!!This is a work in progress. The contributor has made efforts to make sure that information is correct, but inevitably there will be errors that require future correction.

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[[folder:What makes the katana special?]]

A traditionally made Japanese sword blade (the katana is a Japanese sword, but not EveryJapaneseSwordIsAKatana) is defined by three things: being made of ''tamahagane'' steel, smelted from iron-rich sand in a large clay furnace called a ''tatara'' and folded several times to form a layered billet; being of laminated construction, of which the most common version--the ''kobuse''-style--is a high-carbon outer "skin steel" (''kawagane'') wrapped around and forge-welded to a low-carbon inner "core steel" (''shingane''); and being differentially hardened. Differential hardening is performed by applying insulating layers of clay to the blade, which are thicker on the back than on the edge. The coated blade is heated to a high enough temperature that it becomes non-magnetic, and then quenched in a trough of cold water. During quenching the edge cools rapidly and gets set into a very hard crystaline structure called martensite. The slower-cooling sides of the blade become not-quite-so-hard pearlite, while the core and back of the blade comprising the ''shingane'' ends up as malleable cementite, and may even consist partially of ferrite or pure iron. The pattern in which the clay is applied will determine the appearance of the ''hamon'', a cloudy pattern showing the boundary between the hardened edge and the softer body of the blade. Unlike a Western sword, the katana is not tempered after hardening. Differential hardening is also what gives the blade its curvature: unlike a curved sword blade made from a carbon-homogeneous piece of steel, which is forged in a curved shape before heat treatment, the Japanese sword blade is forged almost straight and actually ''bends itself'' into a curved shape as it's quenched because the edge and the body have different densities and thicknesses and cool at different rates. At first the blade bends forward because the edge is first to cool, but there is more and slightly-more-dense material in the spine, and as it catches up to the edge in terms of cooling it overpowers the initial tendency to bend forward and pulls the sword into its final backward-curving shape. If there was an error in the making of the blade it's possible that quenching will cause it to bend crookedly, in which case the smith has to start all over again.\\
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Japanese swords are made from bloomery steel. Iron-rich sand called ''setetsu'' is gathered and piled up together with charcoal inside the ''tatara'', and after smelting it comes out as a porous mass of iron and slag called a bloom, or in Japanese, the ''kera''. The kera is broken up into pieces, which are tested and sorted into three categories: ''hocho-tetsu'', which is low-carbon steel (about 0.2% carbon); ''tamahagane'', or high-carbon steel (1-1.5% carbon), and ''nabe-gane'', which is pig iron (>2% carbon). Swordsmiths choose the best pieces of ''hocho-tetsu'', ''tamahagane'', and ''nabe-gane'', while the lesser-quality parts go to blacksmiths and tool makers. The sword smith and his apprentices make a billet to form each part of the blade by flattening the pieces into plates, stacking them, and welding them together. The folding of a billet is performed by drawing it out, scoring it with a chisel, and then folding it onto itself so that the two halves are forge-welded together. The billet is repeatedly folded in order remove as many impurities as possible while spreading out any slag that remains, homogenize the distribution of carbon, and achieve the desired carbon level for each part of the blade. Before each heating and folding, the steel is coated in a mixture of clay, water, and straw ash to protect it from oxidation and carburization, with fayalite from the clay acting as a flux to assist in forge welding. Folding the glowing-hot billet removes impurities in two ways: it is like wringing out a sponge, causing substances other than iron to be squeezed out from between the crystaline structures of the iron by the blows of the hammer, and the heat causes non-oxidized impurities on the outside to bond with oxygen and get burned off. At the same time there are some substances, namely oxides, which cannot be burned off by the forging process and can only be spread throughout the blade so that a fatal flaw doesn't form somewhere. The tricky part of purifying the steel is that despite being desirable, carbon is also technically an impurity and it gets burned off as well. Each time the steel is heated and folded, it is decarburized a little more, so if your starting material has the carbon content you're aiming for, then you'll end up too low by the time you're done forging. Therefore, you need to pick starting material with ''more'' carbon than you're aiming for, so that after you've folded it as much as you intend, the amount of carbon will be just right. The ''shin-gane'' and ''kawa-gane'' need to have different carbon percentages, and therefore require different types of starting material. All three types of steel are used to make the sword. Thus the urban legend that the katana is made of brittle pig iron is only one-third right, and misleading to boot: ''nabe-gane'' is the starting material for the hardest part of the blade, but by the time it's been decarburized by folding it is no longer pig iron. It is possible to ruin the properties of a billet by folding too many times, and a billet should only be folded 8 to 16 times depending on which part of the blade it's for. Since the number of layers is doubled every time you fold it, over 16,000 layers are produced by folding only fourteen times.\\
