel actively difficult to use.

This Japanese knife guide explains both bevel types completely: what they are at the geometry level, why each exists, which knife types use each, and — most practically — which one belongs in your kitchen.

Table of Contents

• Key Takeaways
• What Is a Bevel?
• Single-Bevel Knives (片刃 — Kataba)
• Double-Bevel Knives (両刃 — Ryōba)
• Side-by-Side Comparison
• Sharpening: Where the Real Difference Shows Up
• The Left-Handed Cook: A Note Worth Making Clearly
• Which Type Does Seido Knives Make?
• Which Should You Choose?
• Frequently Asked Questions

Key Takeaways

• Single-bevel (kataba) knives are sharpened on one side only — extraordinarily precise, specialist tools for sushi, sashimi, and fine vegetable work. Right-handed by default.
• Double-bevel (ryōba) knives are sharpened on both sides — versatile, ambidextrous, and accessible at every skill level. The right choice for almost all home cooks.
• The urasuki (hollow on the flat side of a single-bevel knife) reduces drag and makes back-face maintenance possible. It is a functional design feature, not decorative.
• Left-handed cooks should start with double-bevel knives; single-bevel knives require a specifically sourced left-handed version.
• Sharpening single-bevel knives is more demanding than double-bevel — maintaining the shinogi line and urasuki requires practiced technique.
• Most home cooks need double-bevel knives. Add a Yanagiba or Usuba later if your cooking moves into traditional Japanese territory.
• In the comparison between single bevel vs double bevel knives, the bevel knives that belong in your kitchen are those that fit your skill level and intended use.

What Is a Bevel?

Before comparing the two, it helps to understand what a bevel actually is.

The bevel is the angled surface ground into the side of a blade to create its cutting edge. Think of it as the ramp that leads down to the sharp tip of the knife. Every knife has at least one bevel. What varies — and what defines the entire character of a knife — is whether that bevel exists on one side of the blade or both, and at what angle.

The bevel angle determines how acute (fine) or obtuse (thick) the cutting edge is. A narrower angle produces a sharper, finer edge that glides through food with less resistance. A wider angle produces a more durable edge that can handle harder, denser tasks without chipping. Both bevel type and bevel angle work together to define what a knife is optimized for.

Single-Bevel Knives (片刃 — Kataba)

What It Is

A single-bevel knife — 片刃 (kataba) in Japanese — is sharpened on only one side. The front face of the blade has the angled grind that creates the cutting edge. The back face is either completely flat or very slightly concave.

That slight concavity on the back is called the urasuki (裏隙) — one of the most important and least-discussed features in Japanese knife design. The urasuki creates a hollow channel along the flat side of the blade that serves two purposes: it reduces the surface area in contact with food during a cut (reducing drag and stiction), and it makes the back face significantly easier to flatten and maintain on a whetstone.

The angled front grind has its own anatomy. The shinogi (鎬) is the ridge line that separates the flat face of the blade from the beveled grind — a clean, visible line that runs along the upper portion of the blade face on traditional Japanese knives. Below the shinogi, the grind descends to the edge at an angle typically between 10° and 17°.

The result of this geometry is an asymmetrical blade — flat on one side, angled on the other — that produces an edge of extraordinary sharpness and precision.

Why Single-Bevel Geometry Exists

Single-bevel knives are not a historical accident or a tradition maintained for its own sake. The geometry solves a specific problem: how do you cut through delicate, wet, slippery food — raw fish, soft vegetables, tofu — in a single motion, with perfect control over the thickness of each slice, without tearing, compressing, or bruising what you're cutting?

The answer is the chisel-like single-bevel edge. Because only one side is ground, the edge is finer and more acute than almost any double-bevel knife can achieve. Because the back is flat (with the urasuki hollow), the blade passes through food with almost no lateral resistance — food doesn't cling to the flat side. And because the geometry is asymmetrical, the blade naturally wants to travel in a straight, predictable line through the ingredient rather than drifting left or right.

This is why the single-bevel design is inseparable from traditional Japanese cuisine — sushi, sashimi, kaiseki, and the fine vegetable preparations that require paper-thin consistency and zero cell damage.

