What Is a Single-Bevel Uraoshi? (Grind Specs Guide)
Uraoshi is the narrow, flat land around the hollow on the back of a traditional single-bevel knife. It is not a second bevel, and the hollow should stay recessed. Sharpen the main bevel to match its existing angle, then use a fine stone and light pressure on the uraoshi to remove the burr. Preserve the knife’s original geometry.
A few extra strokes on the back can change more than the edge. They can widen the uraoshi land, shrink the hollow, and alter how the knife cuts. If you are unsure what to grind, stop and inspect before continuing. The safest guide is the shape already on your knife, not a universal angle or stroke count.
Identify the Uraoshi, Urasuki, and Bevel
The uraoshi is the narrow, flat rim around the recessed hollow on a single-bevel knife’s back. The hollow is called the urasuki. The broad ground face on the opposite side is the bevel. Each part has a job, so sharpening should preserve their existing shape.
A yanagiba, usuba, or deba may have this construction. An ordinary double-bevel knife does not use the same back-side method. Steel, cladding, hardness, and grind vary by maker, so inspect the specific blade rather than assuming all Japanese knives share one set of specs.
What the terms and measurements mean
These measurements help you recognize the geometry, not prescribe a grind. There is no universal factory width for uraoshi, and the edge angle can vary by knife. Use the visible land and bevel as references, then preserve them unless a qualified sharpener is correcting damage.
| Feature | What to look for | Practical reference |
|---|---|---|
| Uraoshi | Narrow, flat land around the hollow | About 0.5–1.5 mm is a visual reference, not a target |
| Urasuki | Recessed hollow in the back | Keep it recessed; do not flatten it |
| Main bevel | Ground face on the front | Follow the existing angle; about 10–15° on the bevel side is common, not universal |
| Back contact | Land touching the stone | The land is the contact surface, not the hollow |
To inspect, clean and dry the blade, then view the back in good light. Tilt it so the land and hollow catch the light differently. Look for chips, uneven wear, or a land that is already broad. Do not estimate width by grinding until it “looks right.” If the hollow or edge is damaged, get an assessment before removing more steel.
Sharpen the Bevel and Maintain the Uraoshi
Sharpening starts on the main bevel, where you restore the cutting edge. Keep the existing bevel angle steady and work until a small, continuous burr forms at the edge. Then use a fine stone on the uraoshi with light pressure to remove that burr without grinding the hollow.
Step-by-step sharpening sequence
- Check the knife and stone. Identify the bevel side, uraoshi land, and hollow. Check for chips and confirm the stone is flat. Prepare or soak it only as its maker directs.
- Set the existing bevel on the stone. Use the angle already present rather than imposing a new one. Many Japanese knife edges work around 10–15° on the bevel side, but knife and maker differences matter. Avoid shifting the shinogi line, the boundary between the main bevel and the blade face.
- Sharpen in controlled sections. Keep contact consistent as you work along the edge. Use enough pressure to sharpen, not to force the blade into the stone. Continue until you can feel a small, continuous burr on the ura side.
- Refine the edge. A 1,000-grit stone is a common maintenance starting point. A finish around 3,000–6,000 grit is common, though the right finish depends on the knife and task. Follow the stone maker’s guidance and the knife’s condition.
- Maintain the uraoshi. Use a flatter, finer stone. Lay the uraoshi land flat and make a few gentle strokes. The hollow should remain recessed. Stop when the burr is gone; there is no reliable universal stroke count.
A burr is a thin lip of metal pushed to the opposite side of the edge during sharpening. It helps show that the bevel has reached the edge, but a large burr is not a goal. If it will not clear with light uraoshi strokes, return to the bevel for minimal, light passes, then check again.
Choose pressure and grit by the work
Use the coarseness and pressure needed for the repair, not the most aggressive tools available. A finer stone is suited to light back-side maintenance; a coarse stone may remove metal quickly and widen the land. Do not use a coarse powered grinder or uncontrolled strokes: heat and poor control can damage or reshape the edge.
| Situation | Sensible approach | Avoid |
|---|---|---|
| Routine edge maintenance | Start near 1,000 grit on the bevel; finish to suit the knife and task | Changing the bevel angle by guesswork |
| Light burr removal | Fine, flat stone; a few light strokes on the uraoshi | Repeated hard grinding on the back |
| Visible chip or uneven geometry | Pause and assess repair needs | Grinding until the chip disappears without a plan |
| Land looks wider after sharpening | Stop and compare with the original geometry, if known | Treating a wider land as a better result |
Deburr, Clean, and Protect the Blade
Deburring means removing the thin metal lip left by sharpening while keeping the edge crisp. Use light, controlled contact and check the edge rather than relying on a fixed number of strokes. After sharpening, rinse and dry the blade, including its back and the area near the handle.
