Command for the sword of god version 1.11. How to make a sword out of paper: do it yourself and at home

Historic home decor is easy to make yourself. It is in today's publication that we will talk about how to make a sword from wood and other materials. The Homius edition will help you to get acquainted in detail with some of the design features of this weapon.

PHOTO: dbkcustomswords.com

Bright, elegant and beautiful weapons can be performed by everyone. However, it is important in advance to determine exactly which of the materials to choose for the basis of the structure. In fact, with the skills of turning and carpentry, you can create a serious weapon for training and collection from metal and wood. Moreover, such copies are being sold very successfully. Many collectors are willing to buy up Hand-Made options.

PHOTO: bloknot-stavropol.ru

Suitable sizes of edged weapons

If you believe the standards that came to us from antiquity, then the length of the sword should be approximately equal to half the height of a warrior. To more accurately determine this, it is necessary to measure the height from the foot to the palm in a position lowered at the seams. If you hold the sword in your hand, bent at the elbow, then its tip should be in contact with the chin.

PHOTO: comp-pro.ru

Be sure to take into account not only the length, but also the width of the future blade. The weight of the finished product is also taken into account.

1. The weight of the structure should be no more than 3 kg, otherwise it will be very difficult to control this weapon.
2. If the sword is short, then the length of the blade should be 60-70 cm, as for long models - 70-90 cm.
3. The width of the handle is 2.5 times the width of the palm, while it should have a comfortable design. The size of the palm is taken precisely by the future owner of the weapon.

In fact, you can take into account a lot of other parameters, but these data are quite enough for the production of models from natural wood and metal. For example, wooden swords for children should be lightweight.

PHOTO: liveinternet.ru

How balancing is done

Balancing is the same center of gravity that is taken into account in the production of different versions of melee weapons. Mostly it is located in the area of ​​the beginning of the cutting edge of the blade.

If the center of gravity is shifted lower, for example, to the middle of the blade, then the impact force will be small. When the balance is closer to the handle, it becomes much more difficult to control the melee weapon.

PHOTO: pikabu.ru

To center the sword correctly, you need to hold it on one index finger and move it to the left and then to the right until the structure is balanced.

How to make a sword out of wood with your own hands

Wooden edged weapons do not take long to grind, the main thing is to pre-prepare all the inventory for the work process. Such options are most often made by grandfathers to their grandchildren for games and training. And if you make a carved sword from a board, then it will come off as one of the objects of the historical collection.

PHOTO: whitelynx.ru

What materials and tools you need to keep close at hand

As a rule, special tools are not required to make a sword from wood. Usually every man has all this on the farm. In order to carve a sword out of wood you will need:

• saw on wood or;
• a sharp knife, a simple pencil (preferably a painting one, it is stronger);
• sandpaper;
• tape measure, ruler and measuring tape
• chisel;
• drawing of a sword for cutting out of wood.

PHOTO: rock-cafe.info

Crafting a weapon kit

Firstly, in order to make a wooden sword with your own hands, it is imperative to create a template and make blanks using it as an example. This is done as follows.

Illustration	Description of action
	We sand the board well, and then carry out the transfer of the sketch from the template to its front side. We draw clear lines
	Using a jigsaw, we cut out the workpiece along with the handle and the blade itself
	With the help of a chisel, we make the corners on the handle more rounded and symmetrical on both sides.
	We carry out grinding of all corners and cut ends. We remove all the jags completely until the material is completely smooth.

The part is ready for the next stage of processing and applying the finishing touches. Using thinner wood, you can create a sword from wood for children with your own hands.

The final stage: assembling the sword

Initially, we will make all the corners more rounded and safer, after which we will proceed to the next stage of creating the weapon.

Illustration	Description of action
	With a chisel we make a pattern on the handle, thereby separating it from the blade
	Additionally, we grind the product, measure the handle, whether it fits the hand. If not, we perform a slight trimming with a chisel to optimal parameters. Getting the perfect DIY wooden sword holder

If necessary, you can paint the structure, or in place of the handle on the sides, attach metal plates of the same type using.

On a note! If you remember childhood, then most children and girls made swords from ordinary sticks.

How to make a katana sword with your own hands from metal

Training edged weapons should only be used for their intended purpose. Safety must be observed during fencing, as this structure is dangerous. Only adults work with her.

In order to forge a sword you need:

• a sheet of metal (even an old one is suitable) with a thickness of 3-5 mm;
• and a sander;
• vice;
• other tools for metal processing.

You can make an iron sword for fencing with your own hands using a simple algorithm.

Illustration	Description of action
	We draw a sketch of the future product on a piece of metal, then cut it out with a grinder along the contour. If there are welding seams on the material, they are grinded. Two identical parts and one flat part are created. These three elements are welded together so that the same parts form a small angle
	As a result, you should get this shape of the blade. It is additionally hammered with a hammer to slightly flatten it. The welded handle is ground together with the blade
	Then a steel plate is put on the border of the handle, bent with a vice
	Create a template for the limiter and put it on the handle with pre-shaped washers
	We create a handle from a wooden block, frame it with metal plates and glue it on top with leatherette

It remains only to glue the handle to the sword, making it a braid of red leatherette. So it is possible to make an almost real sword.

We make a simple sword with our own hands at home: simple ideas that will delight a child

Which of the boys has not dreamed of becoming a real warrior? Believe me, creating a toy sword will bring your kid a lot of joy and pleasure from the process. Moreover, the toy will be as safe as possible.

PHOTO: tytrukodelie.ru

DIY plywood sword

Plywood can always be obtained at any hardware store. It is quite easy to work with this material as it has a fine but strong enough texture.

1. We prepare a template or drawing, on the basis of which we will make a sword with our own hands.
2. We redraw it on a sheet of plywood, and then cut it out with a hand or electric jigsaw.
3. Using sandpaper, we grind all the edges well, paint the workpiece.
4. Next, we treat it with varnish or waterproofing agent.
5. We leave the weapon to dry for a few days.

PHOTO: in.pinterest.com

Such a product looks great not only as a toy, but also as a decorative element. To make a sword at home that looks more impressive, you can make a carved blade, for example, with interesting teeth on the inside.

PHOTO: in.pinterest.com

PHOTO: dxfprojects.com

How to make a cardboard sword with your own hands

A cardboard product is made according to the same principle as plywood. For the design, you only need packing boxes from any household appliances. Next, we make edged weapons according to the algorithm.

Greetings, brain brothers! Here is a detailed guide on how to create the magnificent Barbarian sword. Not a decorative thing, but a high-quality and beautiful sword!

Since I decided to create myself a Barbarian sword, I am a hunter by nature, and a lot of time has passed until the moment of its incarnation. I think this happened not because of a lack of desire, but because it took a lot of time to acquire materials, the necessary equipment, and, of course, knowledge - I think this is true for many projects.

There are over 200 photos in this guide, so I won't go into my steps in detail, let the photos speak for themselves.

Design criteria: I wanted to make a beautiful sword, a little in the "fantasy" style, but without losing its properties, that is, it must be durable, functional, made of decent steel and with high-quality elements. At the same time, the tools and materials used to make the sword should be available to many, and not expensive.

Roughing the blade: Since I have neither a forge nor an anvil, I decided that I would carve rather than forge my sword from a strip of metal. As a basis, I took 1095 high-carbon steel, which is an inexpensive steel recommended for knife makers. In general, if you are planning to make a good blade, it is better to use hardened stainless steel, and if a "wall hanger", then you can use less expensive steel grades. And more, if you live in humid climate, then take into account the composition of steel in terms of carbon, since high-carbon steels rust very quickly.

