Blade Terminology

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Glossary Termsort icon Definition
fukura

The cutting edge of the kissaki. Also, the curvature of the kissaki. It can be described as rounded or not rounded.

gaku-mei
額銘

A way to preserve mei (signature) on the tang when shortening it (see o-suriage) by cutting it off the original position and reattaching it to the altered nakago.

ha

A tempered cutting edge of a blade.

ha-watari
刃渡り

See nagasa.

hamachi
刃区

A notch on the blade side. See machi.

hamon
刃文

A distinct temper line between areas of softer (ji) and harder (ha) steel along the edge of the blade.

See Hamon Types for more details.

hataraki
働き

Various activities, distinctive features of the steel seen inside the hamon and ji, created during the hardening process.

See hataraki in hamon and hataraki in jihada for an overview of different types of activity.

hi

Hi is a groove engraved along the blade on the shinogi-ji or hira-ji area. Originally the main purpose of these grooves was to reduce the blade's weight and improve its cutting ability. Later grooves served as a decoration or even as a way to conceal flaws.

Grooves are classified according to shape and location with terms describing the top of the groove ending with -hi (樋, usually pronounced as -bi when preceded by other characters) or -tome (止め) for features at the bottom of the groove (known as tome).

Hi

  • bo-bi: A continuous straight groove of notable width, known as katana-bi on tantō. With soe-bi, a secondary narrow groove follows the inner straight length of the main one. With tsure-bi, the secondary is similar but continues beyond the straight length.
  • kage-bi: A small groove beside a regular groove of a blade. Yamanaka mentions that this was an old term for soe-bi.
  • futasuji-bi: Two parallel grooves.
  • shobu-bi: A groove shaped like the leaf of an iris plant.
  • naginata-bi: A miniature bo-bi whose top is oriented opposite from the blade's, and usually accompanied by a soe-bi. Seen primarily on naginatas.
  • kuichigai-bi: Two thin grooves that run the top half of the blade; the bottom half is denoted by the outer groove stopping halfway while the inner one expands to fill the width.
  • koshi-bi: A short rounded-top groove found near the bottom of a blade, near to the tang.

Tome

  • kaki-toshi: The groove runs all the way down to the end of the tang.
  • kaki-nagashi: The groove tapers to a pointed end halfway down the tang.
  • kaku-dome: The groove stops as a square end within 3 cm of the tang's upper end.
  • maru-dome: Similar to the kaku, except with a rounded-end.
ji

A surface between the shinogi and the hamon. See also: jihada, jigane, hira.

jōsun
定寸

The Tokugawa Shogunate standardized the size of swords in Japan during the Edo period to what is commonly called jōsun length. For katana jōsun is 2 shaku 3 sun 5 bu (71.21cm), for tantō - 8 sun 5 bu (25.76cm).

Tantō longer than jōsun are called sunnobi-tantō 寸延び短刀, and less than jōsun sunzumari-tantō 寸詰まり短刀. There was no standard length for wakizashi, but those over 1 shaku 8 Sun (54.5 cm) are called ō-wakizashi 大脇指. Tachi 太刀 of more than 3 Shaku (90.9 cm) are referred to as ōdachi 大太刀, whereas tachi under 2 shaku (60.6 cm) are called Kodachi 小太刀.

Source

kage-bi
影樋

A small groove beside a regular groove of a blade. Yamanaka mentions that this was an old term for soe-bi.

kasane
重ね

Thickness of the blade. See also: moto-kasane, saki-kasane.

ken

Double-edged straight sword. Ken form is most commonly seen in tanto, but longer kens also exist.

kengyo
剣形

'Sword-shaped'. Shape of the nakagojiri with two straight lines coming to a point in the center at around 90 degree angle.

It is often seen among works of Masamune and his school, and Shinto swords made in Soshu tradition.

kissaki
切先

The fan-shaped part of the blade above the yokote and the ko-shinogi. It may be whitened by polish. It's size is described as 'large' or 'small'.

ko-shinogi
小鎬

The part of the shinogi that runs from the yokote to the tip in the kissaki.

kurijiri
栗尻

Lit. 'Chestnut-shaped'. The rounded shape of nakagojiri.

It's the one of the most commonly seen shapes.

machi
区, 匸

The notches dividing the blade proper from the tang. The notch on the blade side is called hamachi; that on the mune side is known as the munemachi.

midare

Irregular. See midareba, choji midare.

mihaba
身幅

The width of a blade measured from the mune to the cutting edge. See also: moto-haba, saki-haba.

munemachi
棟区

The notch dividing the blade from the tang on the mune side. See machi.

nagasa
長さ

Blade length, measured from the tip to the munemachi.

nakago
中心

The tang of the sword; that part of the blade, below the machi, which is inserted into the hilt (tsuka). It is finished by hammering or filing, and often bears a carved signature. The hilt is attached by means of a peg (mekugi) inserted through a special hole (mekugi+ana) in the nakago.

Depending on the condition of nakago the following terms can be applied:

  • ubu (生ぶ) - for original, unshortened nakago
  • suriage (磨上) - for mildly shortened nakago
  • o-suriage (大磨上) - for greatly shortened nakago
nakagojiri
茎尻

The end of the nakago.

niku

Lit. 'meat'. ji having niku means that ji area is not flat, but rounded, curved in the cross-section.

Hira-niku - measure to describe the niku of hira area (also: ji-niku)
Ha-niku - niku of the area between the hamon and the cutting edge.

Niku can be described as full (平肉多い - hiraniku oi) or flat (平肉少ない - hiraniku sukunai).

o-suriage
大磨上

A "greatly shortened" nakago. The o-suriage nakago is formed from the part of the blade (originally), while suriage nakago is more just reshaped. In this case the signature is usually lost, unless orikaeshi-mei or gaku-mei have been performed.

orikaeshi-mei
折返銘

A way to preserve mei (signature) on the tang when shortening it (see o-suriage) by bending it around to the opposite side, therefore leaving it upside-down.

shaku

The shaku is an archaic Japanese unit of length which is commonly approximated to be 12 inches (1 foot). As with other measurements, it was originally derived from nature: the average length between nodes on bamboo. Since 1891, the shaku has been defined to equal 10/33 meter (approximately 30.3 cm, or 11.93 inches), or 3.3 shaku to the meter. A single shaku is divided into 10 sun (寸).

1 shaku = 11.93 inches (30.30 cm)

1 shaku = 10 sun
1 sun = 1.193 inches (3.03 cm)

1 sun = 10 bu
1 bu = 0.119 inches (0.303 cm)

1 bu = 10 rin
1 rin = 0.01193 inches (0.0303 cm)

sunnobi
寸延び

Longer than average wakizashi or tanto.

See jōsun for more details.

sunzumari
寸詰まり

Shorter than average (see jōsun) wakizashi or tanto.

tsukuri-komi
造込み

Overall construction of the blade.

ubu
生ぶ

Blades which weren't shortened (still have nakago in its original shape) can be referred to as 'ubu'.

yakiba
燒刃

The hardened area of the blade.