aikuchi

Used to describe all sword mountings which do not have a guard, tsuba, between the handle, tsuka, and the scabbard, saya. Often it is used as an abbreviated form of the term aikuchi tanto, in reference to a type of guardless dagger, frequently mounted in a highly decorated fashion, that first developed in the Kamakura Period (1185-1332).

arato

The first stone in the series of natural water stones, used to shape and polish the blade.

ashi

Literally mean "legs", lines of martensitic structure projecting into the ha perpendicular to the hamon.

ayasugi-hada

A grain structure in the steel of the ji that has regular wavy texture, resembling the grain of the wood from the sugi (cryptomeria) tree.

bar stock

Modern homogeneous steel.

bo-hi

A single large groove running down the length of the blade. Also pronounced bo-bi.

bonji

Decorative carvings on the side of the blade of stylized Sanskrit characters.

boshi

The section of hamon that is in the point of the blade.

chisa

"small" Used as a prefix to many Japanese sword terms: chisa-katana "small katana".

chu

"medium" Often used in Japanese sword terminology: chu-kissaki "medium point", chu-suguha "medium width suguha hamon".

daisho

A pair of long and short swords (usually a katana and wakizashi), worn edge upwards and thrust through the belt, that came into widespread use during the Momoyama Period (1573-99). Often mounted with matching and/or complimentary koshirae. Literally, "big-little".

denkaitetsu

Electrolytic sponge-iron, a super pure form of iron, a by product of electric hearth furnace. Some Japanese swordsmiths, using the process of oroshigane, alloy carbon with this iron to form a bloom of steel with nearly the same chemical composition and appearance of tamahagane.

fukura

The cutting edge of the kissaki, the point, running from the yokote to the tip of the kissaki.

fumbari

A term used to describe taper in the width of the blade from the machi to the kissaki, the point.

ha

The cutting edge of the sword.

habakimoto

The area of the blade covered by the habaki.

habuchi

The line which forms the boundary between the hardened cutting edge, the hamon, and the soft body of the sword, the ji.

hamachi

A notch on the cutting edge of the blade, opposite the munemachi, which defines the beginning of the nakago.

hamidashi

A tsuba for a tanto, which is only slightly wider than the fuchi.

hamon

The visible outline that differentiates between the unhardened soft back and the hardened steel cutting edge. The hamon marks the change in structure in the steel, the soft pearlite and the hard martensite. Often the hamon is mistakenly called a "temper line". However, Japanese swords are not tempered, they are differentially heat-treated in a process known as yaki-ire.

hi

Grooves carved into the sides of a blade.

hira-zukuri

A blade type, tsukurikomi, flat with no ridge.

hitatsura

Literally means "burnt all over". In addition to a normal hamon, the blade also contains hardened regions throughout the sides of the blade.

ho wood

Wood from the Japanese Bigleaf Maple, Magnolia obovata. Traditionally used for saya. Because it is strong, light, and easy to work, the wood highly sought after by craftsmen.

itame-hada

A surface texture of the ji, described as resembling wood cut against the grain.

ito

Literally means "string", but is used in reference to the strong flat woven silk cord usually used to wrap the handle of a sword.

ji

The area between the ha and the shinogi.

jizo

When discussing Japanese swords, it refers to a boshi with a rounded "head-like" shape, which resembles the profile of stone figurines of the popular Buddhist bodhisattva Jizo.

katana

A Japanese sword developed to be worn cutting edge up by infantry to allow drawing and striking in a single stroke.

kissaki

The point of the blade, usually defined by the yokote line

ko-maru

A boshi that follows the point and then forms a small circle as it turns back before it reaches the mune. Literally means "small circle".

maru-mune

The back of a blade, mune, which is rounded.

mei

The signature of a sword's creator, located on the nakago. The signature is chiseled on the side of the nakago which faces away from the body when the sword is worn, i.e., for blades which are worn edge up, like katana, the mei is located on the side of the word which has the edge to the left. In the case of tachi, which are worn edge down, the signature is on the opposite side.

meito

“A sword with a name”. A masterpiece officially recognized as such.