Step 1: gutter

A groove is a groove that runs along the length of the blade, you probably heard its other name - bloodstream, this is not true, since its main purpose is to reduce the weight of the blade. In this case, it is a purely decorative element. To find out how it is made, I spent a lot more time than making it.

The depth of the groove is chosen relative to the thickness of the blade, and you should not deepen the groove too much, as this will weaken the craft. I made a groove on each side with a depth of 0.16cm, while my sword is 0.5cm thick.

Step 2: mounting base

Now we will make a mounting base for the sword and will use it throughout the entire process of creating the sword. It allows you to better handle a knife, grind, shape, etc. The blade is flexible and soft, so I don’t regret taking the time to create the mounting base, because with it I made a sword of excellent quality.

I made the base itself from scraps of lumber, just gave the board a little sword shape and installed the fasteners.

Step 3: blade

I sharpened the blade using the old-school technologies - by hand, with a file, without whetstones, grinders and other devices. I spent at least 4 hours on the whole thing, and I think if you do it all the time, you can save on gym... So, brain file in your hands!

And some tips:
- if you are planning the subsequent hardening of the blade, then do not sharpen the blade to sharpness, leave a cutting edge with a small thickness of 0.07-0.15 cm. This will prevent cracks and deformations during the heat treatment process.

- constantly check the correct geometry of the blade. To do this, it is convenient to shade the initial canvas with a marker, mark the edges of the blade. I marked a 45 degree chamfer, and during the sharpening process, when the marker disappeared, I knew for sure that the required sharpening angle had been reached.

- use different files, both coarse and fine, as some shoot a lot and with grooves, while others shoot smoothly, but the process is slow.

Step 4: heat treatment

As I mentioned, I don't have a forge, so I had to work hard to find a workshop where my sword would be tempered using the "differential hardening" method. This is an interesting method used by Japanese craftsmen to temper katanas. The bottom line is that the blade and the body of the blade are cooled in different ways, because the body of the blade is coated with clay, which slows down the cooling process. Thus, after heating and cooling, the blade becomes hard but brittle, and the body of the sword is soft and strong. Which is what you need for a great sword.

At least in theory.

Few of the connoisseurs of weapons are left indifferent by the Japanese sword. Some believe that this is the best sword in history, the unattainable peak of perfection. Others say that this is a mediocre craft that does not bear comparison with the swords of other cultures.

There are also more extreme opinions. Fans may argue that the katana cuts steel, that it cannot be broken, that it is lighter than any European sword of the same size, and so on. The scoffers say that the katana is fragile, soft, short and heavy at the same time, that it is an archaic and dead-end branch of the development of melee weapons.
The entertainment industry is on the side of the fans. In anime, movies and computer games swords of the Japanese type are often endowed with special properties. The katana can be the best weapon of its class, or it can be the mega-sword of the protagonist and / or villain. Suffice it to recall a couple of Tarantino films. You can also remember the ninja action movies from the 80s. There are too many examples to seriously mention.
The problem is that due to massive pressure from the entertainment industry, some people have a filter designed to separate the real from the fictional fails. They begin to believe that the katana is really the best sword, "because everyone knows it." And then there is a natural desire for the human psyche to support their point of view. And when such a person meets criticism of the object of his adoration, he takes it with hostility.
On the other hand, there are people who have knowledge of certain shortcomings of the Japanese sword. For fans who are uncontrollably praising the katana, such people often react with initially quite healthy criticism. Most often, in response - remember about the hostile reception - these critics receive an inadequate tub of slops, often infuriating them. The argumentation of this side also goes towards the absurd: the advantages of the Japanese sword are hushed up, the disadvantages are inflated. Critics turn into scandals.
This is how the incessant war goes on, on the one hand fueled by ignorance, and on the other - by intolerance. As a result, most of the information available about the Japanese sword comes from either fans or scolders. Neither one nor the other should be taken seriously.
Where is the truth? What is, in fact, a Japanese sword, what are its strengths and weaknesses? Let's try to figure it out.

Iron ore mining

The fact that swords are made of steel is no secret. Steel is an alloy of iron and carbon. Iron comes from ore, carbon from wood. In addition to carbon, steel can contain other elements, some of which affect the quality of the material positively, while others negatively.
There are many varieties of iron ore such as magnetite, hematite, limonite and siderite. They differ, in fact, in impurities. In any case, ores contain iron oxides, not pure iron, so iron from oxides always has to be reduced. Pure iron, not in the form of oxides and without a significant amount of impurities, is extremely rare in nature, not on an industrial scale. These are mainly fragments of meteorites.
In medieval Japan, iron ore was obtained from the so-called iron sand or satetsu (砂 鉄) containing grains of magnetite (Fe3O4). Iron sand is an important source of ore in modern times. Magnetite from sand is mined, for example, in Australia, including for export to Japan, where iron ore ran out long ago.
You need to understand that other types of ore are no better than iron sand. For example, in medieval Europe, an important source of iron was bog iron, containing goethite (FeO (OH)). There, too, there are many non-metallic impurities, and in the same way they need to be separated. Therefore, in the historical context, it is not too important which ore was used for the production of steel. More important is how it was processed before and after smelting.
The stumbling block about the quality of the Japanese sword begins with a discussion of the ore. Fans claim that satetsu ore is very pure and is used to make a very perfect steel. The scoffers say that in the case of mining ore from sand, it is impossible to get rid of impurities, and the steel is poor quality, with a lot of inclusions. Who is right?
Paradoxically, both are right! But not at the same time.
Modern methods of purification of magnetite from impurities, in fact, make it possible to obtain very pure iron oxide powder. Therefore, the same bog ore is commercially less interesting than black sand. The problem is that these cleaning methods use powerful electromagnets, which are relatively new.
The medieval Japanese either had to make do with cunning methods of cleaning the sand using coastal waves, or manually separate the grains of magnetite from the sand. In any case, if magnetite is mined and refined using truly traditional methods, pure ore will not work. There will be a lot of sand, that is, silicon dioxide (SiO2), and other impurities.
The statement "there was bad ore in Japan, and therefore the steel for Japanese swords is by definition of poor quality" is incorrect. Yes, there was indeed less iron ore in Japan than in Europe. But qualitatively it was no better and no worse than the European one. Both in Japan and in Europe, in order to obtain high-quality steel, metallurgists had to get rid of impurities that inevitably remained after smelting in a special way. For this, very similar processes based on forging welding were used (but more on that later).
Therefore, statements like “satetsu is a very pure ore” are true only in relation to magnetite, separated from impurities by modern methods. In historical times, it was dirty ore. When modern Japanese make their swords “in the traditional way,” they are disingenuous, since the ore for these swords is refined with magnets, not by hand. So these are no longer traditional steel swords, as the raw materials used are of higher quality. The gunsmiths, of course, can be understood: there is no practical point in using the obviously inferior raw materials.

Ore: conclusion

Steel for nihonto, produced before the industrial revolution came to Japan, was made from ore that is dirty by modern standards. Steel for all modern nihonto, even those forged in the most distant and authentic Japanese villages, is made from pure ore.

In the presence of sufficiently advanced technologies for smelting steel, the quality of the ore does not have of particular importance, since the impurities will be easily separated from the iron. However, historically in Japan, as well as in medieval Europe, such technologies did not exist. The fact is that the temperature at which pure iron melts is approximately 1539 ° C. In reality, you need to reach even higher temperatures with a margin. It is impossible to do it “on the knee”, you need a blast furnace.