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The traditional process is surprisingly effective at reducing slag and evenly distrubuting carbon when performed by a skilled smith and apprentices. At the same time, it cannot remove oxides that are not burned off by smelting at temperatures insufficient to melt iron, or by the forging process. The blast furnace was a technological improvement to the civilizations that adopted it because unlike a bloomery furnace, which can only melt the slag while leaving the iron intact as a spongy mass, it actually melted the iron and made it easier to seperate out the slag; the only problem then was decarburizing the resulting pig iron so that it could be used for tools and weapons. The ''kera'' smelting process is therefore obsolete and inefficient compared to more advanced methods adopted in other parts of the world such as Europe, and especially when compared to modern industry which produces better steel in greater volumes and with more consistency. The folding method is basically a clever but labor-intensive way to compensate for a deficiency in the smelting process, and once that deficiency is fixed then it becomes redundant. You cannot get any benefit out of folding a piece of modern manufactured high-carbon steel, because it's already as homogeneous and pure as it's ever going to be, and you're only going to start decarburizing it when you were already at the level you needed. That being said, there's an important difference between feudal era and modern Japanese sword making. Today the ''setetsu'' sand is harvested with the help of magnetic seperators, so purer sand is going into the ''kera'' in the first place. This means that Japanese swords made in modern times are of higher metallurgical quality than the old ones, even though the same primitive forging process is used. Tamahagane lacks an important benefit of modern steels, which is that with modern steel ordered from a factory you know ''exactly'' what you're working with and ''exactly'' how it's going to respond to forging and heat treatment. Huge companies have spent millions of dollars on scientific experiments to find out the exact chemical and mechanical properties of every alloy and carbon concentration of steel, which is very important because the optimal quench medium and cooling rate is different for each type of steel. Although a Japanese swordsmith can use traditional methods and his intuition to distinguish between pieces of tamahagane with different properties, he can only do so in a general way, and lacks the specific knowledge about his material that would allow him to tailor the heat treatment more precisely. Japanese tatara steel is one kind of steel, and the water quenching method was found to work well for it, but the reason that other makers of knives and swords use other media such as oil instead of water is that what works for Japanese blades is not necessarily best for other kinds of blades.\\
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Folded ''kera'' steel is still used in sword making today not because it's somehow "superior" to modern steel, but rather because it's valued as a historical tradition, and because it gives the sword the prized aesthetic effect of a grained surface pattern. The Japanese were far from the only culture to make swords out of bloomery steel, or to fold the billet to make patterned blades. Even the Europeans did it at one time! The Japanese just happen to be the most famous, and to have turned it into a very refined art. And for what it's worth, the result was adequate. Metallographic analysis of historical katana blades show that the fancy ones, at least, were quite structurally sound. Not all katana were well-made, of course, but neither were all swords produced by other cultures, either. And since it was back in the days before precise instruments like thermometers or modern knowledge of physics and chemistry, it was difficult to achieve consistency or for anyone to know exactly what they were doing. If you look at measurements from surviving sword blades of the European Middle Ages and Renaissance, the number of slag inclusions, the percentage of carbon in the steel, and the rate of successful heat treatment is all over the place, just as you'd expect. Comparing the metallurgy of Japanese blades with those of other cultures is frightfully complicated; the short of it is that the Japanese way isn't the only way to make good sword steel--and other, more modern methods may be a lot easier--but it's still a pretty impressive process, and it works.\\
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In contrast to the smelting and folding, which today are retained mainly for historical and aesthetic reasons, lamination and differential hardening ''do'' still have a functional purpose: they allow the sword to have a very hard edge--often with a Rockwell hardness of 60 HRC--which can hold its sharpness very well. If the sword were that hard all the way through, it would be very brittle and therefore likely to snap; in comparison, historical European swords are more often 45 to 50 HRC at the edge. It is often said that the tougher and more pliable back of the blade acts as a shock absorber to prevent the edge from taking damage, but this is actually incorrect; if the edge hits something that causes it to chip, there's nothing the back of the blade can do about it. What it does ensure is that a chipped edge will not spread into a fracture that compromises the entire structure of the blade, causing it to snap. Any trauma that can chip the edge will cause the rest of the blade to take a bend, rather than snapping off. Also, one explanation of the purpose behind the pattern of the ''hamon'' is that it helps to limit damage to the edge.[[note]]''The Art of the Japanese Sword'', by Leon and Hiroko Kapp, with Yoshindo Yoshihara[[/note]] Early Japanese swords had straight, narrow ''hamon'', but supposedly this sometimes resulted in the edge delaminating from the body upon impact. The solution devised during the Heian Period was to apply the clay to make a wavy or irregular ''hamon'', and to add thin clay lines called ''ashi'' across the edge which would leave unhardened lines separating the edge into compartments. The wavy ''hamon'' would act like a zipper keeping the edge mated to the back, and the tooth-like patterns would ensure that any chip was confined between two ''ashi'', sparing the rest of the edge.\\
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A "through-hardened" blade made from one homogeneous piece of steel cannot be made quite as hard-edged and will tend to dull more quickly, but has the advantage of durability. The hard yet brittle edge of a katana is more likely to chip if struck against something too hard and unyielding, such as the edge of another sword, which is why many parrying techniques in kenjutsu use the sides and back of the blade instead of the edge. Meanwhile, the blade consisting of a hard edge mated to a softer spine is more likely to take a permanent bend or twist if exposed to lateral force, taking a set from the kind of bending that a through-hardened blade would be expected to spring back from. A severe bend can interfere with technique and cutting performance until corrected, which would have been difficult in the heat of battle in the days when they were used as weapons, though at least this was better than a blade that had totally snapped. On the other hand, this same softness makes a bend easy to correct with the right method, whereas if a through-hardened blade ''is'' bent far enough for it to take a set, it will be harder to straighten out again than that of a katana. This is just one example of how the katana is not categorically superior to other swords, and whether or not it will serve you better than a different type of sword depends entirely on the context in which you're going to use it.