The Handedness Problem

Single-bevel knives are not ambidextrous. A standard single-bevel knife is ground for right-handed use: the bevel is on the right side of the blade, and the flat back faces left. When a right-handed cook uses a pull stroke, the geometry guides the blade exactly where it should go.

A left-handed cook using a right-handed single-bevel knife will fight the geometry with every cut — the blade will want to steer away from the correct line. Left-handed versions of single-bevel knives exist, but they must be specifically ordered and typically cost the same as or more than standard versions. This is not a minor inconvenience — it is a fundamental incompatibility that makes single-bevel knives inappropriate for left-handed cooks who haven't sourced a lefty-specific blade.

Which Knife Types Are Single-Bevel

Traditional Japanese single-bevel knives are specialized tools, each designed for a narrow range of tasks performed at a very high level:

Yanagiba — The sashimi slicer. Long, thin blade designed for drawing pull strokes through raw fish without tearing. The single-bevel geometry ensures each slice is clean, with the cell structure of the fish intact rather than crushed. The standard tool of the sushi chef. Typically 270–330mm.

Usuba — The traditional vegetable knife of Japanese professional kitchens. Single-bevel, rectangular blade for paper-thin cuts and katsuramuki (the rotary peeling technique used to create translucent sheets of daikon and other root vegetables). More demanding in technique than the Nakiri, its double-bevel counterpart.

Deba — A heavy, thick-spined single-bevel knife for breaking down whole fish. The weight and geometry allow it to pass through bones and cartilage cleanly. The spine thickness provides stability for heavier work while the single-bevel edge maintains precision at the cutting face.

Takohiki — A regional variant of the Yanagiba used primarily in Tokyo (Kanto region), with a squared rather than pointed tip. Used for octopus and other seafood preparations where the straight tip is an advantage.

Honesuki — A poultry butchery knife with a triangular, rigid blade for separating joints and working around bones. Some versions are single-bevel; Western-influenced double-bevel versions also exist.

Double-Bevel Knives (両刃 — Ryōba)

What It Is

A double-bevel knife — 両刃 (ryōba) in Japanese — is sharpened on both sides of the blade. The two beveled surfaces meet at the center of the edge, forming a V-shaped or lenticular (convex) profile depending on the grind style.

Most double-bevel knives are ground symmetrically at 50/50 — equal angles on each side. But asymmetric double-bevel grinds also exist: a 70/30 grind has a steeper angle on one side and a shallower angle on the other, which gives the blade some of the steering behavior of a single-bevel while remaining usable with both hands. Japanese-style double-bevel knives are typically ground at 6°–8° per side, significantly more acute than the 15°–20° per side typical of Western chef's knives.

Why Double-Bevel Geometry Exists

The double-bevel design solves a different problem from the single-bevel: how do you make a versatile, intuitive cutting tool that works well across a wide range of tasks, ingredients, and users without requiring specialized technique?

Double-bevel knives are inherently more stable in the hand. The symmetric geometry means the blade doesn't want to steer in either direction — it tracks straight through whatever it's cutting regardless of the angle of approach. This makes double-bevel knives forgiving of technique variation, which is exactly what home cooks and generalist professional cooks need.

The double-bevel design also makes these knives ambidextrous: anyone can pick up a double-bevel knife and use it comfortably regardless of their dominant hand. And sharpening is more intuitive — you maintain the same angle on both sides, which is something most home sharpeners can learn quickly.

Which Knife Types Are Double-Bevel

Most of the Japanese knives familiar to Western home cooks are double-bevel:

Gyuto — The Japanese chef's knife. Double-bevel, typically 210–270mm, and the most versatile knife in the Japanese kitchen. Handles meat, fish, vegetables, and herbs with equal capability.

Santoku — The everyday all-rounder. Shorter and flatter than a Gyuto, designed for up-and-down chopping rather than rocking cuts. Double-bevel, typically 165–180mm.

Nakiri — The home cook's vegetable knife. Rectangular blade, blunt tip, double-bevel — the more accessible, easier-to-maintain counterpart to the professional single-bevel Usuba.

Kiritsuke — Traditionally single-bevel and reserved for head chefs. Modern production Kiritsuke knives are almost always double-bevel, which makes the distinctive angled tip available to home cooks without requiring single-bevel technique.

