用語 Reference

Glossary

Glossary of Nihonto Terminology

Name: Japanese Blades UK
Address: GB
Price range: £££

A working reference for terms used across the site — blade parts, surface activities, geometry, periods, mountings, and authentication papers. Maintained by Japanese Blades UK; corrections and additions welcomed.

Core terms

Nihonto 日本刀: Japanese sword in the strict sense — a blade forged by traditional methods from tamahagane, with a differentially hardened hamon produced by clay-coating and water quenching. Distinguished from shōwatō (machine-made WW2 swords); nihonto of all periods, from Heian tachi through modern gendaitō, share this fundamental method.
Tamahagane 玉鋼: Steel produced in the tatara smelter from iron sand and charcoal — the traditional raw material for nihonto forging. Quality varies by smelter and run; the smith selects and combines tamahagane pieces during the kawagane and shingane construction of the blade.

Blade parts

Kissaki 切先: The point section of the blade, bounded by the yokote line. Classified by size — ko-kissaki (small), chu-kissaki (medium), or o-kissaki (large) — and a primary indicator of period and school in kantei.
Yokote 横手: The line that delineates the kissaki from the rest of the blade. Its angle and sharpness are important kantei details.
Shinogi 鎬: The longitudinal ridge running along the blade that divides the flat ji from the upper bevel (shinogi-ji). Its height and placement affect both cutting geometry and visual character.
Ji 地: The flat surface of the blade between the shinogi and the hamon. The ji displays the hada (grain) and is where activities such as utsuri appear. See also: hada, utsuri.
Mune 棟: The spine (back) of the blade. Common forms are iori-mune (ridged), maru-mune (rounded), and kaku-mune (square); the profile is a useful indicator of school and period.
Hi 樋: A groove or channel cut into the blade, usually on the shinogi-ji. Beyond aesthetics, hi reduce weight and alter the blade's sound in motion. Also called bo-hi when a single full-length groove is present.
Hamachi 刃区: The notch at the base of the cutting edge that marks the boundary between the blade proper and the nakago. See also: munemachi.
Munemachi 棟区: The corresponding notch on the spine side, paired with the hamachi to seat the habaki. The distance between munemachi and hamachi can indicate whether a blade has been shortened (o-suriage).
Habaki 鎺: The metal collar that seats over the hamachi and munemachi, locking the blade snugly in the saya and providing a stop for the koiguchi. Usually copper or silver; quality and age of the habaki are secondary authentication details.
Nakago 茎: The tang — the unsharpened portion concealed within the tsuka. The nakago carries the smith's signature (mei), file marks (yasurime), and on WW2-era blades often a punched arsenal stamp. See also: mei, yasurime.
Mei 銘: The signature inscribed on the nakago, typically giving the smith's name on the omote (outward-facing side) and sometimes province, date, or dedication on the ura. Authenticity of the mei is the central concern of kantei and shinsa.
Yasurime 鑢目: The file-mark pattern on the nakago surface, applied to prevent slipping in the handle and to identify a smith or school. Common patterns include katte-sagari (slanting toward the edge), o-sujikai (steep diagonal), and kiri (horizontal).