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[[folder:Origins of the Myth]]

Why do a lot of people seem to think the Japanese sword is superior? For the Japanese it's understandable that they'd want to brag about their swords being the best, but much more remarkable is the fact that people from all over the world seem to ''believe'' them. There are many possible explanations for this state of affairs, and the following are just a few suggestions.\\
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To begin with, Japanese culture both historically and today treats the sword as having special spiritual significance. From a Western standpoint, a sword is often seen as a weapon or a tool. Now what does this mean? Most Westerners who think about the katana, judge it more for it's functionality; how sharp it is, how well it can cut, and how nimble it can be used with two hands. From a Japanese viewpoint however, the katana is valued more than just it's role as a weapon. In Shintoism, the national religion of Japan, the sword is often portrayed as a divine sacred object. This is most evident in the founding myth of Japan, in which the two gods Izanami and Izanagi created the Japanese archipelago by dipping a sacred coral blade into the ocean before stirring it. So it goes to show that the katana in Japanese culture is valued more for it's divinity than as a weapon. Japanese swordsmiths, who also happen to be Shinto priests, are expected to religiously devote themselves in the forging the sword. They have to perform prayers and rituals before and after the forging to create an object that is sacred in value. Throughout the entirety of Japanese history, sword-making was recognized as a form of high art. Because the making, use, and preservation of traditional Japanese swords became part of Japanese identity, there was a very strong reason to preserve it instead of simply discarding it to make way for modernity.\\
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The Europeans did at one time in the middle ages elevate the cross-hilted knightly sword as a symbol of Christian chivalry, and later in the Renaissance treated the various side-swords and rapiers as symbols of manly honor, but fundamentally neither the Christian religion nor the nationalist myths of various countries gave the sword such singular importance that it could not be replaced with other symbols in accordance with the changing times. Furthermore, the swordsmith was rarely recognized as an artistic genius in the same way that painters and sculptors were from the Renaissance onwards, and the creep towards capitalism and industrialization tended to reduce the sword to the status of a commodity, either a piece of jewelry to be worn by aristocrats or a purely functional weapon to meet military needs. As the progressive technological improvement of firearms and artillery made the sword less relevant as a practical weapon, there just wasn't enough of a cultural movement to prevent the gradual die-out of European sword culture. By the 19th century the Europeans and the upstart United States didn't really ''need'' their swords to represent their artistic and cultural merit; they found more than enough reasons--whether military, technological, racial, or religious--to feel superior to the Japanese. To the extent that they grew to respect Japan more than other Asian countries, it was because the Japanese were the quickest to successfully imitate the European model of modernization. In that regard the sword contest was a low-stakes issue that they could afford to concede to the Japanese, because they thought they were so far ahead in everything else.\\
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Japan's sword culture has a special appeal for those who think OlderIsBetter, believing the craftsmen of olden times had secret knowledge that has been lost to modern craftsmen. Since Japan has a relatively continuous tradition of swordsmithing which goes back to the middle ages and lives on today, it can be said that they still make swords very similar to the old ones. Japan's status as an island nation and the "closed country" policy of the Edo period also meant that their sword-making tradition was less "diluted" by influence from their neighbors, thus encouraging gradual evolution rather than disruptive revolution and preserving its distinct national character. The various governments of Japan since feudal times have also helped to foster the craft of sword making and preserve its history, culminating in post-war Japan's laws regulating the manufacture, import, and export of swords while protecting the best antique swords as national treasures and important cultural properties. Admittedly, Japan has sometimes had periods of war and disruption which interrupted or destroyed certain sword traditions, such as during the Meiji Restoration when the samurai class was abolished and the wearing of swords outlawed, thus putting many of the old-fashioned swordsmiths out of work. Still, Japan's sword culture is more completely preserved than other Asian cultures that went through more prolonged cultural and technological upheaval, and is in a totally different league from Western Europe's Medieval and Renaissance traditions, which had to be resurrected after completely dying out. Although the first revivals of old European weapon-making and martial arts began in the 19th century, it was not until the rise of the internet in the 1990s and 2000s--accompanied by the publication of more translations of primary sources--that revived European sword arts really began to take off.\\
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Compared to Japan's traditional culture, which places more emphasis on tradition and basing present practices on the knowledge of one's ancestors, Western Europe has long been focused on the idea of progress and each generation being better than the last. The writers of the Renaissance and the Enlightenment created the idea of the [[TheDungAges primitive and superstitious Middle Ages]] because they thought they were so much better in comparison, and while they idolized the greatness of classical Greece and Rome, they nevertheless felt like they could build upon and surpass the achievements of the ancients. Despite the fact that there were always proponents of the GoodOldWays who resisted newfangled sword designs and fencing styles, each time they were ultimately drowned out by the embracers of change and improvement. While many swords associated with saints, nobles, and the like were preserved in churches or princely collections, they were not considered as templates for future generations of swordsmiths, and tended to be valued more for their history than for the intrinsic qualities of their blades. Contrast this with Japan, in which ''Kotō'' (古刀, "old swords") from around 900–1596 were considered the best and imitated by later swordsmiths, while the succeeding Shintō (新刀, "new swords") made from 1596–1780 were considered to be of lesser quality in comparison.\\
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Meanwhile in Europe the older types of sword fell out of use due to changes in warfare and fashion--replaced by newer styles until swords were eventually discarded altogether--causing the smithing and teaching traditions associated with those weapons to die out. The old swords went into collections and museums where hardly anyone handled them anymore, while many of the fencing manuals preserving these teachings sat forgotten in old libraries. This general unfamiliarity with the old tools allowed later European writers to conjure up the pervasive myth of medieval European swords as being dull, twenty-pound bars of iron that prevented any kind of sophisticated technique, either to distance themselves from the brutish violence of the Middle Ages or to depict proto-nationalist heroes like William Wallace or Richard the Lionhearted as possessing superhuman physical strength.\\