It is very difficult to achieve a temperature sufficient to melt iron without relatively new technologies. Only a few cultures have been able to do this. For example, high-quality steel ingots were produced in India, and merchants were already transporting them all the way to Scandinavia. In Europe, they learned how to normally reach the required temperatures somewhere around the 15th century. In China, the first blast furnaces were built already in the 5th century BC, but the technology did not go outside the country.

The traditional Japanese cheese-blowing oven, the Tatara (鑪), was a fairly sophisticated device for its time. She coped with the task of obtaining the so-called tamahagane (玉 鋼), "diamond steel". However, the temperature that could be reached in Tatars did not exceed 1500 ° C. This is more than enough for the reduction of iron from oxides, but not enough for complete melting.

Complete melting is required primarily to separate unwanted impurities inevitably contained in conventionally mined ore. For example, sand, when heated, releases oxygen and turns into silicon. This silicon is trapped somewhere inside the iron. If the iron becomes completely liquid, then unwanted impurities like the same silicon simply float to the surface. From there, they can be scooped out with a spoon or left so that they can later be removed from the cooled ingot.

The smelting of iron in the Tatars, as in most similar ancient furnaces, was not complete. Therefore, the impurities did not float to the surface in the form of slag, but remained in the thickness of the metal.

It should be mentioned that not all impurities are equally harmful. For example, nickel or chromium makes stainless steel, vanadium is used in modern tool steel. These are the so-called alloying additives, the benefit of which will be at a very low content, usually measured in fractions of a percent.

In addition, carbon should not be considered an impurity at all when it comes to steel, because steel is an alloy of iron and carbon in a certain proportion, as noted earlier. However, when melting in Tatars, we are dealing not only and not so much with alloying additives of the type mentioned above. Slag remains in the steel, mainly in the form of silicon, magnesium, and so on. These substances, as well as their oxides, have become much worse in terms of hardness and strength characteristics. Steel without slag will always be better than steel with slag.

Smelt Steel: Conclusion

Steel for nihonto, smelted by traditional methods from traditionally mined ore, has a significant amount of slag. This deteriorates its quality in comparison with steel obtained with the help of modern technologies. If you take a modern one, pure ore, then the obtained "almost traditional" steel will be significantly higher quality than really traditional.

The Japanese sword is made from a traditional steel called tamahagane. The blade in different areas contains carbon in different concentrations. The steel is folded in several layers and has a zonal hardening. These are well-known facts, you can read about them in almost any popular article about the katana. Let's try to find out what this means and what effect it has.

To get answers to these questions, you will need an excursion into metallurgy. We will not go too deeply. Many nuances are not mentioned in this article, some points are deliberately simplified.

Material properties

Why are swords in general made of steel and not, say, wood or cotton candy? Because steel as a material has more suitable properties for making swords. Moreover, for the creation of swords, steel has the most suitable properties of all materials available to mankind.

Not so much is required of the sword. It should be strong, sharp and not too heavy. But all these three properties are absolutely necessary! An insufficiently strong sword will quickly break, leaving its owner unprotected. An insufficiently sharp sword will be ineffective in inflicting damage to the enemy and will also not be able to protect its owner. Too heavy a sword, at best, will quickly exhaust the owner, at worst, it will generally be unsuitable for combat.

Now let's take a closer look at these properties.

During use, swords are subject to powerful physical influences. What happens to the blade if you hit the target, whatever it may be? The result depends on what the target is and how to hit. But it also depends on the device of the blade with which we strike.

First of all, the sword must not break, that is, it must be strong. Strength is the ability of objects not to break from internal stresses arising under the influence of external forces. The strength of a sword is mainly influenced by two components: geometry and material.

With geometry, everything is generally clear: scrap is harder to break than wire. However, scrap is much heavier, and this is not always desirable, so you have to go for tricks that minimize the weight of the weapon while maintaining the maximum strength. By the way, you can immediately notice that all types of steel have approximately the same density: approximately 7.86 g / cm3. Therefore, weight reduction is achievable only by geometry. We will talk about it later, for now we will deal with the material.

In addition to strength, hardness is important for a sword, that is, the ability of the material not to deform under external influences. An insufficiently tough sword can be very strong, but it cannot stab or cut. An example of such a material is rubber. A sword made of rubber is almost impossible to break, although it can be cut - again the lack of hardness affects. But more importantly, its blade is too soft. Even if a "sharp" rubber blade is made, it can only cut cotton candy, that is, an even less hard material. When trying to cut at least wood, a blade made of a sharp but soft material will simply bend sideways.

But toughness isn't always helpful. Often, instead of hardness, plasticity is needed, that is, the body's ability to deform without self-destruction. For clarity, let's take two materials: one with a very low hardness - all the same rubber, and the other with a very high hardness - glass. In rubber or leather boots, dynamically curving after the foot, you can safely walk, but in glass, well, it will not work. A glass shard can cut through rubber, but a rubber ball will easily break window glass without getting hurt.

The material cannot simultaneously have high hardness and at the same time be plastic. The fact is that during deformation, a body made of a solid material does not change shape, like rubber or plasticine. Instead, it first resists, and then breaks, splitting - because it needs to put the deformation energy that accumulates in it somewhere, and it is not able to extinguish this energy in a less extreme way.

At low hardness, the molecules that make up the material are not too tightly bound. They calmly move relative to each other. Some soft materials take their original shape after deformation, while others do not. Elasticity is a property of returning to its original shape. For example, stretched rubber will gather back, unless you overdo it, and the plasticine will retain the shape that it will be given. Accordingly, rubber is elastically deformed, and plasticine is plastic. By the way, solid materials are more elastic than plastic: at first they do not deform, then they deform slightly elastically (if released here, they will return to their shape), and then break.

Varieties of steel

As mentioned above, steel is an alloy of iron and carbon. More precisely, it is an alloy containing from 0.1 to 2.14% carbon. Less is iron. More, up to 6.67% - cast iron. The more carbon, the higher the hardness and, at the same time, the lower the ductility of the alloy. And the lower the plasticity, the higher the fragility.

In fact, of course, everything is not so simple. You can get high carbon steel that is more ductile than low carbon steel, and vice versa. Metallurgy is much more than one iron-carbon diagram. But we have already agreed to simplify.

Steel containing very little carbon is ferrite. What is very little? Depends on various factors, primarily temperature. At room temperature this is about half a percent, but you need to understand that you should not look for excessive clarity in an analog world full of smooth gradients. Ferrite is close in properties to pure iron: it has a low hardness, deforms plastically and is a ferromagnet, that is, it is attracted to magnets.

When heated, the steel changes phase: ferrite turns into austenite. The easiest way to understand whether a heated steel billet has reached the austenite phase is to bring a magnet to it. Unlike ferrite, austenite is not ferromagnetic.

Austenite differs from ferrite in a different structure of the crystal lattice: it is wider than that of ferrite. Everyone remembers about thermal expansion, right? This is where it manifests itself. Due to the wider lattice, austenite becomes transparent to individual carbon atoms, which can travel freely within the material to a certain extent, ending up right inside the cells.

Of course, if the steel is heated even higher, until it is completely melted, then carbon will travel even more freely in the liquid. But now this is not so important, especially since with the traditional method for producing steel in Japan, complete melting does not occur.