Hada and hamon

Hada 肌: The grain pattern visible in the ji, produced by the folding and forging of the steel. Hada type is a primary characteristic used in school attribution. See also: itame, mokume, masame, muji.
Itame 板目: A wood-grain or burl-like hada pattern, the most common type. Ranges from fine (ko-itame) to coarse; associated with Bizen and Sōshū traditions among others.
Mokume 杢目: A rounded, figure-of-wood grain pattern reminiscent of bird's-eye maple, often appearing within or alongside itame. Associated with Yamashiro and some Bizen work.
Masame 柾目: A straight parallel grain, like quartersawn timber. Characteristic of the Yamato tradition and some Sōshū works; often confined to the shinogi-ji even when the ji shows another hada.
Muji 無地: An indistinct or nearly grain-free surface, typical of densely worked Sōshū steel and many Shintō-period blades. Not a flaw — in fine Sōshū work it accompanies rich nie activity.
Hamon 刃文: The temper line — the visible boundary between the hardened yakiba and the softer ji, produced by differential clay quenching (tsuchioki). Its shape, texture, and activities are the single most informative feature in kantei.
Suguha 直刃: A straight hamon, running parallel to the edge. The hallmark of the Yamato tradition and Rai smiths; ranges from narrow (hoso-suguha) to wide, with varying nie or nioi texture.
Gunome 互の目: A repeating, evenly spaced undulating hamon with rounded peaks. Common in Bizen work from the mid-Kotō period onward; often combined with choji or notare elements.
Notare 湾れ: A gently rolling, wave-like hamon. Associated with Sōshū and Shintō traditions; frequently appears in combination with other elements such as gunome (gunome-notare).
Choji 丁子: A hamon shaped in clove-like lobes, the signature of classic Ichimonji and Osafune Bizen work. Koshi-no-hiraita choji (open-waisted choji) is particularly prized and closely associated with the Fukuoka Ichimonji school.
Boshi 帽子: The continuation of the hamon within the kissaki, turning back toward the spine. Boshi form — ko-maru (small round turn), jizo, kaen (flame), or yakizume (running to the tip) — is a key school indicator.
Nie 沸: Individually visible martensite crystals in the hamon, appearing as bright, sandy or starry points. Heavy nie is the defining texture of Sōshū work and the smiths in its lineage. See also: nioi.
Nioi 匂: A fine, misty band of martensite visible as a diffuse glow rather than individual points — the characteristic texture of Bizen hamon. The distinction between nie and nioi is fundamental to period and school attribution.
Yakiba 焼刃: The hardened zone of the blade encompassing and surrounding the hamon. Its width, activities (ashi, yo, sunagashi, kinsuji, etc.), and boundary character are all read in kantei.
Utsuri 映り: A ghostly reflection or shadow appearing in the ji, parallel to the hamon. Most closely associated with Bizen blades — especially Ko-Bizen and Ichimonji — and its presence (or absence) is a significant authenticity and attribution indicator.

Geometry and dimensions

Nagasa 長さ: The cutting-edge length measured in a straight line from the hamachi to the tip of the kissaki. The standard reference measurement for classification: under approximately 30 cm for tantō, 30–60 cm for wakizashi, and over 60 cm for katana or tachi.
Sori 反り: The curvature of the blade, measured as the greatest perpendicular distance between the mune and a straight line from munemachi to tip. The position of deepest curve defines the sori type — see: tori-zori, koshi-zori, saki-zori.
Tori-zori 鳥反り: An even, full-length curvature with the deepest point near the centre of the blade. Typical of Kamakura-period tachi and the Bizen tradition.
Koshi-zori 腰反り: Curvature with the deepest point in the lower (koshi) third of the blade, near the hamachi. Characteristic of early Heian and Ko-Bizen tachi.
Saki-zori 先反り: Curvature concentrated toward the kissaki. Associated with naginata and some late-Kamakura/Nanbokuchō blades; appears again in the Shinshintō revival period.
Motohaba 元幅: The width of the blade measured at the hamachi. Together with sakihaba, motohaba determines the degree of fumbari and the visual taper of the blade.
Sakihaba 先幅: The width measured at the yokote, just below the kissaki. A narrow sakihaba relative to motohaba indicates strong fumbari; a wide sakihaba is associated with Nanbokuchō-period blades and some Shintō work.
Kasane 重ね: The thickness of the blade, usually measured at the mune above the hamachi (moto-kasane) and again near the yokote (saki-kasane). Kasane narrows considerably in Nanbokuchō-era works.
Fumbari 踏張: The pronounced taper from a wide motohaba to a narrower sakihaba, creating a characteristic flare at the base. Strong fumbari is a mark of Kotō tachi and an important indicator of age.