Petty — The compact utility knife. Double-bevel, 120–180mm, for detailed work and in-hand cutting.

Sujihiki — The double-bevel counterpart to the Yanagiba. Long, narrow slicer for proteins, designed for pull strokes through larger cuts of meat or fish. More accessible than the Yanagiba because the double-bevel geometry is forgiving of imperfect technique.

Side-by-Side Comparison

Sharpening: Where the Real Difference Shows Up

The sharpening difference between single-bevel and double-bevel knives is more significant than most guides acknowledge — and it's often the decisive factor in which type a home cook should choose.

Sharpening a Double-Bevel Knife

Double-bevel sharpening follows a consistent logic: hold the blade at the correct angle (typically 12°–15° per side for Japanese knives), work both sides on a whetstone progressing through grits, raise a burr on one side before switching, then remove the burr with a final light pass. The process is learnable for most home cooks with a good whetstone and some practice. The symmetry of the grind means mistakes on one side can be corrected on the other.

For a full guide, see: How to Sharpen a Knife with a Whetstone →

Sharpening a Single-Bevel Knife

Single-bevel sharpening is more nuanced. The bevel side is sharpened at a consistent angle (typically 10°–17°) — only on that one side. The flat back (ura) is not sharpened at an angle at all; instead, it is simply flattened on the whetstone to remove the burr raised during front sharpening, and to maintain the integrity of the urasuki hollow.

The critical constraint is the shinogi line. Sharpening must maintain the shinogi at its original height and angle — if the grind is taken too high, the geometry of the knife changes and performance degrades. Maintaining that line requires a learned feel that takes deliberate practice to develop.

Practically, this means single-bevel knives are not ideal for home sharpeners who are still developing their whetstone technique. A poorly sharpened single-bevel knife will steer, catch, and frustrate in ways that obscure its true capability. Many experienced cooks send their single-bevel knives to a professional sharpener for the major work and do only minor touch-up maintenance at home.

The Left-Handed Cook: A Note Worth Making Clearly

If you are left-handed and considering Japanese knives, the bevel question matters more for you than for anyone else reading this guide.

Every single-bevel knife you encounter is almost certainly made for right-handed use unless explicitly stated otherwise. Using it left-handed is not a workaround or a minor adjustment — it produces cuts that steer incorrectly, require compensating pressure, and fatigue the wrist in ways that right-handed users never experience.

Left-handed versions of the Yanagiba, Usuba, and Deba exist and are produced by quality makers — but they must be specifically requested and may carry a premium or longer lead time.

Double-bevel knives have no such limitation. A Gyuto, Santoku, or Nakiri works identically for right- and left-handed cooks. If you are left-handed, the double-bevel category is the right starting point — and for most home cooking purposes, it is all you will ever need.

Which Type Does Seido Knives Make?

Seido's collection focuses on double-bevel knives — Gyuto, Santoku, Kiritsuke, Nakiri, Petty, and utility knives in VG10 and AUS10 Damascus steel. This reflects the intended audience: home cooks and enthusiastic beginners who want genuine Japanese knife performance with the versatility and accessibility that double-bevel geometry provides.

The double-bevel focus is also a deliberate quality decision. Producing excellent single-bevel knives requires specialized grinding equipment and a different set of finishing skills than double-bevel production. Seido's investment is in the double-bevel category, and the specifications — 12-degree edge angle, 67-layer Damascus cladding, VG10 or AUS10 core — reflect that focus.

Browse Seido's double-bevel knife collection →

Which Should You Choose?

The decision comes down to three questions:

What are you cooking? If your kitchen centers on everyday home meals — vegetables, proteins, herbs, general prep — a double-bevel knife handles all of it with less technique overhead and more forgiveness. If your kitchen includes serious sushi or sashimi preparation, traditional Japanese vegetable work, or professional-level fish butchery, single-bevel knives are the purpose-built tools for those tasks.

What is your skill level? Single-bevel knives reward experienced technique and punish imprecision. A beginner using a Yanagiba will fight the geometry until the cutting motion becomes natural — and that takes deliberate practice. A double-bevel Gyuto or Santoku rewards anyone who picks it up, regardless of experience level.