When it cools, molten steel first becomes solid austenite and then turns back to ferrite. But this is a common case for "conventional" carbon steels. If nickel or chromium is added to steel in an amount of 8-10%, then upon cooling, the crystal lattice will remain austenitic. This is how stainless steels are made, in fact - alloys of steel with other metals. As a rule, they are inferior to conventional alloys of iron and carbon in terms of hardness and strength, so swords are made of "rusting" steel.

With modern metallurgical technologies, it is quite possible to obtain stainless steel comparable in hardness and strength to quality samples of historical carbon steel. Although modern carbon steel will still be better than modern stainless steel. But, in my opinion, the main reason for the lack of stainless swords is market inertia: customers of gunsmiths do not want to purchase swords from "weak" stainless steel, plus many value authenticity - despite the fact that this is, in fact, fiction, as discussed in the previous article ...

Getting tamahagane

Take iron ore (sattsu-magnetite) and bake it. We would like to completely melt it, but it will not work - the Tatars will not be able to cope. But nothing. We heat it up, bring it to the austenitic phase and continue to heat until it stops. Add carbon by simply pouring charcoal into the stove. Pour in the satets again and continue to bake. It is still possible to melt some part of the steel, but not all. Then let the material cool down.

As it cools, the steel tries to change the phase, turning from austenite to ferrite. But we've added a significant amount of unevenly distributed coal! Carbon atoms, freely moving inside liquid iron and normally existing inside a wide austenite lattice, during compression and phase change begin to squeeze out of a narrower ferrite lattice. From the surface, okay, there is where to squeeze out, just into the air - and good. But in the thickness of the material there is especially nowhere to go.

As a result of the transition of iron from austenite, part of the cooled steel will no longer be ferrite, but cementite, or iron carbide Fe3C. Compared to ferrite, it is a very hard and brittle material. Pure cementite contains 6.67% carbon. We can say that this is the "maximum pig iron". If carbon in some part of the alloy turns out to be more than 6.67%, then it will not be able to disperse into iron carbide. In this case, carbon will remain in the form of graphite inclusions without reacting with iron.

When the Tatara cools down, a steel block weighing about two tons is formed at its bottom. The steel in this block is not uniform. In those areas in which satetsu borders on coal, there will not even be steel, but already cast iron, containing a large amount of cementite. In the depths of satetsu, far from the coal, there will be ferrite. In the transition from ferrite to cast iron, there are various structures of iron-carbon alloys, which for simplicity can be defined as pearlite.

Perlite is a mixture of ferrite and cementite. Upon cooling and the phase transition from austenite to ferrite, as already mentioned, carbon is squeezed out of the crystal lattice. But in the thickness of the material, there is especially nowhere to squeeze it out, only from one place to another. Due to various inhomogeneities during cooling, it turns out that part of the lattice squeezes out this carbon, turning into ferrite, and the other part takes, turning into cementite.

When cut, perlite looks like a zebra skin: a sequence of light and dark stripes. Most often, cementite is perceived to be whiter than dark gray ferrite, although it all depends on the lighting and observation conditions. If there is enough carbon in the pearlite, then the striped areas will combine with purely ferritic ones. But this is all perlite too, just low carbon.

The walls of the furnace are destroyed and the steel block is shattered into pieces. These pieces are gradually crushed to very small pieces, examined meticulously, and, if possible, cleaned of slag and excess carbon-graphite. Then they are heated to a soft state and flattened to form flat bars of arbitrary shape, resembling coins. In the process, the material is sorted according to quality and carbon content. The best quality pieces of coins go to the manufacture of swords, the rest - anywhere. The carbon content is pretty straightforward.

Ferrite obtained from tamahagane is called hocho-tetsu (包 丁 鉄) in Japanese. Correct English notation is “houchou-tetsu” or “hōchō-tetsu”, possibly without a hyphen. If you search like “hocho-tetsu” you won't find anything good.

Perlite is exactly tamahagane. More precisely, the word "tamahagane" refers to both the entire steel produced as a whole and its pearlite component.

Hard cast iron from tamahagane is called nabe-gane (鍋 が ね). Although there are several names for cast iron and its derivatives in Japanese: nabe-gane, sentetsu (銑 鉄), chutetsu (鋳 鉄). If interested, then you yourself can figure out when which of these words is correct to use. Not the most important thing in our business, to be honest.

The traditional Japanese method of smelting steel is not very sophisticated. It does not completely get rid of the slag inevitably present in traditionally mined ore. However, it copes with the main task - obtaining steel. The output is small pieces of iron-carbon alloys, similar to coins, with different carbon contents. In the further production of the sword, various types of alloys are involved, from soft and ductile ferrite to hard and brittle cast iron.

Composite steel

Almost all technological processes obtaining steel for the production of swords, including Japanese, give the output of steel of various grades, with different carbon content, and so on. Some grades of steel are rather hard and brittle, others are soft and plastic. The gunsmiths wanted to combine the hardness of high carbon steel with the strength of low carbon steel. So, independently of each other, in different parts of the world, the idea of ​​producing swords from composite steel appeared.

Among fanatics of Japanese swords, the fact that objects of their veneration were traditionally made in this way, from "many layers of steel", is hailed as an achievement that distinguishes the Japanese sword favorably from other, "primitive" types of weapons. Let's try to find out why this view of things is wrong.

Technology elements

General principle: pieces of steel of the desired shape are taken, assembled in one way or another and welded by forging. To do this, they heat up to a soft, but not liquid state, and are driven into each other with a sledgehammer.

Assembly (piling)

The actual formation of a workpiece from pieces of material, most often with different characteristics. The pieces are forged welded.

Usually, rods or strips are used along the entire length of the product so as not to create weak points by lenght. But you can already collect it in different ways.

Random-structured assembly is the most primitive method in which pieces of metal of arbitrary shape are collected at random. Random-structured assembly is usually also random-compositional.

Random-compositional assembly - in such swords, it is not possible to identify a meaningful strategy for distributing strips of material with different contents of carbon and / or phosphorus.

Phosphorus was not previously mentioned. This additive is both beneficial and harmful, depending on the concentration and grade of steel. Within the framework of the article, the properties of phosphorus in alloys with steel are not of particular importance. But in the context of assembly, it is important that the presence of phosphorus changes visible color material, more precisely - its reflective properties. More on that later.

Structural assembly is the opposite of random-structural assembly. The strips from which the workpiece is assembled have clear geometric outlines. There is a certain intention in the formation of the structure. However, such blades can still be randomly compositional.

Composite assembly is an attempt to intelligently position different grades of steel in different areas of the blade - for example, having a hard blade and a soft core. Composite assemblies are always structural.

It should be mentioned which structures were usually formed.

The simplest option - three or more stripes are stacked, with the upper and lower stripes forming the surface of the blade, and the middle one - its core. But there was also its complete opposite, when the workpiece is assembled from five or more rods lying side by side. The outermost rods form the blades, and everything between them forms the core. Intermediate, more complex options were also encountered.

For Japanese swords, assembly is a very common technique. Although not all Japanese swords were assembled in the same way, not all of them were assembled at all. In modern times, the most common is the following option: the blade is hard steel, the core and back are mild steel, the side surfaces are medium steel. This variation is called sanmai or honsanmai and can be considered a kind of standard. Speaking in the future about the structure of the Japanese sword, we will have in mind just such an assembly.

But, unlike modern times, most historical swords have a kobuse structure: a soft core and back, a hard blade and side planes. They are really followed by swords of sanmai, then by a wide margin - maru, that is, swords are not made of composite steel, just solid. The rest of the cunning variants, such as the orikaeshi sanmai or sucki china, attributed to the legendary blacksmith Masamune, exist in homeopathic doses and are mostly just products of experimentation.