Types of swords

Tachi 太刀: A long curved sword worn suspended edge-downward from the belt (obi), prevalent from the Heian through Muromachi periods. Generally longer and with more curvature than the katana; signed on the side that faces outward when worn (ura).
Katana 刀: The classic long sword of the samurai, worn edge-upward through the obi, dominant from the Muromachi period onward. Nagasa typically 60–75 cm; the omote (outward face when worn) is the opposite side to tachi convention.
Wakizashi 脇差: The shorter companion sword of the daisho pairing, with nagasa broadly between 30 and 60 cm. Worn alongside the katana by samurai from the Edo period; independently useful in confined spaces and for the ritual of seppuku.
Tantō 短刀: A single-edged blade under approximately 30 cm nagasa. Made from the Heian period onward; Kamakura-period tantō by Masamune, Yoshimitsu, and their contemporaries represent some of the highest achievements in the form.
Ōdachi 大太刀: An exceptionally long tachi, sometimes exceeding 90 cm or considerably more, associated with the Nanbokuchō period (14th century). Many surviving ōdachi were later shortened (o-suriage) to more practical lengths.
Naginata 薙刀: A polearm with a curved single-edged blade mounted on a long shaft. Widely used by infantry and warrior monks; naginata-naoshi refers to blades shortened and remounted as conventional swords, identifiable by their distinctive saki-zori and wide body.
Yari 槍: A spear blade, double-edged and typically diamond-section, mounted on a long pole. Unlike naginata, yari blades are straight; they are signed on the nakago and collected as nihonto in their own right.
Kaiken 懐剣: A small dagger worn concealed in the breast of the kimono, typically by women of samurai class. Usually mounted in elegant koshirae with matching lacquerwork; nagasa rarely exceeds 20 cm.

Periods

Jōkotō 上古刀: Blades predating the curved nihonto form, broadly before the late Heian period (pre-c. 900 AD). Straight double-edged forms; survivals are extremely rare and largely held in shrines or museums.
Kotō 古刀: The "old sword" period, c. 900–1596. Encompasses the great classical schools — Ko-Bizen, Yamashiro, Sōshū, Mino — and the full arc from early tachi through the Sengoku era. Generally considered the peak of Japanese swordsmithing.
Shintō 新刀: The "new sword" period, c. 1596–1780. Swordsmiths relocated to castle towns; production became more commercial. Technically accomplished but scholarly opinion generally ranks shintō below the finest kotō work.
Shinshintō 新々刀: The "new-new sword" period, c. 1780–1876, marked by a deliberate revival of Kotō techniques led by smiths such as Suishinshi Masahide and Taikei Naotane. Ended with the Haitōrei edict of 1876, which prohibited the wearing of swords.
Gendaitō 現代刀: Modern swords made from 1876 to the present by traditionally trained smiths using tamahagane and classical methods. The NBTHK recognises gendaitō as legitimate nihonto eligible for shinsa and preservation papers.
Shōwatō 昭和刀: Military blades of the Shōwa era (1926–1945) produced by machine or semi-industrial methods, not by licensed traditional smiths. Shōwatō are ineligible for NBTHK papers and are not classified as nihonto, though they are collectable as militaria in their own right.

