Nakago: The Hidden Record of Katana History

The Nakago represents far more than the katana's structural tang—it serves as the blade's historical record, authentication document, and construction foundation. Hidden beneath the handle (Tsuka), this unpolished extension preserves the swordsmith's signature (Mei), file mark patterns (Yasurime), ownership records, and surface patina that collectively tell the blade's complete story. Master appraisers spend more time examining Nakago than any other blade feature, as this hidden section reveals authenticity, age, maker, and structural integrity that determine a sword's true value and identity.

What is the Nakago?

Nakago (茎) refers to the unpolished tang extension that continues from the blade into the handle. This hidden section—typically 9-12 inches on katana—provides the structural foundation anchoring the blade securely while serving as the historical record documenting the sword's lineage.

The Nakago's functions include:

Structural foundation: Transfers cutting forces from blade to handle without failure Historical documentation: Preserves smith's signature, dates, and ownership records Authentication evidence: File marks, patina, and alterations reveal authenticity and age Balance adjustment: Tang length and shape affect the sword's overall balance point Preservation: The unpolished surface naturally develops protective patina preventing rust

Quality Nakago construction separates authentic swords from dangerous replicas. Proper tang geometry, dimensions, and construction ensure forces transfer safely during cutting without catastrophic failure.

Nakago Anatomy

The tang features multiple distinct elements, each providing valuable information:

Mei (銘) - Signature

The smith's signature inscribed (chiseled) into the tang surface, typically on the side facing outward when worn. Mei provides crucial authentication evidence and identifies the maker. Signatures range from simple names to elaborate inscriptions including:

Smith's name: The maker's given name or art name
Location: The province or city where forged
Date: Era name and year of creation
Honorifics: Titles or designations earned by the smith
Ownership records: Later additions by subsequent owners

Mei placement: Traditionally appears on the Omote (outward-facing side when worn edge-down). The inscription's style, chisel work quality, and character formation help authenticate attributions.

Yasurime (鑢目) - File Marks

The file mark pattern visible on the Nakago surface from the final shaping process. These aren't random scratches—they follow deliberate patterns that vary by school, region, and period. Common Yasurime styles include:

Kiri (切) - Straight horizontal: Simple horizontal lines perpendicular to the blade. Common on many periods and schools. Clean, workmanlike appearance.

Katte-sagari (勝手下り) - Slanting toward edge: Diagonal lines slanting from spine toward edge. Associated with certain Bizen and Mino school smiths. Creates dynamic visual flow.

Higaki (檜垣) - Cypress fence pattern: Intersecting diagonal lines creating diamond or lattice patterns. Associated with some Soshu school masters. Complex, decorative appearance.

Sujikai (筋違) - Diagonal crossing: Bold diagonal lines crossing at angles. Appears on some Yamashiro province blades. Distinctive, easily recognized pattern.

O-sujikai (大筋違) - Large diagonal: Pronounced, widely-spaced diagonal marks. Creates bold, martial appearance. Less common than standard patterns.

Yasurime patterns help attribute unsigned blades to specific schools or regions. Combined with other evidence, file marks provide crucial authentication clues.

Mekugi-ana (目釘穴) - Peg Holes

The holes through which bamboo pegs (Mekugi) pass to secure the handle. Original blades typically feature one or two holes. Additional holes indicate the blade was remounted multiple times throughout history—each remounting potentially requiring new hole placement as handle length or construction changed.

Authentication significance: Multiple holes provide age evidence (more remountings = older blade). Hole placement and condition reveal handling history. Modern holes in supposedly ancient tangs suggest forgery.

Mune-machi (棟区) and Ha-machi (刃区)

The notches where the tang meets the blade at the spine (Mune-machi) and edge (Ha-machi). These critical junctures define where the polished blade ends and unpolished tang begins. The Habaki collar seats against these notches.

Condition importance: Wear, damage, or alterations at these points indicate blade shortening (suriage) or other modifications that significantly affect value and authenticity assessment.

