Samurai were the only people allowed to carry two swords, a pair called the daisho, (the “long and short”) as a badge of their unique warrior status. These two weapons, the long katana and the shorter wakizashi, were worn together although rarely used as a pair of weapons in combat. Miyamoto Musashi, the sword-saint and writer of the best-known book on swordsmanship, A Book of Five Rings, was unusual in that his “Two Heavens” fighting style did use two swords at the same time. One other sword is worth mentioning at this point, the no dachi. These enormous two-handed weapons were only ever used on foot.
The samurai used the katana to defend as well as attack and as a result never adopted shields, unlike the knights of Europe. They never needed to, because of the superb metalwork in the katana was good enough to act in both capacities
A samurai sword was carefully constructed out of many layers of steel and iron. The two would be hammered out and folded over many times to produce a “sandwich” of many layers. Each repeated forging doubled the number of layers of metal in a sword, in some cases 2²º — 4,194,304 — layers of metal would be the result. The maximum number of folds recorded is some 2³º (or 10,736,461,824!) layers of forged metal. This gave the sword enormous strength when the iron and steel were welded together. The iron at the sides and back edge gave flexibility to the blade, while the steel core could be hardened to make a perfect edge.
The final process in the forging was particularly clever. The blade was coated with clay built up to a different thickness across the blade: thin at the cutting edge and thick towards the back. When the sword — in its clay overcoat — was heated and then quenched, it cooled at different speeds and the metal crystals in each part in the blade ended up as different sizes. They were large where the clay had been thick, which meant that they were flexible, but small at the cutting edge, so they would form a hard edge that could be sharpened. Once the sword blade was polished, the change from the softer steel and the harder edge could show up as the yakiba, a line that resembles a breaking wave. Once the blade had been signed by the smith and hilt and guard fitted, the sword was ready for use.
The result of all of this was a sword that could cut a man in two — literally. Occasionally condemned criminals were used to test new swords, but it was more common to use a bundle of rushes and bamboo or to use corpses. Some swords had details of their testing carved into the tang (the piece of the sword inside the hilt).
Thanks to the resilience of such a blade, a samurai could block and turn blows that would have shattered any ordinary steel weapon. Its razor sharp edge gave him the ability to cut through an opponent right down to the bone. These two contrasting qualities were the result of the skills and experience that Japanese sword smiths had accumulated over centuries. No other sword, even the famous blades from Toledo in Spain, ever equalled these Japanese weapons. The katana is still probably the best hand-to-hand weapon ever produced.
Types of Swords
To – Sword, of the curved, single-edged type.
Ken – Sword, usually refers to the straight double-edged type.
Aikuchi – A dagger with no tsuba, typically worn by women.
Tanto – A knife-sized short sword, typically less than 1 shaku in length.
Shinai – Bamboo practice sword, used for Kendo.
Bokken – Hardwood replica of sword.
Bokuto – Hardwood replica of sword.
Suburito – Wooden sword, usually heavy.
Gun-to – War sword, usually refers to those made just prior to and during WWII.
Shinken – A real blade.
Koto – ” Old sword “. Blades before about 1600.
Shinto – New swords, from about 1600 to 1870.
Shin Shinto – Modern blades.
Iai-to – Practice sword for Iaido, usually not sharp.
Daisho – Great small, the set of two swords, daito and shoto.
Daito – Great sword, larger of the set of two, daisho along with shoto.
Shoto – The smaller of a pair of daisho, the other is the daito.
Tachi – Old style sword ( koto ) mounted edge down.
Kodachi – Equivalent to shoto, lit. ” small tachi ” with the same fittings as a tachi.
Uchi-gatana – Inside sword, forerunner of katana, worn in belt.
Katana – Same as daito. Mounted edge up.
Wakizashi – Equivalent to shoto, the shorter sword in a daisho pair, typically less than 2 shaku in length.
Measurement of the Sword :
Shaku = 30.2 cm. or 11.9 inches.
Sun = 1/10 of a shaku.
Bu = 1/10 of a sun, 0.3 cm
Nagasa – Measure of length of blade from kissaki to mune machi in a straight line
Sori – Measure of curve of blade from nagasa to mune at deepest point.
Sword Length Parameters :
Daito, Katana = 2 shaku.
Shoto, Wakizashi = 1-2 shaku.
Tanto = Less than 1 shaku.
Parts of the Katana
Omote – For tachi. That side that faces out from the hip when it is in the saya in its usual mounting. This side is signed by the swordmaker.
Ura – For tachi. Side that faces the hip.
Sashi-omote – ( Katana ) Side facing out.
Sashi-ura – ( Katana ) Side facing hip.
Tachi-mei – The side with the signature.
Katana-mei – The side with the signature.
Saya – The scabbard.
Kojiri – the ornament at the end of the scabbard.
Sageo – The cord used to secure the sword to the obi ( belt ).
Kurikata – The knob through which the sageo is passed.
Mekugi – The pin which holds the handle to the sword.
Saguri – the ornament which helps secure the scabbard when drawn.
Tsuka – The handle.
Kashira – The pommel at the end of the handle.
Tsuka-Ito – The braid for wrapping the handle.
Same – The ray skin which wraps handles under the tsuka-ito.
Tsuba – The handguard.
Fuchi – The cap at the end of the tsuka where it meets the tsuba.
Nakago – The tang of the blade.
Nakago-Jiri – The end of the nakago.
Mei – The swordsmith’s’ signature on the nakago.
Yasuri-mei – File marks on tang.
Hitoe – Back of tang, meets mune at mune machi. Also called nakago-mune.
Mekugi-Ana – The hole in the nakago for the mekugi.
Mune-Machi – The notch on the back of the blade to stop the habaki ( collar ).
Ha-Machi – The notch on the cutting edge of the blade to stop the habaki.
Tsuba-moto – 1/3 of blade nearest tsuba.
Chu o – Middle 1/3 of blade.
Mono-uchi – 1/3 of blade nearest tip, cutting area.
Katahaba – Measurement at the thickest part of blade.
Ha – The cutting edge of the sword.
Mune – The back of the sword. Mune types : Mitsu-mune ( 3 surfaces ), Maru-mune ( rounded ), Iori-mune ( standard 2 surface ).
Shinogi – Line of blade between shinogi ji and jigane.
Shinogi-Ji – The part of the blade between the shinogi and the mune.
Ji – The area between the shinogi-ji and the yakiba.
Hiraji – Area of blade between hamon and shinogi.
Jigane – Refers to the steel material. Jigane = skin steel. Shingane = core steel. These have different carbon contents.
Appearance of the jigane is controlled by the smith’s folding technique. Can be of different patterns, courseness, etc.
Hamon – The shape or style of the yakiba.
Hira – Face of the blade between shinogi and ha, includes hiraji and hamon.
Yakiba – The tempered edge of the blade.
Habuchi – Boundary of the yakiba.
Yokote – Line between edge plane and tip plane.
Mitsukado – Point where shinogi, yokote, and ko shinogi meet.
Ko-shinogi – Shinogi line through tip area.
Kissaki – The point of the sword.
Fukusa – Cutting edge in tip area.
Boshi – The shape of the temper in the point.