Which hand do you use? If you are left-handed, start with double-bevel. The single-bevel path requires sourcing a left-handed knife, which adds cost and complexity to what is already a significant learning curve.

For most home cooks: start with double-bevel. Build your technique. Learn to sharpen on a whetstone. When you find yourself wanting to do more precision work with fish or traditional Japanese vegetable preparations — and when your sharpening skills can support single-bevel maintenance — add a Yanagiba or Usuba as a specialist tool. That is the sequence that most serious home cooks follow.

Frequently Asked Questions

What is the difference between single-bevel and double-bevel Japanese knives?

A single-bevel knife (kataba) is sharpened on only one side, creating an asymmetric edge of exceptional precision suited for traditional Japanese cutting techniques. A double-bevel knife (ryōba) is sharpened on both sides, creating a symmetric V-shaped edge that is more versatile, easier to use, and works for both hands. Most home cooks use double-bevel knives; single-bevel knives are specialist tools for sushi, sashimi, and fine vegetable work.

Is a single-bevel knife sharper than a double-bevel knife?

Single-bevel knives can achieve a more acute edge angle (10°–17° total) than most double-bevel knives (12°–16° total), which allows for finer, more precise cuts in specific applications. However, "sharper" depends on what you're cutting and how well the knife has been sharpened. A well-sharpened double-bevel Japanese knife at 12° per side is significantly sharper than a poorly maintained single-bevel knife at any angle.

Can a left-handed cook use a single-bevel Japanese knife?

Not a standard one. Most single-bevel knives are made for right-handed use — the bevel is ground on the right side of the blade. Using a right-handed single-bevel knife with your left hand produces cuts that steer incorrectly. Left-handed versions exist from quality makers but must be specifically requested. Left-handed cooks are almost always better served by double-bevel knives, which are ambidextrous.

Which Japanese knives are single-bevel?

The main single-bevel Japanese knives are the Yanagiba (sashimi slicer), Usuba (professional vegetable knife), Deba (fish butchery), and Takohiki (Kanto-region sashimi knife). Most other Japanese knives you encounter — Gyuto, Santoku, Kiritsuke, Nakiri, Petty — are double-bevel.

Is the Kiritsuke single-bevel or double-bevel?

Traditionally, the Kiritsuke was a single-bevel knife used exclusively by head chefs (itamae) in Japanese professional kitchens. Modern production Kiritsuke knives — including those in Seido's range — are almost always double-bevel, which makes the distinctive angled tip and flat profile accessible to home cooks without requiring single-bevel technique or right-hand-only use.

Are double-bevel Japanese knives easier to sharpen?

Yes, significantly. Double-bevel sharpening requires maintaining a consistent angle on both sides of the blade — a learnable skill for most home cooks with a quality whetstone and some practice. Single-bevel sharpening requires maintaining the shinogi line, the urasuki hollow, and the flat back simultaneously, which takes deliberate practice and a developed feel for the geometry. Many home cooks send their single-bevel knives to professional sharpeners rather than attempting full maintenance at home.

What does "70/30 grind" mean on a double-bevel knife?

A 70/30 grind means one side of the blade is ground at a steeper angle (70% of the total bevel) and the other side at a shallower angle (30%). This gives the knife some of the steering behavior of a single-bevel knife while remaining ambidextrous. It's common on some Japanese-style knives designed to combine precision cutting with double-bevel accessibility. A 50/50 grind — equal angles on both sides — is more common and fully ambidextrous.

Should a beginner start with a single-bevel or double-bevel knife?

Double-bevel, without exception. Single-bevel knives require specific cutting technique, specific sharpening skills, and — for left-handed cooks — a specifically sourced left-handed version. Double-bevel knives are forgiving, versatile, and accessible to any skill level. Start with a Gyuto or Santoku in VG10 or AUS10 stainless. Add a single-bevel specialist knife once you've developed your technique and have a specific use case for it.

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Related reading from Seido Knives:
How to Choose Your First Japanese Chef Knife →
Japanese Knife Prices: What You Should Expect to Pay →
Honing vs. Sharpening: What's the Difference? →
How to Sharpen a Knife with a Whetstone →
Browse Seido's Double-Bevel Collection →
Check Out Our Complete Japanese Kitchen Knives Guide →