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The low opinion of European swords compared to Japanese ones has been encouraged by the fact that many Japanese blades have been fastidiously maintained throughout history--including modern museum-sanctioned repolishing which demonstrates some ValuesDissonance between Japanese and Western preservation mindsets[[note]]Western museums tend to regard removing the original patina as destructive to the object and the historical record, while custodians in Japan are more likely to think that historical treasures are best appreciated by continuing to use and maintain them[[/note]]--while many early European swords in museums today are in excavated condition, being corroded and sometimes partially disintegrated from lying in graves or the bottoms of rivers for centuries. It's like the difference between looking at a new car at the dealership and a rusted-out auto body at the junkyard, with the drivetrain gone and all the seats and interior stripped out. That wreck was a beautiful new car once upon a time, but it's hard to imagine its former glory just from looking at its dilapidated remains; an explorer from outer space who had never seen a new car before might conclude that automobiles must have been crude, inefficient, ugly machines, and much the same fallacy has been applied to old European swords.\\
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Fortunately there are still significant numbers of European swords which are in good condition, but most people will never get a chance to hold one of these swords, and they're unlikely to get a flattering impression from films, television, or even modern replicas. In films, stage fights, and shows at Renaissance Faires, {{Flynning}} and inaccurately-made weapons are the rule rather than the exception. Most budget-priced medieval European sword replicas on the market are inaccurate and cut corners: incorrect proportions, unergonomic hilts, too much weight, poor balance and handling, little or no distal taper, bad edge geometry and sharpening, cheap steel, and unreliable heat treatment make these weapons less impressive than historical ones were, and whoever handles one without understanding the difference will get the wrong idea. Uninformed consumers who aren't serious history nuts are unlikely to pay higher prices for good replicas that would give them a more correct and flattering impression.\\
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The first visit to Japan by the Portuguese in 1543 began the Occidental World's relations with Japan. Over time, European visitors would be impressed with the cutting ability of the Japanese sword, and brought back some hair-raising tales of beheadings, encounters with fierce pirates, and the like, even if those weren't always related to the weapons they wielded rather than to the swordsmen's ferocity and cultural approach to warfare (for instance, Spaniards from the Philippines talked very highly about their Japanese mercenaries' discipline and dedication, but rarely mentioned their weapons as something special). Naturally, some fine swords entered European collections either as diplomatic gifts or war booty. The isolationist policies of the Edo period limited the amount of direct contact beteen Japanese and Europeans, but by the mid-19th century Japan was forced to sign treaties that opened her up to the West again. This is when Europeans started forming many of the opinions about Japanese swords that they have today.\\
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The European sword industry was nothing to sneeze at, of course, and was especially distinguished by its access to good steel and ability to turn out large numbers of blades that were of at least decent quality. As early as the 16th century, Indian weapon makers were importing blades from manufacturing centers like Solingen, Germany so they could hilt them in the native fashion. The best Indian bladesmiths could make blades that were a match for anything in the world, and none of them were in danger of losing their jobs, but it was the "budget" market that got displaced by the European imports; for the same price as a crappy Indian blade, you could get a munitions quality blade from Europe that was a bit nicer and much more reliable. By the 19th century, especially after the adoption of the Bessemer process, Europe was awash in high quality, affordable steel. The downside to all this innovation was that the sword makers in the meantime had lost some of the traditional wisdom going back to the middle ages, and in some cases ended up having to reinvent the wheel.\\
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For example, scabbards made entirely out of steel had become common because of the need to mass-produce them, and also to make them durable since they would be taken on campaign by conscripts who didn't know the finer points of sword care and were likely to treat their swords and scabbards roughly. A wooden core was an additional expense, so they were often left out. Unfortunately, it turns out that wood is very good for preserving a sword's sharpness, while being kept in metal alone makes them dull really fast even if they've just been sharpened. British soldiers on colonial assignment were often frustrated that their swords would already have become dull within a couple weeks after sharpening, while their Indian and Japanese counterparts always seemed sharp and ready. At the time, the British were just as impressed with the Indian Talwar as they were with the katana, but for some reason that fact seems to have been forgotten by pop culture. European armies were also affected from time to time by a bad batch or some experimental new pattern that turned out to be a failure. Blades that weren't thick enough or that were tempered to be too flexible could fail to thrust through an opponent's greatcoat. There must have been quite a bit of envy, and a sense that the Indians and the Japanese knew something they didn't.\\
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The folding of the steel billet and the construction of the sword through lamination is always a major source of mystique for the Japanese sword. People tend to assume that the more handcrafting goes into something, the better the result will be. In many cases, such as the hand adjustments to make a hilt and scabbard fit a blade, this really does make a big difference. However, the invention of better smelting and steel-making technologies has reduced the amount of work that a swordsmith has to do in order to prepare the blank, and the raw material is often of better quality. We should consider, here, that what is most beautiful and what is functionally superior are not always the same thing. Many of the traditional processes are indispensible for creating the aesthetic qualities for which the katana is most loved, and fake effects such as a wire-brushed ''hamon'' are always easy to see through. It takes a certain amount of work to make something functional, but an amount of work far above and beyond that is needed to give it that kind of beauty and character.\\
