Blade Curvature (反り)
Scissor anatomyTurn 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 Blade Curvature (反り)
- 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.
Description
Blade curvature (sori) is a deliberate lengthwise bow used in some scissor designs to manage blade contact from pivot to tip.
Blade Curvature (反り, そり / Sori — also おがみ / Ogami)
Quick look
- What it is: A model-specific lengthwise curvature used in some blade designs
- Measurement: Defined by the maker’s geometry and inspection method
- Purpose: Helps manage blade contact through closure
- Creation: May involve forming, setting, hand adjustment, fixtures, or measurement, depending on the maker
- Japanese terms: 反り (そり, sori) and おがみ (ogami)
Why it matters
Blade curvature is one part of the relationship between two scissor blades. The intended bow varies with blade length, stiffness, set, hollow, edge geometry, pivot, and the maker’s design.
In a design that uses curvature, the bow helps control the moving contact relationship as the blades close. It should not be evaluated separately from the rest of the blade geometry or from the exact pair’s condition and adjustment.
Excessive contact or set can make a pair feel stiff and may accelerate wear.
Insufficient or uneven contact can contribute to folding, pushing, or incomplete cutting, though edge condition, pivot adjustment, damage, and technique must also be checked.
Some Japanese makers describe hand setting or hammer adjustment as part of their own process. Others may use different tools and controls. Treat each process statement as maker-specific, and compare finished models through documented geometry, controlled inspection, and an appropriate trial.
Context and comparison
Blade curvature is established during manufacture and can be altered by damage, adjustment, or material removal during service. Inspection should compare the pair with its original geometry where that information is available. A qualified technician can assess contact, set, hollow, edge condition, pivot adjustment, and tip closure together before deciding whether corrective work is appropriate.
See Also
Sources
1 source- 🌐 HSC — Hairdressing Scissors Consortium (industry consortium)
Frequently Asked Questions
3 answers you can open one at a timeWhy does blade curvature matter?
In designs that use a lengthwise bow, curvature helps manage where the blades meet as they close. The intended amount is model-specific and works together with set, hollow, edge geometry, pivot adjustment, and blade stiffness. Use the maker’s specification rather than a universal measurement.
How is blade curvature created in traditional Japanese scissor making?
Some makers describe hand setting or hammer adjustment by an experienced craftsperson, while other production routes use fixtures, gauges, or controlled forming. Confirm the method for the exact maker and model; hand and machine processes are not performance grades by themselves.
What happens when curvature is too much or too little?
A curvature or set problem may contribute to excessive contact, uneven closure, folding, pushing, or poor tip performance. Those symptoms can also have other causes, so stop client use and have the exact pair inspected rather than diagnosing it from a universal curvature value.
Comments & questions
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