Mountings

Koshirae 拵: The complete set of furniture and fittings for a mounted sword — tsuka, saya, tsuba, and all associated metalwork. A blade may have multiple historic koshirae; quality koshirae by named craftsmen are collected independently of the blade.
Shirasaya 白鞘: A plain, undecorated storage mounting of untreated wood (usually honoki magnolia), fitted precisely to the blade for long-term preservation. The presence of a shirasaya does not imply a blade lacks koshirae — blades are routinely stored in shirasaya between exhibitions.
Tsuka 柄: The handle, constructed over a wooden core (tsuka-gi) wrapped in samegawa and then bound with tsuka-ito in a traditional lozenge pattern. The tsuka houses the mekugi peg that secures the nakago.
Saya 鞘: The scabbard, traditionally of honoki wood lacquered in a variety of styles. The saya includes the koiguchi (mouth), kurikata (cord knob), and kojiri (chape).
Tsuba 鍔: The hand-guard, separating blade from handle. Made in iron, shakudō, shibuichi, or brass; decorated by named schools — Goto, Myochin, Shoami — whose work is collected as fine metalwork in its own right.
Fuchi 縁: The collar fitting at the blade end of the tsuka, forming one half of the fuchi-kashira set. Usually made and signed as a matched pair with the kashira.
Kashira 頭: The cap at the butt end of the tsuka, paired with the fuchi. Matching fuchi-kashira sets in shakudō with gold nunome-zogan are among the most desirable koshirae components.
Menuki 目貫: Small decorative ornaments set beneath the tsuka-ito on either side of the handle, originally placed over the mekugi hole. Usually figural — dragons, shishi, blossoms — and closely associated with the Goto school of metalworkers.
Samegawa 鮫皮: Ray skin (technically from the ray Dasyatis akajei) used to wrap the tsuka-gi beneath the ito binding. The pebbly surface provides grip and a traditional aesthetic; quality samegawa with large, regular nodes is preferred.
Tsuka-ito 柄糸: The braid or cord wrapped over the samegawa in a lozenge (hishi-gumi) or other pattern to form the finished grip. Silk is traditional; cotton common on military-grade mounts. Colour and pattern vary by period and school.
Kurikata 栗形: The knob on the saya through which the sageo is threaded. Its position on the saya and material (horn, ivory, lacquered wood, metal) reflect the formality of the mounting.
Sageo 下緒: The cord threaded through the kurikata, used to secure the saya to the obi or tie the sleeve during combat. Silk sageo in various colours and braids are associated with particular ranks and ceremonial contexts.
Kojiri 鐺: The chape or end cap of the saya, protecting the tip. On formal koshirae these are often of matching metalwork; on shirasaya and military scabbards a simple horn or steel fitting is typical.
Kyū Guntō 旧軍刀: The "old army sword" pattern adopted c. 1875–1934: a Western-influenced cavalry sabre mounting used by Meiji and early Shōwa officers. Blades ranged from imported European sabres to remounted nihonto; now largely supplanted in collector interest by later patterns.
Shin Guntō 新軍刀: The "new army sword" introduced in 1934 for Imperial Japanese Army officers, deliberately echoing the classical tachi in its traditional brown ito-wrapped tsuka and cherry-blossom menuki. The most commonly encountered WW2 Japanese sword mounting. Blades may be nihonto (traditionally made) or shōwatō (machine-made).
Kai Guntō 海軍刀: The Imperial Japanese Navy officer's sword, distinct from the Shin Guntō in its black same-wrapped tsuka and different furniture style. Often mistaken for the army pattern; the navy anchor mon on fittings is the clearest identifier.
Type 95 NCO Sword: The standard-issue sword for Imperial Japanese Army non-commissioned officers, produced 1935–1945. Fully machine-made with a cast aluminium or zinc alloy tsuba and a non-removable blade; not a nihonto. Collectable as militaria; ineligible for NBTHK papers.
RJT — Rikugun Jumei Tōshō 陸軍受命刀匠: Army-Appointed Swordsmith — a designation granted by the Imperial Japanese Army to traditionally trained smiths authorised to produce blades for military officers. RJT-stamped blades are genuine nihonto, traditionally made from tamahagane, and are eligible for NBTHK papers. The stamp (usually on the nakago) is an important authentication detail for WW2-period blades.

Papers and authentication

NBTHK 日本美術刀剣保存協会: Nihon Bijutsu Token Hozon Kyokai — the Society for the Preservation of Japanese Art Swords, founded 1948. The principal authentication body; NBTHK papers (origami) are the international standard for nihonto authentication and are essential for export from Japan under cultural property law.
NTHK 日本刀装具保存会: Nihon Token Hozon Kai — an independent authentication society offering an alternative to NBTHK papers. NTHK papers are respected within the collecting community but generally considered secondary to NBTHK for high-value transactions.
Kantei 鑑定: The structured discipline of examining and attributing a nihonto blade by physical evidence — sugata, hada, hamon, boshi, and nakago — rather than by signature alone. Not a guess; a reasoned argument from observable characteristics against accumulated school and period reference material. The intellectual foundation beneath every NBTHK attribution.
Shinsa 審査: The formal examination process conducted by NBTHK or NTHK judges, at which blades are assessed for authenticity, attribution, and quality. Shinsa sessions are held in Japan and at major overseas events; submission requires the blade to be present.
Hozon 保存: The entry-level NBTHK preservation certificate, confirming that a blade is a genuine nihonto worthy of preservation. The baseline standard for any serious transaction; a blade without at least Hozon papers carries meaningful attribution risk.
Tokubetsu Hozon 特別保存: NBTHK "Specially Preserved" — the second tier, awarded to blades of superior quality and condition above the Hozon standard. A Tokubetsu Hozon paper significantly affects value and is the typical threshold for mid-to-high market pieces.
Jūyō 重要: NBTHK "Important" — the third and highly selective tier, awarded to blades of outstanding historical or artistic significance. Jūyō papers represent a major distinction; fewer than a few thousand blades hold this status. Substantially affects both value and export eligibility.
Tokubetsu Jūyō 特別重要: NBTHK "Specially Important" — the highest tier of NBTHK certification, reserved for blades of exceptional national importance. Fewer than 1,000 blades hold this designation; most are held in institutional or major private collections.
Origami 折り紙: Literally "folded paper" — the informal term for any NBTHK authentication certificate, derived from the traditional practice of folding the document. In the trade, "it has origami" means a blade carries valid NBTHK papers; always verify the certificate number against NBTHK records when purchasing.