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There may have also just been something deeply romantic about feudal Japan that orientalist Westerners admired. Europe and North America in the mid-to-late 19th century were in the throes of industrialisation, and society was changing so fast that it seemed scary and alienating. Therefore, when Europeans finally got a proper look inside Japan, they were surprised to find what to them seemed like a country in MedievalStasis. The people lived under a social order that resembled the structure of European feudalism, with lords living in castles and peasants working the land; the culture supported all kinds of traditional arts and crafts permeated with spirituality and appreciation for beauty; and there were samurai warriors who seemed to practice a code of conduct like that of medieval knights, whose MartyrdomCulture and embrace of HonorBeforeReason appealed to the romantic side of RomanticismVersusEnlightenment; and of course, the government had established the closest possible thing to FantasyGunControl by disarming the population, while enforcing HeroesPreferSwords by making the ''daisho'' the samurai badge of office. Despite the similarities with European history, everything there was so thrillingly foreign, oriental, and exotic, and there was enough ValuesDissonance between the two cultures to generate a lot of interesting drama. This combination of the familiar and unfamiliar contributed to the great fad of ''Japonisme'', the fetishization of all things Japanese. Of course, no sooner had the West gained unfettered access to Japan than the highly conservative social order was already in danger of collapsing from both internal and external pressures, to be replaced in the nationalist and modernizing Meiji Restoration. The samurai were a dying breed, and occidental observers sighed at their passing in much the same way that they lamented the passing of the NobleSavage who once roamed TheWildWest. The romanticized spirit of the samurai which the katana is said to embody is undoubtedly part of the reason it appeals to Westerners so much.\\
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Because of ForeignCultureFetish and lack of skepticism about stories from outside their own culture, people seem more willing to believe exaggerated stories of the katana than sword myths from Western cultures. While chivalric romances often featured knightly heroes chopping their plate-armored opponents in half from the crown of the helmet down to the saddle, not many modern people would mistake this as a thing that actually happened. In contrast, stories about Japanese soldiers cutting off machine gun barrels during UsefulNotes/WorldWarII still circulate the internet as urban legends. As Creator/GeorgeOrwell noted in "Notes on Nationalism", a person who's disillusioned with their own country can believe more ridiculous propaganda in praise of a foreign country than even the most jingoistic native of that country, because they haven't got the personal experience from living there which would make them know better.\\
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People who want to believe tall tales about the katana will move the burden of proof, claiming you can't prove that they ''didn't'' happen. If you take the stereotypical HypotheticalFightDebate where an army of plate armored European knights invades Japan in the 15th or 16th century--or vice-versa with katana-wielding samurai invading Western Europe--the fact that for obvious geographical and logistical reasons this ''didn't'' happen is rather convenient: whoever is already predisposed to believe that samurai would have chopped Western swords in half with their katanas and sliced through plate armor like butter is secure in the knowledge that there is not an event in the history books which proves this belief wrong. History buffs can count some chosen incidents where Spanish and Portuguese swords did clash against their Japanese counterparts, such as the battles of [[UsefulNotes/CagayanBattles Cagayán]], Manila and Fukuda Bay, but as those were, you know, literal battles, complete with artillery, fortified positions and all sorts of weapons aside from swords, it becomes a moot point again to rate their individual performances: the excuse tends to be that the Iberians prevailed in all those cases exclusively thanks to their superior firearms (after all, [[FirearmsAreCowardly no proper samurai would ever use such dishonorable weapons]], right?), leaving it open to claim that a knightly duel would have seen a wholly different result. And it should be fairly easy to prove through physics calculations that katana cutting through steel swords or gun barrels is impossible--which can also be determined from next-best-thing tests using the best practitioners and replicas available--but katana supremacists can potentially deny this conclusion as long as there still hasn't been a perfect experiment using a real antique masterwork katana wielded by an Nth ''dan'' master of the XYZ school of swordsmanship against a real medieval breastplate or WWII U.S. machine gun, which for reasons of cost and historical preservation is probably never going to be performed.

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[[folder:Pros and cons of the katana]]

The katana differs somewhat from the tachi, whose shape and method of wear indicate it was particularly designed to be worn and used while mounted and wearing armor. Katana were intended to be easier for a foot soldier to use, and could be worn very conveniently with civilian clothes as well as in armor. They are certainly well-suited for the quick-draw and attack that are required in self-defense situations, codified in the practice of ''iaido'' and ''battojutsu''. In the first place it is worn edge-up in its scabbard, thrust through the sash of one's clothes and fastened there with a cord. This way it is secure enough to wear about, but is also able to slide forward or back when the swordsman needs it to. With this method of wear one can quickly grasp the throat of the scabbard with the left hand and push it forward, so that the handle is delivered into the extended right hand; one draws the sword while simultaneously retracting the scabbard away from it, and makes the first cut almost in the same motion. The handle has an oval cross-section for comfort and help in aligning the edge, and is covered in rayskin and tightly wrapped in silk cord; the cord is absorbent and provides excellent grip--even if one's hands are covered with sweat or blood--and the rayskin protects the wood core from moisture while anchoring the cord wrap with its high-friction surface. The katana hilt also has only a disc-shaped guard (''tsuba'') without any knuckle bow or basket to hinder one from quickly grasping the handle. A brass fitting called the ''habaki'', wrapped around the base of the blade right where it meets the ''tsuba'', fits snugly inside the mouth of the scabbard when the sword is sheathed and is essentially the only thing that would keep the sword inside if you turned the scabbard upside down and shook it: as soon as you free the ''habaki'' by flicking up on the guard with your left thumb, or even just by squeezing the mouth of the scabbard, the rest of the blade slides right out with no resistance. That quick draw and ease of wearing it comes at a price, however. Compared to European swords with a cross guard, side rings, or basket hilt, the simple circular ''tsuba'' offers less hand protection.\\