Yasuri-me (鑢目) - File Pattern Surface

The overall tang surface showing file mark patterns, texture, and finish. This surface naturally develops protective patina (rust) over decades and centuries—a crucial authentication marker impossible to replicate convincingly on new blades.

Nakago Patina (Sabi) and Age Assessment

The Nakago's surface patina provides crucial age and authenticity evidence:

Natural Patina Development

Unpolished iron and steel naturally oxidize, developing characteristic rust patina (sabi) over time. This patina forms in layers, creating:

Color progression: New tangs appear bright metallic gray. Over decades, they develop brown, then dark brown, eventually achieving deep black patina after centuries. Color depth and uniformity indicate age.

Texture development: Ancient patina becomes smooth and dense, almost enamel-like. Fresh rust appears powdery and loose. The texture difference is immediately apparent to experienced appraisers.

Layer accumulation: Centuries-old patina builds microscopic layers impossible to replicate quickly. Cross-sectional examination reveals stratification indicating genuine age.

Fake Patina Detection

Forgers attempt to age new tangs artificially through various chemical and physical treatments. However, artificial aging creates telltale signs:

Uniform coloration lacking natural variation
Loose, powdery texture rather than dense, smooth finish
Chemical residues or unusual coloring
Inconsistent patina depth across the surface
Absence of appropriate wear patterns

Experienced appraisers identify fake patina immediately through visual inspection and sometimes chemical analysis.

Full Tang vs. Rat-Tail Construction

Tang construction quality separates functional swords from dangerous decorative replicas:

Full Tang (Traditional Japanese Construction)

Authentic katana feature full tangs where the blade steel continues as a solid extension into the handle. The Nakago comprises the same steel as the blade, forged as one continuous piece. This construction:

Structural integrity: Forces transfer through solid steel from blade to handle without weak points Safety: Properly constructed full tangs never fail during normal use Authenticity: All historical Japanese swords use full tang construction Balance: The tang's mass contributes to overall sword balance

The tang's width typically measures 25-35mm at the Habaki, tapering toward the Kashira pommel. Thickness ranges from 6-10mm depending on blade size and period.

Rat-Tail Tang (Dangerous Replica Construction)

Many cheap replicas use "rat-tail" construction where a narrow threaded rod extends from a partial blade into the handle. This rod attaches via welding, threading, or other mechanical means. Rat-tail construction:

Structural weakness: The junction between blade and rod creates a critical weak point prone to catastrophic failure Safety hazard: Rat-tail tangs can snap during use, sending the blade flying—potentially fatal Inauthenticity: No historical Japanese swords use this construction method Value indicator: Rat-tail construction indicates the cheapest quality reproductions

Critical warning: Never use rat-tail constructed swords for cutting practice or martial arts. The failure risk is unacceptable. Stick-tang swords belong on walls only, never in hands during practice.

Nakago Alterations and What They Reveal

The Nakago often shows modifications revealing the blade's history:

Suriage (磨上げ) - Shortening

When blades are shortened (cutting the Nakago), smiths or polishers remove the original tang section. This:

Removes signatures: Original Mei is often lost when tangs are cut Creates attribution challenges: Unsigned shortened blades are harder to authenticate Affects value: Suriage typically reduces value significantly, though some historic reasons for shortening exist Reveals remounting: New Mekugi-ana and altered tang shapes indicate remounting after shortening

Gimei (偽銘) - False Signatures

Unscrupulous dealers sometimes add false signatures to unsigned blades or alter existing signatures to attribute blades to famous makers. Detection requires:

Chisel work quality analysis
Character style examination
Signature placement appropriateness
Overall blade quality vs. attributed maker's standards
Patina analysis around inscription

Additional Inscriptions

Later owners sometimes added inscriptions documenting:

Ownership transfers
Testing results (tameshigiri)
Repair dates
Awards or designations

These secondary inscriptions provide valuable historical context when authentic.