Once the burr is removed, inspect the edge under good light and test it with care on an appropriate food or cutting medium. If you still feel a wire-like lip, use minimal alternating, light passes on the bevel and back as needed. Do not press hard or keep grinding just to make the back look uniformly polished.
Dry the knife right away. Carbon steel can rust and may react with acidic foods; stainless steel is more corrosion-resistant, but it still benefits from prompt cleaning and drying. For carbon steel storage, apply a thin layer of food-safe protective oil. Use a blade guard or saya, a fitted wooden sheath, to protect the edge.
Use and Present a Single-Bevel Knife Safely
A single-bevel knife is designed around an asymmetric edge, so keep its original geometry during sharpening and use. Do not sharpen the back as if it were a second bevel. The bevel side and uraoshi work together; changing either can affect how the blade tracks and releases food.
Illustrative sharpening scenarios
These examples show how to choose a next step; they are not reports of specific repairs. When I assess a blade, I first ask whether the problem is a dull edge, a burr, a chip, or altered geometry. That distinction helps prevent a small maintenance task from becoming an unnecessary reshaping job.
- The knife is dull, but the back looks intact. Sharpen the main bevel at its existing angle until a small, continuous burr forms. Refine the edge, then use light uraoshi contact to clear the burr.
- The edge has a small chip. Stop routine sharpening and assess how much steel must be removed to repair it. Extensive repair can change the edge and may call for a professional sharpener.
- The uraoshi land appears broad or uneven. Do not grind the hollow flat or try to reduce the land by aggressive back grinding. Heavy or repeated work can reduce the hollow and change release or steering behavior. Seek expert repair if geometry needs correction.
- The burr remains after a few light strokes. Return to the bevel for a few minimal passes, then check again. Do not add pressure or keep making back-side strokes without checking the edge.
Excessive pressure can round the edge, while heavy uraoshi grinding can widen the land and reduce the hollow. These changes are difficult to reverse and may require professional thinning or repair. Stop if you cannot maintain flat contact on the land or if the blade’s shape is changing.
FAQ: Single-Bevel Uraoshi Grind Specs
These short answers summarize the key limits: preserve the existing bevel, keep the hollow recessed, and use the uraoshi only for controlled back-side contact. The figures below are practical references, not maker-independent requirements. If the knife is chipped, warped, or already has altered geometry, pause before removing more steel.
What is uraoshi on a Japanese knife?
It is the narrow, flat land around the recessed hollow on the back of a traditional single-bevel knife.
What is the hollow called?
The hollow is called the urasuki. It should remain recessed rather than being flattened during sharpening.
How wide should the uraoshi be?
There is no universal factory width. Roughly 0.5–1.5 mm is a visual reference, but preserve the land your knife already has.
Do I sharpen the uraoshi like a second bevel?
No. The uraoshi is laid flat on a fine stone for light burr removal. Do not create a second bevel on the back.
What angle should I use on the main bevel?
Follow the existing bevel. About 10–15° on the bevel side is common for many Japanese edges, but it is not a universal setting.
How many strokes should I make on the back?
There is no reliable universal count. Make a few gentle strokes and stop when the burr is gone.
What grit should I use?
A 1,000-grit stone is a common maintenance start for the bevel; many edges finish around 3,000–6,000 grit. Use a flatter, finer stone for light uraoshi maintenance.
Can I use this method on a double-bevel knife?
Not as described. This method is for single-bevel knives such as yanagiba, usuba, and deba.
What happens if I grind the back too much?
The uraoshi can widen and the hollow can shrink. That may affect food release or steering, and the geometry can be difficult to restore.
How should I store the knife after sharpening?
Rinse and dry it promptly. For carbon steel, apply a thin layer of food-safe oil before storage and protect the edge with a guard or saya.
(This article was written by one of our staff writers, Julian R. Hayes. Visit our Meet the Team page.)
