A brief, unhurried introduction to the vocabulary of Japanese swords and fittings — for the newcomer and the returning visitor alike.
Nihonto — literally "sword of Japan" — refers to blades forged using the traditional tamahagane steel smelting process, a method unchanged for over a thousand years. The blade is not merely a weapon; it is considered the soul of the samurai, a living document of its maker's mastery.
The curve (sori), the grain of the steel (hada), and the crystalline temper line (hamon) are each read as a kind of calligraphy. No two blades are identical.
Tachi 太刀
Long cavalry sword worn edge-down, suspended from the belt. Pre-Edo, deeply curved. Typically over 60 cm.
Katana 刀
The iconic samurai sword worn edge-up through the sash (obi). The defining blade of the Edo period. 60–75 cm.
Wakizashi 脇差
Shorter companion blade (30–60 cm). Worn paired with the katana as the daisho — the mark of a samurai.
Tanto 短刀
Dagger under 30 cm. Often the finest canvas for a smith's technical mastery — small scale amplifies every detail.
Naginata 薙刀
Curved polearm blade. Closely associated with female warriors and Buddhist monks. Dramatic swept shape.
Yari 槍
Spear blade. Straight or cross-shaped. Forged with the same care as a sword blade.
Nagasa 長さ
The measured length of the blade from tip to the base of the tang. The primary dimension defining blade type.
Sori 反り
The curvature of the blade. Its degree, placement, and origin point are diagnostic of period and school.
Kissaki 切先
The tip of the blade. Size and shape — ko-kissaki (small), chu-kissaki (medium), o-kissaki (large) — are critical to assessment.
Yokote 横手
The line separating the blade body from the kissaki. A crisp, straight yokote indicates high-quality forging.
Hada 肌
The grain pattern of the steel, visible on the blade surface. Itame (wood-burl), masame (straight), mokume (wood-eye), and others — each is a school fingerprint.
Hamon 刃文
The temper line — the crystalline boundary between hardened edge (ha) and softer spine (mune). Straight (suguha), wavy (notare), irregular (gunome, choji) — endlessly varied.
Nie / Nioi 沸・匂
The texture of the hamon. Nie: individual crystals visible to the naked eye, coarse and brilliant. Nioi: mist-like granular boundary, refined and soft.
Nakago 茎
The tang — the unpolished portion of the blade hidden inside the handle. Bears the smith's signature (mei) and is never cleaned or altered.
Mune 棟
The spine of the blade, opposite the cutting edge. Its cross-sectional shape (iori-mune, maru-mune, kaku-mune) varies by school and period.
Ji 地
The flat body of the blade between the hamon and the shinogi (ridge line). Where hada is most visible.
Shinogi 鎬
The longitudinal ridge line running the length of the blade, dividing ji from shinogiji (the upper flat above the ridge).
Boshi 帽子
The hamon as it enters the kissaki. Its form — komaru (rounded), kaen (flame-like), hakikake (brushed) — is one of the most telling diagnostic features.
Utsuri 映り
A ghostly shadow-reflection of the hamon in the ji. Characteristic of certain Bizen-den blades; considered a mark of the highest forging.
Funbari 踏張り
The widening of the blade at the base (hamachi/machi) relative to the tip. A pronounced funbari signals an older or ubu (unshortened) blade.
Hiraniku 平肉
The fullness or convexity of the blade's flat. A thick hiraniku indicates robust construction; thin or hollow is considered weaker.
Daisho 大小
The paired long-short set of katana and wakizashi. Exclusively the privilege of the samurai class.
Quick-reference vocabulary — nihonto & tosogu
Bo-hi
棒樋
A single, wide groove running along the blade to reduce weight while maintaining structural integrity.
Boshi
帽子
The temper line (hamon) as it curves around the tip (kissaki) of the blade.
Daisho
大小
A matched pair of long and short swords — katana and wakizashi — worn together by samurai.
Funbari
踏張
The degree of taper from the base (machi) to the tip — a mark of early blade styles.
Ha
刃
The cutting edge of the blade. Also used to denote a school or lineage (派).