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Another thing is that katana tend to be relatively short-bladed compared to other kinds of swords with two-handed grips. The length of a Japanese sword's blade--excluding the tang--is the ''nagasa'', a measurement based on an imaginary straight line drawn between the sword's point and the ''mune machi'', a notch at the back of the blade at the top of the tang. In other words, ''nagasa'' refers to the naked steel that isn't covered up by the handle. By modern defnition a katana is a blade of at least 60 cm (23 1⁄2 inches), while those exceeding 90 cm (35 7/16 in) are called ''odachi'' ("great sword") or ''nodachi'' ("field sword"). Matt Easton notes that antique katana that survive today normally have a ''nagasa'' of between 26 and 28 inches (66 and 71 cm). This may have to do with the average katana blade's relatively low amount of either profile or distal taper, which would make the blade heavier and more forward-balanced for a given increase in length. Also, admittedly, some of today's antiques were shortened during the 19th and 20th centuries when long blades were out of fashion. The broader average stated by Antony Cummins is 60-80 cm (23 1⁄2–31 1⁄2 in). In comparison, European longswords tend to be more like 35 to 40 inches (89–101 cm) in the blade, rapiers 40 inches or more, and even most one-handed sabers of the 19th century had more than 30 inches: keep in mind that an acutely tapered longsword or arming sword has a lot more profile taper than a katana, while a European saber would have more distal taper than a katana. Another category of Japanese swords, ''Nodachi'', could have blades of up to 130 cm; however, this trope is called ''Katanas'' Are Just Better, and by definition the katana is limited in length. A complicating factor [[https://youtu.be/J_S3tS4K_T4 pointed out]] by Cummins is that the height of people in that time and place may have influenced the length of swords. The average height of a Sengoku Period man as derived from period texts and skeletal remains was around 5 ft or 5 ft 2 in, which is shorter than a lot of present day people. A 6 ft tall person would need a 70 cm katana to keep the same proportional relationship as a 5 ft tall person using a 60 cm katana.\\
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On one hand, a short blade makes the typical katana handier in the close quarters of mass battle or indoor fighting, and it is easier to get out of the scabbard quickly than a longer-bladed sword such as a rapier. On the other hand, an opponent with a longer weapon can give the katana-wielder a hard time if he has enough room to take full advantage of his weapon's reach, particularly in thrusting play. That being said, the reach disadvantage is not as great if we compare cutting range. A rapier or an acutely tapered longsword has a narrow, bodkin-like point which is not well-shaped for cutting, and the center of percussion or "sweet spot" for cutting is quite a bit further behind the point due to the blade's cross section, profile, and mass distribution that is closer to the hand. The katana is relatively forward-balanced and has little profile taper, with a broad hatchet point suitiable for tip cuts, so the range of an effective cut could be greater than or equal to one made with a rapier, or one made with an acutely tapered arming sword or longsword.\\
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It is true that the katana is a fearsome cutter. The long, two-handed grip allows the sword to be wielded with power and control, and the blade is certainly designed for it. According to Matt Easton, the katana is relatively forgiving of a beginning cutter's technique. The blade is not so picky about hitting on its center of percussion because the profile taper, distal taper, and cross section change relatively little from the base right up to the tip, while the stiffness imparted to the blade by its thickness, minimal distal taper, and lack of spring tempering also make it less sensitive to the variables of cutting. The slight curvature also causes the tip of the blade to want to trail behind the other parts, making it somewhat self-correcting of the user’s edge alignment. In comparison, it actually takes more precision to cut cleanly through a tatami mat using something like a sharply tapered Western longsword, since you need to have perfect edge alignment and hit using a center of percussion relatively far from the point where the cross section and harmonics are just right. Mistakes are also more keenly felt using swords such as Western sabers, whose distal taper and springy temper make the cutting portion more wobbly and easily thrown off by poor technique. Other cutting basics are similar for both: As Keith Larman explains [[http://www.bugei.com/niku.html here]], cutting well requires that one both use a proper slicing motion and maintain a straight path throughout the cut, as introducing rolling or twisting motion at any point during the cut will create drag and put more stress on the edge. Because of the katana's unique hard-edged construction, however, edge durability is a particular concern. An acute edge of the type found on a ''hira zukuri'' style blade--one whose cross-section is a simple wedge shape with flat sides--can be made very sharp and is effective at slicing through soft targets such as human flesh and thick layers of cloth. Indeed, most ''tanto'' and some ''wakizashi'' had this kind of cross section. However, most katana from the age of the samurai were ''shinogi zukuri'', a style introduced sometime during the second half of the 10th century which features a ''shinogi'' or beveled ridge running down the length of the flat on each side. Many blades also had a generous amount of ''niku'' or "meat" to them, meaning that the surface between the ''shinogi'' and the edge bulged out somewhat instead of forming a flat plane. While the edge of this kind of blade would be less acute and therefore not quite as razor-sharp, there was more material to support it in case of an off-angle cut or impact against something hard, like armor or another blade. A blade with a lot of ''niku'' will also produce less drag than a flat-sided blade while cutting through thicker and heavier targets, since it has a way of parting the material as it passes through while minimizing the amount of the blade's surface area in direct contact with the material. One might say that blades had to be somewhat overbuilt back in the day, since the quality of the steel and of the heat treatment was often unreliable. An acute-edged ''hira zukuri'' katana might have been in danger of snapping in the old days, but the durability risk of making a katana-length ''hira zukuri'' blade is far less significant if the smith takes advantage of modern materials and methods.\\
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In any case, one should not get the impression that the katana's impressive cutting performance is unequaled, since many swords designed for cutting such as Oakeshott type XIII medieval knightly swords, Persian ''shamshir'', and Chinese ''dao'' can achieve similar results in cutting tests. The fact that these blades are very diverse in shape and construction indicates that when it comes to designing a sword for performance, "there's more than one way to skin a cat". Also, in terms of stunts such as cutting thin sheets of metal or slicing bullets in half, closer inspection will often reveal it to be a DeceptivelySimpleDemonstration that any kind of well-made sword could do in the right hands and under the right conditions. It goes without saying that a katana cannot slice the barrel off of a machine gun or slice another sword blade cleanly in half, since sharpness is simply beside the point in that situation and no sword would be able to do it. While there are some exceptions, a good rule of the thumb is that if another sword can do it, the katana can probably do it, and if another sword can't, then the katana probably can't.\\