Folding

It is the folding in half of a fairly thinly flattened workpiece, heated to a soft state.

This element of technology, together with its manifestation from the next paragraph, is probably more publicized than others as the basis for the perfection of Japanese swords. Everyone has probably heard about the hundreds of layers of steel that Japanese swords are made of? So that's it. Take one layer, fold it in half. Two already. Once again, twice - four. And so on, in powers of two. 27 = 128 layers. Nothing special.

Faggoting

Homogenization of the material through multiple folding.

Bundling is necessary when the material is far from perfect - that is, when working with conventionally obtained steel. In fact, by "special Japanese folding" they mean exactly stacking, because it is precisely for cleaning from impurities and homogenizing slag that the blanks of Japanese swords are folded about 10 times. When folded tenfold, 1,024 layers are obtained, so thin that they seem to be gone - the metal becomes homogeneous.

Batching allows you to get rid of impurities. With each thinning of the workpiece, more and more of its content becomes part of the surface. The temperature at which this whole thing takes place is very high. As a result, part of the slags burns out, binding with atmospheric oxygen. Unburned pieces from repeated processing with a sledgehammer are sprayed in a relatively even concentration throughout the workpiece. And this is better than having one particular large slack somewhere in a certain place.

However, there are some downsides to bundling.

Firstly, the slag consisting of oxides does not burn out - it has already burned out. Such slag partially remains inside the workpiece, you cannot get rid of it.

Secondly, together with undesirable impurities, carbon burns out from steel during folding. This can and should be taken into account by using cast iron as a raw material for future hard steel, and hard steel for future mild steel. However, already here it is clear that you cannot batch endlessly - you get iron.

Thirdly, in addition to slag, iron itself burns, that is, oxidizes at temperatures at which folding and stacking takes place. It is necessary to remove the flakes of iron oxide that appear on the surface before folding the workpiece, otherwise a scrap will result.

Fourthly, the iron with each subsequent folding becomes less and less. Part burns out, leaving in oxide, and part just falls off from the edges, or needs to be cut off. Therefore, it is necessary to immediately calculate how much more material is needed. And it's not free.

Fifth, the surface on which the packaging is performed cannot be sterile, and neither can the air in the smithy. With each folding, new impurities enter the workpiece. That is, up to a certain point, batching reduces the percentage of pollution, but then begins to increase it.

Taking into account the above, it can be understood that folding and bundling is not some kind of super-technology that allows you to get some unprecedented properties from metal. This is just a way to get rid of material defects inherent in traditional methods of its preparation to a certain extent.

Why don't swords cast

In many fantasy films, the process of producing a sword is shown with a beautiful montage, usually for the main character or, conversely, for some evil antagonists. A typical picture from this montage: molten orange metal is poured into an open mold. Consider why this does not happen.

First, the molten steel has a temperature of about 1600 ° C. This means that it will not glow a soft orange, but a very bright yellowish-white color. In the cinema, some kind of alloys of soft and more low-melting metals are poured into molds.

Secondly, if you pour the metal into an open mold, the top side will remain flat. Bronze swords were indeed cast, but in closed forms, consisting, as it were, of two halves - not a flat saucer, but a deep and narrow glass.

Thirdly, in the movie it is meant that after solidification, the sword already has its final shape and, in general, is ready. However, the material obtained in this way, without further processing by forging, will be too fragile for a weapon. Bronze is more ductile and softer than steel, with cast bronze blades everything is fine. But the steel billet will have to be forged for a long time and persistently, radically changing its size and shape. This means that the blank for further forging does not have to be in the shape of a finished product.

In principle, it is possible to pour molten steel into the form of a workpiece with the expectation of further deformation from forging, but in this case, the distribution of carbon inside the blade will turn out to be very uniform or, at least, difficult to control - as much was in the frozen area of ​​the liquid, so much will remain. In addition, remember that in general, completely melting steel is a very nontrivial task, which was solved by few people in pre-industrial times. Therefore, no one did that.

Composite steel: lead

Technological elements for the production of composite steel are not something complicated or secret. The main advantage of using these technologies is to compensate for the shortcomings of the source material, which makes it possible to obtain a perfectly suitable sword from low-quality traditional steel. There are many options for assembling a sword, more or less successful.

Varieties of composite steel

Composite steel is an excellent solution for making a very high quality sword from mediocre raw materials. There are other solutions, but we'll talk about them later. Now let's figure out where and when composite steel was used, and to what extent is this technology exclusive to Japanese swords?

Quite a lot of samples of the ancients have survived to the present day. steel swords from Northern Europe. We are talking about a really old weapon made 400-200 years before our era. These are the times of Alexander the Great and the Roman Republic. In Japan, the Yayoi period began, bronze blades and spear points were in use, social differentiation appeared and the first proto-state formations arose.

Investigation of these ancient Celtic swords has shown that forging welding was in use even then. At the same time, the distribution of hard and soft material was quite varied. This was apparently an era of empirical experimentation, as it was not entirely clear which options were more useful.

For example, one of the options is completely wild. The central part of the sword was a thin strip of steel, on which strips of iron were riveted on all sides, forming the surface planes and the blades themselves. So yes, a hard core with soft blades. This can only be explained by the fact that the soft blade is easy to straighten with a hammer at a halt, and the hard core, made of steel with a still not too high carbon content, keeps the sword from deforming. Or that the blacksmith was not himself.

But more often Celtic blacksmiths simply stacked strips of iron and mild steel at random, or did not bother with layering at all. In those days, too little knowledge was accumulated to form specific traditions. For example, no traces of hardening were found, and this is a very important point in the production of a quality sword.

In principle, on the issue of the exclusivity of composite steel for Japanese swords, one could end here. But let's continue, the topic is interesting.

Roman swords

Roman writers scoffed at the quality of Celtic swords, arguing that their domestic ones were much cooler. Surely not all of these statements were based solely on propaganda. Although, of course, successes war machine The Romes were largely due not to the quality of their equipment, but to their overall superiority in training, tactics, logistics, and so on.

Composite steel was, of course, used in Roman swords, and in a much more orderly manner than in Celtic ones. There was already an understanding that the blade should be rather hard and the core rather soft. In addition, many Roman swords were tempered.

At least one of the blacksmiths, who worked around AD 50, used all the components of perfect composite steel in their production. He selected various grades of steel, homogenized them with multilayer beating, intelligently collected strips of hard and soft steel, forged it well into one product, knew how to harden and either applied tempering or hardened very accurately, without overdoing it.

The Yayoi period continued in Japan. About 700-900 years passed before the original traditions of the production of steel swords of the known Japanese type appeared there.

The traditions of the production of Roman swords, despite having all the necessary knowledge, at the beginning of our era were not perfect. There was a lack of a certain consistency, an explanation for the results of empirical observations. This was not an engineering job, but almost biological evolution with mutations and rejection of unsuccessful results. Nevertheless, taking all this into account, the Romans have been producing very high quality swords for several centuries in a row. The barbarians who conquered the Roman Empire adopted and subsequently improved their technology.

Somewhere between 300 and 100 BC, Celtic blacksmiths developed a technique called pattern welding. Many swords from Northern Europe have come down to us, made in 200-800 AD in Northern Europe using this technology. Patterned welding was used by both the Celts and Romans, and, later, almost all the inhabitants of Europe. Only with the onset of the "Viking" era, this fashion ended, giving way to simple and practical products.