Historical Evolution of Nakago Styles

Koto Period (Ancient Swords, Pre-1596)

Early Nakago featured relatively simple file patterns and straightforward signatures. Tang shapes varied by school but typically showed graceful, functional proportions. Original koto tangs with undisturbed patina command premium prices.

Shinto Period (New Swords, 1596-1780)

Post-unification smiths developed more elaborate Yasurime patterns and detailed Mei inscriptions. Signatures often included locations, dates, and honorifics. Tang proportions standardized somewhat compared to earlier variety.

Shinshinto Period (New-New Swords, 1781-1876)

Late Edo period smiths created particularly refined Nakago with elegant file patterns and carefully executed signatures. This period saw increased attention to tang aesthetics alongside blade quality.

Modern Period (1876-Present)

Contemporary smiths continue traditional Nakago construction and inscription methods. Modern Mei often includes more detailed information and registration numbers required by law.

Nakago Condition and Value Impact

Tang condition significantly affects blade value and collectibility:

Excellent condition: Original, unaltered Nakago with clear Mei, appropriate patina, and minimal wear commands premium prices. Collectors prioritize original tangs.

Good condition: Some wear, additional Mekugi-ana, or minor alterations are acceptable for functional swords. Moderate value impact.

Poor condition: Heavy damage, suriage (shortening) removing signatures, gimei (fake signatures), or suspicious patina dramatically reduce value. Authentication becomes difficult or impossible.

Restored/cleaned: Improperly cleaned or restored tangs lose critical patina evidence. This severely impacts collectible value even if the blade itself is excellent.

Authentication Best Practices

When evaluating Nakago for authenticity:

Examine patina: Natural patina shows consistent aging, appropriate coloration, smooth texture, and stratification under magnification

Study Mei carefully: Compare signature style, chisel work, and character formation against known examples from the attributed smith

Analyze Yasurime: Verify file patterns match expected styles for the attributed school, region, and period

Check Mekugi-ana: Assess hole quantity, placement, and condition for historical appropriateness

Evaluate proportions: Tang dimensions, shape, and taper should suit the blade's size and purported period

Seek expert opinion: Professional authentication by recognized authorities remains essential for valuable blades

Frequently Asked Questions

What does Nakago mean in English? Nakago (茎) translates to "tang" or "hilt," referring to the unpolished blade extension that inserts into the handle. This section serves as both structural foundation and historical record.

Why is the Nakago left unpolished? The unpolished surface naturally develops protective patina preventing rust while preserving signatures, file marks, and other authentication evidence. Polishing would remove these crucial historical and structural details.

What is Mei? Mei (銘) refers to the smith's signature inscribed into the Nakago. This inscription identifies the maker and often includes location, date, and other details crucial for authentication and historical documentation.

What are Yasurime file marks? Yasurime (鑢目) are deliberate file mark patterns on the tang surface created during final shaping. Different schools and regions used distinctive patterns (Kiri, Katte-sagari, Higaki) that help attribute and authenticate blades.

How can you tell if a Nakago signature is authentic? Authentic Mei display appropriate chisel work quality, correct character styles for the period, proper placement, consistent patina, and overall blade quality matching the attributed smith's standards. Expert authentication is essential for valuable attributions.

What is rat-tail tang construction? Rat-tail describes dangerous replica construction where a narrow threaded rod extends from a partial blade. This creates catastrophic failure risk. All authentic Japanese swords use full tang construction where blade steel continues as one solid piece.

Why do some Nakago have multiple peg holes? Multiple Mekugi-ana indicate the blade was remounted several times throughout history, with each remounting potentially requiring new hole placement. More holes generally indicate greater age and extensive handling history.

Does Nakago condition affect blade value? Absolutely. Original, unaltered tangs with clear signatures and appropriate patina command premium prices. Shortening (suriage), fake signatures (gimei), improper cleaning, or damage dramatically reduce value and complicate authentication.