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A curious fact about the ''katana'' is that, contrary to popular belief, the curvature is not a major factor in how well it cuts. Compared to dramatically curved swords like certain Indian talwars and Persian Shamshirs, the typical katana blade actually has a very shallow and subtle curvature. Unlike the latter swords, where the curvature is added during forging, the curvature of the katana is usually a mere side effect (albeit an aesthetically pleasing one) of the differential hardening process. In the 19th century, the British sword manufacturer Wilkinson reported that slightly curved sabers were not found to cut any better than straight sabers with similar cross section and edge geometry, and that the only reason to still include a slight curve was to make it easier for the wielder to align the edge properly in the cut. Only steeply-curved models like the Tulwar-inspired Pattern 1796 Light Cavalry Sword showed the expected benefit. This can be explained by the fact that a draw cut like the ones seen in Indo-Persian swordsmanship pulls downward on the hilt of the sword as the cut is made so that the blade will enter the target at a lower point on the edge and exit at a higher point on the edge. The distance between these two points of contact shows the effective length of edge that is dragged through the cut, and a greater length of applied edge will produce more slicing power. Simulating this situation shows that the difference in cutting ratio between a typical slightly curved katana blade and a version that is straight is insignificant. The katana's cutting ability is sufficiently explained by its sharpness-retaining edge, stiffness, cross section, hatchet point, two-handed grip, relatively forwards balance, and the ease of edge alignment.\\
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A note about thrusting. The katana can thrust surprisingly well, despite having a "hatchet point" and despite being curved. In fact, the inherent stiffness of the katana (caused by the thick cross section, lack of distal taper, and lack of spring tempering) is an advantage when trying to thrust through anything. Attacks with the point (''kissaki'') are a significant aspect of ''kenjutsu'', and tests suggest that the sharp-edged point of the katana would have easily penetrated the human body, even through thick layers of cloth armor or clothing. The ''kissaki'' was perfectly adequate for seeking the weak spots in Japanese armor, which had relatively large gaps between the major lammelar pieces and used a kind of butted mail that would have done more to stop a sword cut than a spear point. The katana point might not have been ideal for slipping through the gaps in European-style full plate armor or penetrating four-in-one pattern riveted mail the way a stiff and narrow knightly longsword or estoc would be, but since they did not encounter those defenses, it wasn't a problem. Presumably if they had faced such difficulties, they would have had to consider making changes. The hatchet point of the katana facilitates the use of tip cuts, so it had its advantages. In any case, the thrust remained secondary to the cut in Japanese sword technique, and while there were various point styles there was no pressure to dramatically change the shape of the katana to make it better at thrusting. The blunt spine of the katana is convenient for half-swording, which is done in many ''kenjutsu'' techniques in order to attack at close range with either the edge or the point. It is also technically possible to half-sword in the European manner by wrapping your hand around the blade--and do so without hurting yourself on the edge--but Japanese half-swording simply uses the hand to support the spine.\\
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The modular construction of the hilt is useful and convenient, but also relatively delicate compared to the European method of wedging the crossguard onto the shoulders of the blade and securing the pommel by peening the tang over it. The tang of a Japanese sword is secured inside the handle mainly by a very snug fit with the grip wood and a single wooden peg that passes through a hole in the tang, though copper pegs and/or a second peg are sometimes found on modern reproductions. This makes it possible for a Japanese sword's owner to disassemble and change the fittings with hardly any tools, unlike a European sword which has to be taken to a cutler for re-hilting. However, this reliance on the smooth fitting of handmade parts makes it more potentially sensitive to damage. The pommel is just a cap on the end rather than a hefty metal knob, and the tang does not pass all the way through the grip. And, as mentioned already, the katana is relatively forward-balanced and doesn't have as much mass concentrated in the hilt. Thus while the katana can make effective pommel strikes like other swords, the European technique called the "murder stroke"--where the blade is grasped with both hands in order to swing the hilt like a hammer--would not be very advisable or effective with a katana.\\
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One simple reason that katanas might not be "better" in a modern situation is their price. As already mentioned, making a katana in the traditional way is extremely labor-intensive. This is why, [[http://www.sword-buyers-guide.com/high-quality-katana.html according to Sword Buyers Guide]], the starting price for a newly made katana from a licensed Japanese swordsmith is about 4,000 USD, with the average being closer to 7,000 USD; the best quality can cost up to 30,000 USD, and you can hardly ever order them online; you would probably have to go to Japan and prove to the swordsmith that you’re worthy of owning the sword! If you can't afford a bespoke sword made in Japan, there are cheaper alternatives from China. High-quality Chinese-made katana with folded blades come in the $1,000-2,000 range; you would not want to buy a folded katana for less than this, because the steel quality or forge welds are more likely to be defective, which would actually make it ''worse'' than a cheaper one made from mono steel. A decent, functional Chinese-made katana with a through-hardened mono steel blade can be bought for as little as $300, though you'll normally have to go above $600 to get high quality. The main sacrifice of mass-produced katana comes in fit and finish, especially regarding the ''tsuka'' (hilt) and fittings. And by Japanese law, a sword isn't a ''nihonto'' unless it is made from ''tatara'' steel using the traditional methods, so your mono steel Chinese-made sword technically isn't a "real" katana despite what the marketing may tell you. Also, there's maintenance. Regardless of whether it's a priceless antique or a relatively modest modern sword, if yours is traditionally made then you can't just polish it the way you would one of mono steel, but have to use more skill- and labor-intensive methods. Perhaps it isn't necessary from a purely functional standpoint, but you have to take it to a professional polisher if you want it to look its absolute best, which can cost upwards of $100 per inch. All that comparison is moot if you live in Japan, however, because the manufacture or import of non-native swords is forbidden by Japan's gun and sword law. There, as a result, the traditionally made Japanese sword is the ''only'' real (i.e. made of steel and sharpened) sword you're allowed to own, making it "just better" by default.\\