Swords, forged with patterned welding, look very unusual. It's easy enough to figure out, in principle, how to achieve this effect. We take several (many) thin rods, consisting of various grades of steel. They can differ in the amount of carbon, but the best visual effect is the addition of phosphorus to some of the rods: such steel turns out to be whiter than usual. We collect this case in a bundle, heat it up and twist it into a spiral. Then we make the second same beam, but we launch the spiral in the other direction. We cut the spirals to parallelepiped bars, weld them with forging and give the desired shape by flattening. As a result, after polishing on the surface of the sword, parts of rods of one kind, then another - respectively, of different colors will come out.

But in fact, it is very difficult to do such a thing. Especially if you are not interested in chaotic striping, but in some kind of beautiful ornament. In fact, not just some kind of rods are used, but pre-packaged (folded and forged a dozen times) thin layers of assorted steel, neatly assembled into a kind of layer cake. On the sides of the final structure, rods of ordinary solid steel are riveted to form the blades. In especially neglected cases, several flat plates with an ornament were made, which were chained to the core of a blade made of medium steel. Etc.

It looked very colorful and joyful. Technical nuances that are not important to understand general essence, but there are a lot of things necessary for the production of a real product. One mistake, one metal element in the wrong place, one extra hammer blow, spoiling the drawing - and everything was lost, the artistic intention was ruined.

But one and a half thousand years ago they somehow managed.

Effect of pattern welding on the properties of the sword

It is now believed that this technology does not offer any advantages over conventional quality composite steel, other than aesthetic. However, there is one significant nuance.

Obviously, the creation of a sword decorated with patterned welding is much more expensive and time consuming than making just an ordinary sword, even if it has a full-fledged compositional assembly, but without all these decorative bells and whistles. So, this complication and rise in the price of the product led to the fact that the blacksmiths in the manufacture of weapons with patterned welding behaved much more carefully and thoughtfully. The technology itself does not bear any advantages, but the fact of its application led to increased control at all stages of the process.

To spoil an ordinary sword is not particularly scary, in production anything can happen, a certain percentage of marriage is permissible and inevitable. But to screw up a work that has gone into a blade with patterned welding is a shame. That is why pattern-welded swords on average were of better quality than ordinary swords, and the pattern-welding technology itself had only an indirect relationship to quality.

The same nuance should be kept in mind when it comes to any such sophisticated technology that magically improves the quality of weapons. More often than not, the secret is not in decorative tricks, but in increased quality control.

It's no secret that people often use certain words without understanding their meaning. For example, the so-called "Damascus" or "Damascus" steel has nothing to do with the capital of Syria. Someone illiterate once decided something for themselves, while others repeated it. The version “blades of this type of steel came to Europe from Syria” does not stand up to criticism, since you will not surprise anyone with steel of this type in Europe.

What is meant by "Damascus"?

In most cases - variations on the theme of patterned weaving. It is not at all necessary to stop at " puff pastry»Made of thin layers of steel with different content of carbon and phosphorus. Blacksmiths in different parts light have come up with a wide variety of ways to achieve a beautiful visual effect on the surface of expensive blades. For example, in modern times, when they want to get "Damascus", they usually do not use phosphoric steel and soft iron, since these materials are not very good. Instead, you can take normal carbon steel and add manganese, titanium and other alloying additives there. Steel, alloyed with an understanding of the matter and / or according to a competent recipe, will not be worse than ordinary carbon steel, but it may differ visually.

Speaking about the quality of weapons made from such steel, we recall the reasons for the high quality of swords with patterned welding. Expensive beautiful swords were made carefully and carefully. It would be possible to make the same high-quality sword from "ordinary" steel, without all these beautiful patterns, but it would be more difficult to sell it for a lot of money.

Bulat

There are probably no less legends associated with damask steel than with Japanese swords. And even more. Absolutely unthinkable properties are attributed to it, and it is believed that no one knows the secrets of its manufacture. An unprepared mind, when faced with such tales, becomes clouded and begins to wander dreamily, in especially difficult cases reaching ideas from the category "but I wish I could learn how to make damask steel and make tank armor out of it!"

Bulat is a crucible steel made in ancient times with the use of various tricks that allow you to bring the iron-carbon mixture to melt and not turn it into cast iron. Crucible - means completely melted in a crucible, a ceramic pot, insulating it from fuel decomposition products and other contaminants inside the furnace.

It is important. Damask steel, in contrast to "ordinary" steel, is not just somehow reduced from oxides by long baking, like the same tamahagane and other old varieties of steel from raw-blown ovens, namely, brought to a liquid state. Complete melting makes it easy to get rid of unwanted impurities. Almost everyone.

The iron-carbon diagram is indispensable here. All of it does not interest us now, we look only at the upper part.

A curved line running from A to B and then to C indicates the temperature at which the iron-carbon mass has completely melted. Not just iron, but iron with carbon. Because, as can be seen from the diagram, when carbon is added up to 4.3% (eutectic, "easy melting"), the melting point drops.

Ancient blacksmiths could not heat their stoves up to 1540 ° C. But up to 1200 ° C - quite. But it is enough to heat iron from 4.3% carbon to about 1150 ° C to get a liquid! But, unfortunately, when solidified, the eutectic mixture is completely unsuitable for the manufacture of swords. Because you will not get steel, but brittle cast iron, from which you cannot even forge anything - it just breaks into pieces.

But let's take a closer look at the process of solidification of liquid steel itself, that is, crystallization. Here we have a pot, closed with a lid with a small hole for exhausting gases. A molten mixture of iron and carbon splashes in it in a proportion close to eutectic. We took the pot out of the oven and left it to cool. If you think a little, it becomes obvious that the solidification will go unevenly. First, the pot itself will cool, then the part of the melt adjacent to its walls, and only gradually solidification and formation of crystals will reach the center of the mixture.

Somewhere near the inner wall of the pot, unevenness occurs and a crystal begins to form. This happens immediately at many points, but now we are worried about any one, any of them. It is the eutectic mixture that solidifies most easily, but the distribution of carbon in the mixture is not entirely uniform. And the hardening process makes it even less uniform.

Look at the diagram again. From point C, the melting line goes both to the right, to D - the melting point of cementite - and to the left, to B and A. When a certain area froze first, it can be assumed that it was the eutectic proportion that froze. The crystal begins to spread, "absorbing" the easily solidifying mixture with 4.3% carbon.

But apart from the eutectic regions, our melt also contains regions with a different proportion, more refractory. And, if we did not overdo it with carbon, then it would rather be more refractory regions with a lower carbon content than vice versa. Moreover: the solidified crystal "steals" carbon from the neighboring regions of the molten mixture. Therefore, as a result, the farther from the walls of the vessel, the less carbon will be in the frozen ingot.

Unfortunately, if you do everything as it is, you will still get cast iron, from which it is not possible to isolate possible small areas suitable for forging steel. But you can cheat further. There are so-called fluxes or fluxes, substances that, when added to a mixture, lower its melting point. Moreover, some of them, such as manganese, in a reasonable proportion are an additive that improves the properties of steel.

Now there is hope! And rightly so. So, we take the iron previously obtained in a cheese-blowing oven of the type of the same Tatars that everyone had in a row. We crush it as finely as possible. Ideally - bringing to a state of dust, but this is very difficult to achieve with ancient technologies, therefore, as it is. We add carbon to the iron: you can use both ready-made coal and not yet burnt plant mass. Don't forget the correct amount of flux. We distribute all this in a certain way inside the pot-crucible. How exactly depends on the recipe, there may be different options.