Armour and fittings

Yoroi 鎧: Japanese armour in the broad sense — the full set of defensive equipment worn by a samurai. Encompasses kabuto, dō, kote, haidate, and suneate; the term is used both specifically for the laced ōyoroi of the Heian period and generally for all forms of Japanese armour.
Kabuto 兜: The samurai helmet, consisting of the iron bowl (hachi) and its attached neck-guard (shikoro). Kabuto were produced by named armourers and regional schools across several centuries; surviving examples are dated and attributed primarily by construction method, lacquer style, and regional tradition.
Hachi 鉢: The iron bowl of the kabuto — the main dome-shaped skull piece to which the shikoro, fukigaeshi, and maedate fittings are attached. Construction details of the hachi — the number of plates, riveting pattern, and lacquer treatment — are primary evidence in dating and attributing a helmet.
Shikoro 錏: The neck-guard of the kabuto, composed of lamellar plates suspended from the lower rim of the hachi and flaring outward to protect the neck and upper shoulders. Lacing colour and plate construction reflect the period and regional tradition of the armour.
Fukigaeshi 吹返: The wing-like side-pieces of the shikoro that are turned back and upward at the front of the kabuto to protect the face and prevent a sword from sliding down into the neck. Their shape and decoration are a useful regional and period indicator.
Tehen 天辺: The small opening or ring at the crown of the kabuto hachi, originally left to accommodate the topknot. The tehen fitting is usually a decorative metal ring; its condition and style are minor but useful dating details.
Maedate 前立: The crest ornament mounted at the front of the kabuto, ranging from simple geometric forms to elaborate sculptural pieces depicting dragons, shishi, or Buddhist iconography. Maedate are frequently missing on antique helmets that passed into storage; their absence is common and does not imply damage.
Menpo 面頬: Face armour worn with the kabuto, in several forms covering different amounts of the face. The most common types are the hanbo (lower half), hoate (cheeks and chin only), and sōmen (full face). Menpo typically incorporate nose pieces, lacing for the yodare-kake, and attachment cords to secure the piece under the kabuto.
Hanbo 半頬: A menpo covering the lower half of the face — roughly from the nose downward — the most commonly produced and surviving form across the Edo period. Often fitted with a detachable nose piece and the yodare-kake throat plates.
Hoate 頬当: A minimalist menpo covering only the cheeks and chin, leaving the nose exposed. Lighter than the hanbo and associated with periods or contexts favouring mobility over full protection.
Sōmen 総面: A full-face menpo mask covering the entire face including forehead and nose. Less common than hanbo forms; elaborate sōmen with sculpted or grimacing expressions were produced as ceremonial and display pieces in the Edo period.
Yodare-kake 垂掛: The lamellar throat-guard plates suspended from the lower edge of the menpo, protecting the neck and throat. Their presence and articulation confirm a menpo is substantially intact; missing yodare-kake are a common condition issue.
Dō 胴: The cuirass — the armoured section covering the torso. Dō construction varied significantly by period and region: okegawa-dō (horizontal-plate) and tosei-dō (five-plate) forms are common in Edo-period armour; the distinctive Sendai-dō of the Date-clan domain is a regionally significant variant. See also: sendai-do.
Sendai-dō 仙台胴: A cuirass form associated with the Date-clan domain at Sendai — characterised by horizontal plate construction with a restrained dark lacquer finish, reflecting the aesthetic of Tōhoku armour more broadly. A Sendai-dō in situ is one of the clearest regional identifiers for northern Edo-period armour.
Myōchin school 明珍: The dominant lineage of Japanese armour smiths, tracing a claimed ancestry back to the Heian period and producing helmets and armour fittings across many centuries. By the Edo period, Myōchin smiths were active across Japan; the name became both a school designation and, in some cases, a prestige attribution applied loosely to unsigned work. Major centres included Kyoto and Edo.