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The performance differences between through-hardened and differentially hardened katana blades made in a similar shape are relatively minor: one thing that may be seen as a benefit is that a differentially hardened katana feels more "harmonically dead" compared to a through-hardened one, meaning that the vibrations from hitting somewhere other than the blade's center of percussion are less pronounced, making it more forgiving of the user's technique. It can also have a slightly harder edge than a through-hardened katana. That doesn't mean that the maximum sharpness will be increased; if they're both freshly sharpened, then you won't get any measurable difference when cutting tatami mats. However, it does mean that the edge can remain that sharp for longer compared to a through-hardened blade throughout a day of cutting or after a long period of storage. As for durability, a through-hardened katana can spring back from abuse, whereas one should be wary of destructive testing on a traditionally made katana, lest it take a set or a twist that would be difficult to straighten out.\\
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In a fictional setting, the katana presents some more issues. As a cutting sword, it evolved in an environment where armour was typically extremely light and relatively ineffective compared to some of its contemporaries, as can be seen on the Viking v Samurai episode of Deadliest Warrior - even though the katana can cut through mats representing Japanese armour with ease, it's stopped dead by the chainmail worn by the Vikings. Due to the sword's design, it is somewhat more fragile than western counterparts, particularly with the hilt, which means that, unlike bigger, stronger swords like the Zweihander, it can't be used as a substitute club against armour which protects from slashing - chainmail, plate, even tougher leather armours could be expected to stop the sword dead, which is especially problematic against opponents like knights or well-equipped vikings, who wore armour which would have protected them quite handily from strikes from a slashing weapon like the katana. In a modern setting, this is also true of stab vests, which can be purchased much more cheaply than a katana can, as well as, theoretically (though as far as I can tell, never tested), ballistic vests, which might be able to distribute a blow from the katana enough to prevent it cutting. It is, however, definitely true of modern ballistic armour and riot gear, as well as vehicles. The katana was never designed or built to be capable of cutting through metal, and no katana would be able to cut through things like car doors, guns, other swords, metal shields, and especially not tanks (don't believe everything you see in anime, folks). A katana might be a fearsome weapon in the hands of a trained opponent - the same is true of any weapon. As a cutter, the katana is most effective against unarmoured opponents, as it, like any good cutting sword, is capable of striking multiple organs or arteries with one blow. If a character is tending to remove limbs with ease, they probably want a chopping sword (the half-way point between axes and swords, check out the variations on the machete, like the Bolo used in UsefulNotes/{{Eskrima}}, or things like the kukri or kopesh). If the character is fighting armoured opponents, they're most likely to have a piercing sword, like an estoc. If they don't know what kind of opponent they might face, a cruciform sword is generally the JackOfAllStats of swords. Generally speaking, the katana is a sword that has its reputation vastly overblown in some media, and undersold in others. It's a situational weapon, and, typically, many writers do not consider the situation in which it is used as a factor in its effectiveness.
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[[folder:What About Zombies?]]
As a bonus round, what are the pros and cons of a katana in a ZombieApocalypse context? From Literature/WorldWarZ to Series/TheWalkingDead2010, katanas are a go-to choice. And in fact, it's hardly the worst choice you could make. Against zombies, first of all, cutting or chopping is bound to be more reliable than thrusting. A thrust does nothing to slow down a zombie unless you nail it right in the brain; the thrust can usually only threaten one zombie at a time; and there is a risk of the blade getting stuck in the zombie's body when you try to withdraw it. A cut can damage or dismember a zombie even if the brain is not destroyed; a cut can damage or hold multiple zombies at bay; and the blade is less likely to get stuck. As we already established, the katana is a good cutter and one which is fairly forgiving of technique, which would come in handy for a survivor who happened not to be a master swordsman, or one likely to be fighting in situations of panic or confusion. Furthermore, the katana is something of a hand-and-a-half-sword. One can either go two-handed for power, or wield SwordAndGun together. All that said, it would be better for the sake of durability to take a modern-style replica katana with a mono steel blade and reinforced hilt. The zombies aren't going to give you any points for artistic and historical accuracy. You could also substitute other kinds of swords and get very similar benefits, such as a 19th century cavalry sabre or a Chinese dao.\\
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There are some problems with the katana as a zombie weapon, and they have less to do with the katana in particular than with swords in general. A sword with a roughly 30 inch blade can be a bit bothersome to wear, and becomes awkward to use in confined indoor spaces. Various sword designs from earlier in history might also lack the appropriate design philosophy, being designed in general for warriors who expected to occasionally fight similarly-armed opponents in short, sharp combats requiring a light, well-optimized weapon. It was not expected to pull double-duty as a tool, since there tended to be a separate logistics train to take care of the warrior's needs, and as long as it survived any particular combat it was easy to send the sword to a sharpener or cutler for repairs afterward, or in the worst case to simply buy a replacement. Contrast that with the survivor of the zombie apocalypse, who is living hand-to-mouth with few if any human allies to trade or cooperate with, needs to potentially carry any useful tools on their person, and may have to chop through dozens or hundreds of zombies before being able to find a suitiable replacement blade. In a survival situation where weight and resources are at a premium, having a lightweight, tough little number that requires little maintenance and fulfils multiple functions [[BoringButPractical will serve you much better than any fancy sword]]. Contrast the [[MacheteMayhem machete]] or carpenter's hatchet (edge on one side, hammer on the other), which would be three times tougher than the sword while also being a third of the weight, and being half the length limits the reach but allows you to swing it in a tight corridor or doorway. The humble crowbar is even more of a foil to the sword; as it's just a lump of hard iron that needs hardly any maintenance and also can be used to pry open (or bar) doors, break containers, and lift heavy objects.
[[/folder]]