ScissorPedia

Blade Cross-Section Types

Understanding hamaguri-ba, dan-ba, and kenba as maker-used blade-section terms, separate from blade line and final edge grind.

Rows of unfinished metal blade blanks lie on a workshop floor beside a worker.
Photo: HONG SON on Pexels — Pexels License
Blade-geometry instrument

Record line, section, edge, and spatial curve independently

Japanese and maker vocabularies often distinguish these axes; no exhaustive national menu is assumed. Apply to Blade Cross-Section Types
SECTION ≠ EDGE
Plan-view line Each blade section Edge grind Spatial curve
  1. 01 Line Record plan-view curve, zones, radius basis, and blade length.
  2. 02 Section Describe the body profile and pairing of each blade half.
  3. 03 Edge Keep grind, finish, honing, and serration separate from section.
  4. 04 Spatial curve Name plane, direction, extent, and any vertical or whole-blade curve.

Do not inferHamaguri, sword, flat, convex, concave, or one R value cannot define every geometry axis or predict performance.

Four-axis geometry record · Section vocabulary

Read section terms from an end-on view

Hamaguri-ba, dan-ba, and ken-ba describe maker-used section ideas. None fills the other three geometry fields.

  1. 01 Side / plan view Open field

    Blade line

    Cross-section does not reveal the heel-to-tip blade line.

    Leave openStraightness, longitudinal curve, radius, and transition remain open.

    This route does not settle the field; record it separately.

  2. 02 End-on slice Source-scoped

    Cross-section

    The route groups rounded, stepped, and ridge-like section vocabulary.

    Leave openDimensions, symmetry, face count, ridge extent, and inner relief need model evidence.

    The route supports this vocabulary, within the cited source boundary.

  3. 03 Magnified working edge Open field

    Edge / grind

    The final edge can differ from the body section behind it.

    Leave openEdge planes, radius, finish, serration, condition, and service route remain open.

    This route does not settle the field; record it separately.

  4. 04 Declared axis + view Source-scoped

    Spatial curve

    The useful comparison view is an identified end-on slice.

    Leave openSlice position, orientation, scale, and whether one or both blades are shown must be declared.

    The route supports this vocabulary, within the cited source boundary.

Orientation aid—not a tracing template. Curves, planes, spacing, and proportions are deliberately non-dimensional.

  1. IdentityMaker + exact model

  2. EvidenceDated source + declared view

  3. Open fieldsKeep every unsupported detail unknown

Cross-section geometry describes the blade body behind the cutting edge when viewed end-on. Keep it separate from blade line (straight, willow, curved, and other longitudinal profiles) and edge grind (the final working surface at the edge). Makers sometimes layer these descriptions, so a sword-marketed blade may also carry a convex or flat edge.

Hamaguri-ba, dan-ba, and kenba are common Japanese trade terms, not a complete national standard. Their dimensions, pairings, and performance claims remain maker- and model-specific.

Three common terms

Reference table: Term, Usual description, Verify on the exact model
Term Usual description Verify on the exact model
蛤刃 Hamaguri-ba Clam-shell-like convex section Edge grind, hollowing, partner blade, and service route
段刃 Dan-ba Stepped or beveled section Number and angle of faces, edge finish, and partner blade
剣刃 Kenba Thicker ridge- or mountain-shaped sword section Which blade carries it, ridge extent, edge grind, dimensions, and mass

Why cross-section matters

Section geometry changes how much material supports the edge and how mass is distributed through the blade. It can therefore contribute to rigidity, balance, and how a service technician preserves the intended shape. It does not act alone: steel, heat treatment, blade line, edge grind, hollowing, set, tension, handle, and maintenance condition all affect the finished shear.

Cross-section alone does not establish maximum sharpness, a cutting-force multiplier, hair-damage risk, a resharpening-cycle count, or a required technique.

Comparing two models

  1. Confirm that both makers use the same measurement axis and term.
  2. Record which half carries each section and how the blade pair is described.
  3. Record the final edge grind separately.
  4. Compare published blade length, width, mass, balance, and intended use.
  5. Check the maker’s sharpening and service instructions.
  6. Trial the complete shear in the real task; do not rank an isolated section name.

Service implications

Sharpening should preserve the model’s intended edge and blade relationship. A hamaguri, dan, or ken label does not prove that an unspecified sharpener, flat stone, or convexing system is appropriate. Use the maker’s service route or a technician who can identify and preserve the exact construction.

Frequently asked questions

Is cross-section the same as edge type? No. Edge type describes the final sharpened surface, while cross-section describes the broader blade body behind it. They operate at different scales, and neither term supplies the other. Preserve the maker’s exact section and edge wording for the named model.

Can I change a scissor’s cross-section? Not practically. Cross-section is ground into the blade during manufacturing. Resharpening maintains it; it does not convert one profile into another.

Which cross-section is “best”? There is no universal best. Compare the complete model, the maker’s documented construction, fit and control in the intended task, and the available service route.

See Also

Best shears for beginners →

Source trail

Sources Reviewed

3 scoped sources behind this entry
  1. Secondary 🇯🇵 SisRma — Scissor Information Portal (industry reference)
  2. Secondary 🇯🇵 Scissors Yamato — Sharpening Specialist (specialist service)
  3. Primary 🇯🇵 Hikari Scissors — Official (manufacturer official)

Source scope and limitations are stated on the page. External links open in new tabs.

Quick clarifications

Frequently Asked Questions

3 answers you can open one at a time
What is the difference between the three Japanese cross-section profiles?

Hamaguri-ba describes a clam-shell-like convex section, dan-ba a stepped or beveled section, and kenba a thicker ridge- or mountain-shaped sword section. Makers use and combine these terms differently, so none supplies a universal sharpness, durability, technique, or hair-type ranking.

Is blade cross-section the same as edge type?

No. Edge type describes the final sharpened surface at the cutting edge, while cross-section describes the broader blade body behind it. The terms operate on different axes, and a section name does not establish one edge pairing or cutting result. Record the exact model’s section, edge, finish, partner blade, and maker-stated use separately.

Can a sharpener convert a scissor from one cross-section to another?

Cross-section is created during manufacture and should normally be preserved during service. A major regrind removes material and can change blade relationships, so it is not routine maintenance. Ask the maker or a sharpener qualified for the exact model before any geometry change.