mitsukado

The point where the yokote intersects the shinogiji. Literally means "three corners".

moroha-zukuri

A blade shape which has two cutting edges with hamon on both. Moroha-zukuri was developed solely for tanto.

motohaba

The width of the mune at the machi, where the polish blade ends and the tang begins.

mu-zori

No curvature, a straight blade.

mune

The back of the blade.

nagasa

The length of the blade, as measured from the tip of the kissaki to the mune-machi. Traditionally, the length of Japanese blades is measure in shaku.

nakago

The tang of the blade, which slides inside the the tsuka.

nakagojiri

The butt of the nakago, also refers to the shape of the bottom of the tang.

nanako

A surface treatment, often used on shakudo, with the appearance of fish roe, consisting of tiny individually punched hemispherical granulations.

o-kissaki

A large point.

oroshigane

The process of adjusting the carbon content of tamahagane in order to make steel suitable for swords. Today, the term is also often used to distinguish handmade steel in the Japanese tradition.

osujikai yasurime

A type of yasurime with file-marks that slope steeply towards the back of the nakago.

pattern-welding

The process of forge-welding different steels and folding or otherwise manipulating the billet to produce a distinct pattern of contrasting steel composition.

sakihaba

The width of the mune at the yokote, where the kissaki, point, begins.

same-kawa

The skin of a stingray. Also called same. The handles, tsuka, of most koshirae are wrapped in same.

saya

The scabbard of a Japanese sword.

sayashi

A scabbard maker.

sensei

Japanese for "teacher".

seppa

Copper washers that slip on the tang on both sides of the tsuba between the saya and the tsuka. If a sword's tsuka becomes loose, it can often be remedied by replacing the seppa with slightly thicker ones.

shakudo

An alloy of copper and gold.

shibuichi

An alloy of copper and silver, often used for fittings of Japanese swords.

shinogiji

The area of a blade between the shinogi and the mune.

shobu-zukuri

"iris leave style" A blade geometry of nihonto where the shinogiji runs nearly to the point and the point has a long drawn out curve. Shobu-zukuri blades do not have a yokote line.

single-twist

Steel cable which as been twisted tight during forge-welding and then drawn out into a sunobe.

sori

The curvature of a blade.

suguha

A straight hamon.

tachi

A long curved sword worn cutting edge down on a belt and intended for use from horseback.

tanto

A short Japanese sword or dagger, considered to be limited to under one shaku.

tori-zori

A sword whose curvature is strongest towards the center of the blade, between the kissaki and the machi.

tsuba

The guard on a Japanese sword, which slides onto the nakago between the habaki and the tsuka. Tsuba can vary from a simple plate to elaborate pierced and carved masterpieces.

tsuba

The guard. Koshirae are mounted with tsuba, while shira-zaya are not. We here at Dragonfly Forge generally make our own tsuba, ranging from simple plate to elaborate folded antique wrought iron with piercings and carvings.

tsuka

The handle of the sword, which is constructed with a carved wooden core, which slides onto the tang. The core is wrapped with same, which often itself is wrapped in ito.

tsukiage

A boshi which forms a sharp point as it turns back.

tsukurikomi

The basic structural shape of the sword. Common tsukurikomi are shinogi-zukuri and hira-zukuri.

tsunagi

A wooden replica blade, used to mount a koshirae while the original blade rests in a shira-zaya.

uchi-zori

A blade with “reverse curvature”, which curves forward towards the point.

wakizashi

Japanese swords of medium length, generally between one and two shaku (approximately between one and two feet).

wari-bashi

A pair of chopsticks, hashi, which are mounted in the saya and appear like a kogai that has been split down the middle. Also known as wari-kogai.

wari-kogai

A kogai which has been split down the middle, to be used as chopsticks. Also known as wari-bashi.

yaki-ire

The process of heat treating the blade in order to produce a hardened edge and a soft, unhardened, back.

yasurime

Filemarks on the nakago, which serve as the background for the mei, signature, if any exist. Yasurime vary from smith to smith and from school to school, and can provide additional information when investigating a sword's origins.