Using these and some other tricks, after melting and proper cooling in the central part of the crucible mass, the carbon content can be increased to 2%. Strictly speaking, it is still cast iron. But with the help of certain tricks, which it is absolutely unnecessary to talk about here, the ancient metallurgists obtained interesting crystal distribution structures in this 2% material, allowing, with certain difficulties and precautions, but still forging swords from it.

This is damask steel - very hard, very fragile, but much more durable than cast iron. It contains practically no unnecessary impurities. In comparison with raw steel such as tamahagane, yes, damask had certain interesting properties, and a specially trained blacksmith could create an impressive weapon out of it. Moreover, this weapon, like almost all swords from Celtic times, was composite, including not only crucible damask steel, but also good old strips of relatively soft material.

More sophisticated smelting processes, with the help of which the furnace can be heated to 1540 ° C and above, simply remove the need for damask steel. There is nothing mythical about it. In the 19th century in Russia, it was produced for some time, out of historical nostalgia, and then abandoned. Now you can also produce it, but no one really needs it.

Carolingian type swords, often referred to as Viking swords, were common throughout Europe from 800 to about 1050. The name "sword of the Vikings", which has become a common term in modern times, does not correctly convey the origin of this weapon. The Vikings were not the authors of the design of this sword - it logically evolves from the Roman gladius through the spatu and the so-called Wendel-type sword.

The Vikings were not the only users of this type of weapon - it was distributed throughout Europe. And, finally, the Vikings were not noticed either in the mass production of such swords, or in the creation of any particularly outstanding specimens - the best "Viking swords" were forged on the territory of the future France and Germany, and the Vikings preferred just imported swords. Imported, of course, by robbery.

But the term "sword of the Vikings" is widespread, understandable and convenient. Therefore, we will use it.

Pattern welding was not used in swords of this era, so compositional assembly became easier. But this was not degradation, but the opposite. Viking swords were made entirely from carbon steel. Neither soft iron nor steel with a high phosphorus content was used. Forging technologies had already reached perfection during the period of pattern welding, and there was nowhere to develop in this direction. Therefore, the development went towards improving the quality of the initial material - technologies for obtaining the steel itself were developing.

In this era, weapon hardening became widespread. Early swords were also tempered, but not always. The problem was the material. All-steel blades made of well-prepared metal could already withstand hardening according to some reasonable recipes, whereas in earlier times the imperfection of the metal could let the blacksmith down at the very last moment.

The Viking sword blades differed from older weapons not only in material, but also in geometry. The dale was widely used to make the sword lighter. The blade had a lateral and distal narrowing, that is, it was narrower and thinner near the point and, accordingly, wider and thicker near the cross. These geometric techniques, combined with more advanced material, made it possible to make a solid all-steel blade strong enough and light at the same time.

In the future, composite steel in Europe did not disappear anywhere. Moreover, from time to time a long forgotten patterned welding emerged from oblivion. For example, in the 19th century, a kind of "renaissance of the early Middle Ages" arose, within which patterned welding was even carried out firearms, not to mention the blade.

So what's in Japan? Nothing special.

Fragments of the future workpiece are stacked from pieces of steel with different carbon content. Then the preparation of this or that composition is assembled, it is given the desired shape. Next, the blade is hardened and then polished - we will talk about these steps later. Moreover, if we measure manufacturability, then according to the "technological level" of the material, damask steel makes everyone, including the Japanese. In terms of assembly perfection, patterned welding is no worse, if not better.

At the stage of assembling and actually forging a sword, there is no specificity that makes it possible to distinguish Japanese blades against the background of weapons of other cultures and eras.

Composite steel: another takeaway

Stacking of steel, allowing to achieve a homogeneous material with an acceptable amount and distribution of slag, has been used all over the world almost from the very beginning of the Iron Age. A well-thought-out composite blade assembly appeared in Europe no later than two thousand years ago. It is the combination of these two techniques that gives the legendary "multilayer steel", from which, of course, Japanese swords are made - like many other swords from all over the world.

Quenching and tempering

After a blade has been forged from one steel or another, work on it is not completed. There is a very interesting way to get a much harder material than ordinary perlite, from which the blade of a more or less perfect sword is made. This method is called hardening.

You've probably seen in the movies how a red-hot blade is dipped into a liquid, it hisses and boils, and the blade cools down quickly. This is hardening. Now let's try to understand what happens with the material. You can look again at the already familiar iron-carbon diagram, this time we are interested in the lower left corner.

For further hardening, the steel of the blade must be heated to an austenitic state. The line from G to S denotes the austenite transition temperature of conventional steel, without too much carbon. It can be seen that further from S to E the line grows steeply upward, that is, with an excessive addition of carbon to the composition, the task becomes more complicated - but this is almost in any case too brittle cast iron, so we are talking about lower carbon concentrations. If the steel contains from 0 to 1.2% carbon, then the transition to the austenitic state is achieved at temperatures up to 911 ° C. For a composition with a carbon content of 0.5 to 0.9%, a temperature of 769 ° C is sufficient.

V modern conditions it is quite easy to measure the temperature of the workpiece - there are thermometers. In addition, austenite, unlike ferrite, is not magnetite, so you can simply apply a magnet to the workpiece, and when it stops sticking, it becomes clear that this is steel in the austenitic state. But in the Middle Ages, blacksmiths did not possess either thermometers or sufficient knowledge about the magnetic properties of various phases of steel. Therefore, it was necessary to measure the temperature by eye in the literal sense of the word. A body heated to temperatures above 500 ° C begins to emit in the visible spectrum. By the color of the radiation, it is quite possible to approximately determine the temperature of the body. For steel heated to austenite, the color will be orange, like the sun at sunset. Due to these subtleties, quenching, including preheating, was often carried out at night. In the absence of unnecessary light sources, it is easier to determine by eye whether the temperature is sufficient.

The difference between the crystal lattices of austenite and ferrite has already been discussed in one of the previous articles of the cycle. In short: austenite is face-centered lattice, ferrite is body-centered. Taking thermal expansion into account, austenite allows carbon atoms to travel within its crystal lattice, while ferrite does not. It has also already been discussed what happens during slow cooling: austenite quietly transforms into ferrite, while the carbon inside the material disperses in strips of cementite, resulting in pearlite - ordinary steel.

And so we finally got to the hardening. What happens if you do not give the material time for slow cooling with the usual consumption of carbon for cementite strips in pearlite? Let's take, then, our billet, red-hot to austenite, and put it in ice-cold water, just like in a movie! ..

... Most likely the result will be a shattered workpiece. Especially if we use traditional steel, that is, imperfect, with a bunch of impurities. The reason is extreme stresses due to thermal contraction, which the metal simply cannot cope with. Although, of course, if the material is clean enough, then it is possible in ice water. But traditionally, they often used either boiling water so as not to lower the temperature too low, or even boiling oil. The temperature of boiling water is 100 ° C, oil is from 150 ° to 230 ° C. Both are very cool compared to the temperature of the austenitic workpiece, so there is nothing paradoxical about cooling with such hot substances.

So, let's imagine that everything is fine with the quality of the material, and the water is not too cold. In this case, the following will happen. Austenite, inside which carbon travels, will immediately turn into ferrite, while no separation into pearlite strips will occur, carbon will be distributed fairly evenly at the micro level. But the crystal lattice will turn out to be not regular cubic for ferrite, but wildly broken due to the fact that it is simultaneously formed, shrinks from cooling and has carbon inside.