Hada
肌
The grain pattern of the steel, created through repeated folding and forging. Types include itame, mokume, masame, and ayasugi.
Hamon
刃文
The temper line — the boundary between the hardened edge and the body of the blade. A primary aesthetic and identification feature.
Horimono
彫物
Decorative carvings on the blade — Sanskrit characters, dragons, Buddhist deities, or grooves.
Itame
板目
A wood-grain hada pattern, resembling the cross-section of planked timber. Common in many traditions.
Kantei
鑑定
Connoisseurship — the scholarly practice of attributing and appraising a blade by its physical characteristics.
Kissaki
切先
The tip of the blade. Its shape and size are key period indicators — small (ko), medium (chu), large (o).
Masame
柾目
A straight, parallel-grain hada resembling quartersawn timber. Associated with Yamato tradition.
Mei
銘
The smith's signature, carved into the tang (nakago) of the blade. Reading mei is a specialized discipline.
Mokume
木目
A burl-wood grain hada pattern with rounded, overlapping shapes. Common in Soshu tradition.
Mumei
無銘
Unsigned. Many great blades carry no mei — attribution becomes scholarly work based on style alone.
Nagasa
長さ
The cutting-edge length of the blade, measured from the machi notch to the tip.
Nakago
茎
The tang — the unsharpened portion of the blade that fits inside the handle. Bears the mei.
NBTHK
日本美術刀剣保存協会
Nihon Bijutsu Token Hozon Kyokai — Japan's foremost sword preservation society. Issues Hozon, Tokubetsu Hozon, and Juyo certificates.
Nie
沸
Bright, granular crystalline formations in the hamon. Visible as individual sparkling points.
Nioi
匂
A misty, diffuse temper boundary composed of very fine nie, visible as a glowing line.
Nihonto
日本刀
A sword of Japan — forged using the traditional tamahagane process. Encompasses tachi, katana, wakizashi, tanto, and others.
NTHK
日本刀保存会
Nihon Token Hozon Kai — an alternative certification body, highly respected internationally.
Origami
折紙
Historical appraisal documents issued by pre-modern connoisseurs. The pre-modern equivalent of modern certificates.
Shinogi
鎬
The lateral ridge running along the blade, separating the flat (ji) from the bevel (shinogi-ji).
Sori
反り
The curvature of the blade. Its degree and position (tori-zori, koshi-zori, etc.) are period markers.
Sugata
姿
The overall shape or silhouette of the blade — the first element examined in kantei.
Tamahagane
玉鋼
The steel produced in the traditional Japanese smelting furnace (tatara). The raw material of all nihonto.
Tanto
短刀
A dagger with blade under 30 cm. Often the finest showcase for a smith's hamon artistry.
Wakizashi
脇差
The shorter companion blade worn with the katana. Together they form the daisho.
Yakiba
焼刃
The hardened zone of the blade — the hamon and everything within it toward the edge.
Fuchi-Kashira
縁頭
The collar (fuchi) and pommel cap (kashira) at either end of the sword handle.
Habaki
鎺
The metal collar that fits snugly over the base of the blade and holds it in the scabbard.
Kogai
笄
A skewer-like implement carried in a pocket of the scabbard, used for grooming.
Kojiri
鐺
The metal cap at the bottom of the scabbard (saya).
Koshirae
拵
The complete dressed mounting of a sword — scabbard, handle, fittings, and all ornamental elements unified.
Kozuka
小柄
The handle of a small utility knife (ko-gatana) carried in the scabbard pocket.
Menuki
目貫
Small decorative ornaments seated beneath the handle wrapping (ito), originally functional pegs.
Saya
鞘
The scabbard. Usually lacquered wood, often carrying its own artistic program.
Tosogu
刀装具
The collective term for sword fittings — tsuba, fuchi-kashira, menuki, kozuka, kogai, habaki, and kojiri.
Tsuba
鍔
The handguard. Positioned between blade and handle. One of the most collected objects in Japanese art.
Tsuka
柄
The handle. Constructed of wood, covered in ray skin (same), and wrapped in silk braid (ito).