Urasuki—The Inner Hollow Grind
Urasuki (裏スキ) is the recessed area ground into a scissor blade’s inner face. It forms part of the blade geometry alongside the cutting edge and contact surfaces. Its shape and service needs depend on the design and condition of the pair; the name alone does not establish quality or remaining life.
Turn a symptom or feature into a precise service brief
Locate the broad part family, use maker wording, record the observation, and ask a scoped service question. Apply to Urasuki—The Inner Hollow Grind
- 01 Locate Start with tip, blade, pivot, shank, rings, rest, or contact area.
- 02 Name Match the exact model's diagram and terminology.
- 03 Describe Record visible condition, sound, resistance, incident, and baseline change.
- 04 Brief Ask what is in scope, what work is proposed, and how return is verified.
Do not inferOne photograph, sound, feel, pull, fold, or visible mark cannot identify a cause or authorize adjustment or repair.
Why It Matters
KOUHO describes the inner recess as important to the behavior of the assembled scissors. Its explanation connects the shape of that surface with opening, closing and cutting feel. This is a maker’s account of geometry, not a measurement of friction or a guarantee that hair fragments clear themselves. KOUHO explanation.
A hollow creates relief between adjacent surfaces, but the assembled tool also has contact near its edge and pivot. The complete arrangement matters. “Near-zero friction,” a suction effect holding hair, and automatic self-cleaning are not established by the reviewed evidence. Routine care still needs the maker’s instructions.
Three locations to distinguish
Identify the locations separately. A three-part description is useful for orientation, but it does not prescribe universal blade proportions or a manufacturing standard:
| Feature | Location | Useful distinction |
|---|---|---|
| Outer grind | Outside of the blade, leading toward the edge | A convex or beveled profile does not specify the inner recess |
| Urasuki | Recess on the inner face | Describe its position and geometry for the actual model |
| Contact land or bearing area | Where the design supports contact between components | Confirm the maker’s part name and location before discussing repair |
The Hamaguri-ba reference concerns an outer profile. The ride-line reference explains why an edge-adjacent strip and a pivot-adjacent bearing area should be identified separately. A translated term such as uraoshi needs its own maker context; it should not be used to prescribe a universal scissor rim width or angle.
Trade-offs
The useful question is whether the blade retains the geometry intended for its work. A visible hollow by itself does not certify manufacturing quality, and its depth does not supply a ranking between Japanese and European scissors. It also cannot tell a buyer how much material a previous service removed.
For a used pair, request the model identification, service history and an assessment of current cutting behavior. A photograph can document condition, but it cannot certify the blade’s remaining restoration allowance. If a seller claims a particular number of sharpenings remains, ask how that number was established for that pair.
Manufacturing and geometry
KOUHO’s account makes the inner surface a deliberate part of the blade design. It does not establish one production sequence or a fixed number of factory stages for every maker. Likewise, a list of manufacturing operations does not supply a depth tolerance for a completed blade. Maker account.
For service, separate work at the cutting edge from work on the adjacent land and deeper re-forming of the inner hollow. Wolff Industries describes equipment for re-establishing a ride line; that description does not mean every sharpening service re-grinds the entire recess. Equipment specification.
Maintenance Considerations
A service request should describe the symptom and circumstances: which part of the cut fails, whether the problem followed a drop or previous sharpening, and whether opening or closing feels different. These observations help the technician investigate; they do not establish a hollow-grind fault by themselves.
Scissors Yamato’s repair terms describe work involving the inner edge land, blade bow, twist and overall balance. The provider may decline hollow repair depending on the blade and its condition. Its documented repair case shows that restoration can be possible, correcting the earlier claim that there is never a recovery path. Repair terms, documented case.
Before authorizing work, ask what geometry will change, whether coatings or components could be affected, and what the provider will do if restoration proves unsuitable. Keep the written scope with the service record. This is more useful than assuming every technician includes the same operations under “sharpening.”
A useful service record
Separate observations made before and after service. This gives the next technician something specific to compare if a problem returns.
| Record | Useful detail |
|---|---|
| Identification | Maker, model, handedness and any finish or special pivot arrangement |
| Starting condition | Where the cut fails, how closure feels and when the change began |
| Agreed work | Edge sharpening, land work, hollow restoration or component changes, as applicable |
| Assessment result | What the provider found, what it changed and any limits it identified |
| Return check | The intended cutting task and whether the reported symptom remains |
Keep observations distinct from conclusions. “Hair folds at the tip” records behavior; “the hollow is exhausted” requires a technical finding. A useful report explains how the proposed work relates to the observed fault.
Sources and limits
The former counts of 20–30 and 5–10 sharpenings had no named-model service evidence and are withdrawn. No replacement lifetime figure is inferred here. The cited repair example is evidence of one completed intervention, while the service terms explain assessment limits; neither forecasts another blade’s life.
The maker explanation and repair records below support different parts of this account; none supplies a universal depth specification.
See Also
Best Japanese scissors by tier → · Ride line · Touch point terminology
Key Characteristics
- Recessed surface on the inside of a blade
- Distinct from the outer grind and adjacent contact lands
- Exact geometry depends on the scissor design
- Restoration requires assessment of the actual pair
Best For
- Understanding inner and outer blade geometry
- Describing a service problem accurately
- Comparing repair scope and evidence
Sources
4 sources- 🇯🇵 KOUHO: Urasuki and the inner blade surface (manufacturer educational)
- 🇯🇵 Scissors Yamato: Urasuki repair scope and conditions (specialist service)
- 🇯🇵 Scissors Yamato: Documented inner-hollow repair case (sharpener blog)
- Wolff Industries: Ookami Gold scissors sharpening system (manufacturer product listing)
Frequently Asked Questions
4 answers you can open one at a timeWhat is urasuki on scissors?
Urasuki is the recessed or hollowed area on a blade’s inner face. KOUHO describes it as an important part of the blade geometry. It is distinct from the outer edge profile and the contact surfaces beside the recess.
Does a deeper hollow always make better scissors?
No universal depth or depth-to-quality ranking is established by the reviewed sources. The hollow works within a complete blade design. Compare the maker’s intended geometry and the condition of the actual pair.
Can an inner hollow be restored?
Sometimes. Scissors Yamato documents restoration work but also states that blade shape, condition and faults can make a proposed repair unsuitable. A published successful case does not guarantee another pair is repairable.
How many sharpenings can urasuki survive?
The reviewed sources do not provide a universal sharpening count. Service history, the work performed and remaining blade geometry matter. Ask for an assessment instead of treating five, ten or thirty services as an expiry limit.
Comments & questions
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