The resulting type of steel is called martensite. This material, full of internal stresses due to the peculiarities of lattice formation, is more brittle than pearlite with the same carbon content. But martensite significantly surpasses all other types of steel in hardness. It is from martensite that tool steel is made, that is, tools designed to work on steel.

If you look closely at the cementite in the composition of perlite, you will notice that its inclusions exist separately and do not touch each other. In martensite, the crystal lines are intertwined like wires from headphones that have been in your pocket all day. Pearlite is flexible because areas of hard cementite dissolved in soft ferrite simply shift relative to each other when bent. But nothing of the kind happens in martensite, the regions cling to each other - therefore, it is not prone to change in shape, that is, it has a high hardness.

Hardness is good, but fragility is bad. There are several ways to compensate or reduce the brittleness of martensite.

Zone hardening

Even if the sword is tempered exactly as described above, the blade will not be entirely made of homogeneous martensite. The blade (or blades, for a double-edged sword) cool quickly due to their thinness. But the blade in the thicker part, be it the back or the middle, cannot cool down at the same rate. The surface is perfect, but the inside is no longer. However, this alone is not enough, anyway, a weapon hardened in this way without additional tricks turns out to be unnecessarily fragile. But, since the cooling is not uniform, then you can try to control its speed. And that is exactly what the Japanese have done with zone hardening.

A blank is taken - of course, already with the correct compositional assembly, a formed blade, and so on. Then, before heating for further hardening, the workpiece is coated with a special heat-resistant clay, that is, a ceramic compound. Modern ceramic compositions withstand temperatures of thousands of degrees in a solid state. The medieval ones were simpler, but the temperature is also needed lower. No exotic is required, it is almost ordinary clay.

The clay is applied unevenly to the blade. The blade either remains without any clay at all, or is covered with a very thin layer. The side planes and the back, which do not need to turn into martensite, on the contrary, are smeared from the heart. Then everything is as usual: heat and cool. As a result, the blade without thermal insulation will cool down very quickly, turning into martensite, and everything else will quietly form pearlite or even ferrite, but this already depends on the varieties of steel used in the assembly.

The resulting blade has a very hard blade, the same as if it were all made of martensite. But, due to the fact that most of the weapons are made of pearlite and ferrite, they are much less fragile. In the event of an inaccurate impact or upon collision with something excessively hard, a pure martensite blade can fly in half, because there are too many stresses inside it, and if you overdo it a little, then the material simply will not withstand. The sword of the Japanese type will simply bend, possibly with the appearance of a chipping on the blade - a piece of martensite will still break, but the blade as a whole will retain its structure. Fighting with a bent sword is not very convenient, but better than a broken one. And then you can straighten it.

Let's dispel the myth about the exclusivity of zone hardening: it is found on ancient Roman swords. This technology was generally known everywhere, but it was not always used, because there was an alternative.

Jamon

A distinctive feature of Japanese swords, made and polished in a traditional way, is the jamon line, that is, the visible border between different grades of steel. Professionals of zone hardening knew how and are able to make jamon of various beautiful shapes, even with ornaments - the only question is how to stick the clay.

Not every good sword, or even every Japanese sword, has a visible ham. It is impossible to see it without a specific procedure: a special "Japanese" polish. Its essence lies in the consistent polishing of the material with stones of various hardness. If you just polish everything with something very hard, then no jamon will be distinguishable, since the entire surface will be smooth. But if after that you take a stone that is softer than martensite, but harder than ferrite, and polish the surface of the blade with it, then only ferrite will be grinded. The martensite will remain intact, while the convex lines of the cementite may remain in the pearlite. As a result, the blade surface at the micro level ceases to be perfectly smooth, creating a play of light and shadows, aesthetically pleasing.

Japanese polish in general and ham in particular have no effect whatsoever on the quality of the sword.

Vacation and spring steel

Due to its structure, martensite has a large number of internal stresses. There is a way to relieve these tensions: vacation. Vacation is the heating of steel to a much lower temperature than that at which it turns into austenite. That is, up to about 400 ° C. When the steel turns blue, it is hot enough, the tempering has taken place. Then she is allowed to cool slowly. As a result, the stresses partially disappear, the steel acquires plasticity, flexibility and springiness, but loses its hardness. Therefore, spring steel cannot be as hard as tool steel - it is no longer martensite. And by the way, this is why overheated tools lose their hardening.

Spring steel is called spring steel because of the way springs are made from it. Its main distinguishing property is elasticity. The blade, made of high-quality spring steel, bends upon impact, but immediately returns to its shape.

Flexible, springy swords are monosteel - that is, they are composed entirely of steel, without the inserts of pure ferrite. Moreover, they are completely hardened to the state of martensite, and then completely tempered. If fragments not from martensite enter the structure of the blade before quenching, then the spring will not work.

A Japanese sword usually has such fragments: perlite along the planes and ferrite in the middle of the blade. In general, it is mainly made of iron and mild steel, there is not enough martensite there, only on the blade. So no matter how hard or let go of the katana, it will not spring. Therefore, the Japanese sword either bends and remains bent, or breaks, but does not spring, like a European monosteal blade made from loosened martensite. A slightly bent katana can be straightened without significant consequences, but it is not uncommon for pieces of a martensite blade to simply split off when bent, forming jagged edges.

The katana, unlike the European blade, does not undergo at least a complete tempering, so hard martensitic steel is preserved on its blade, with a hardness of a kind of 60 according to Rockwell. And the steel of a European sword may be in the 48 Rockwell region.

There are several traditional ways of forming the layered structure of a Japanese sword. Ferrite is not used in two of them. The first is maru, just solid high carbon steel all over the blade. Of course, such a sword requires local hardening, otherwise it will break at the first blow. The second is varikha tetsu, where the body of the blade, with the exception of the point, consists of steel of medium hardness, that is, of perlite.

Why were maru and variha tetsu not made springy? It is not known exactly. Maybe in Japan they did not know about the properties of steel tempering at all. Or they simply did not consider it necessary to make the swords springy. Do not forget that for Japan, even more than for the rest of the world, it was important to follow traditions. A significant number of variations in the design of Japanese (and not only) swords makes no sense from a practical point of view, pure aesthetics. For example, a wide fuller on one side of the blade and three narrow fullers on the other, or, in general, swords with asymmetric geometry at the cut. Not everything can and should be explained rationally, in relation to the battle.

Modern blacksmiths make Japanese-style swords with a spring blade and a martensite blade. The most famous American Howard Clark uses steel L6. The base of his swords is made of bainite, not perlite and ferrite. The blade is, of course, martensitic. Bainite is a steel structure not identified until 1920, it has high hardness and strength with high ductility. Spring steel is bainite or something close to it. With all the external similarity to nihonto, such a weapon can no longer be considered a traditional Japanese sword, it is much better than historical prototypes.

In a monosteal sword, you can also get differentiation by zones of hardness. If, after quenching, the martensite workpiece is tempered not evenly, but by heating only the plane of the blade directly, then the heat reaching the edges will be insufficient to transform the martensite blades into spring steel. At least in the modern production of knives and some tools, similar tricks are used. It is not known how the increase in the fragility of the blades of such weapons will affect in practice.

Which is better: high hardness without flexibility, or a decrease in hardness with the acquisition of flexibility?

The main advantage of a harder blade is that it holds the edge better. The main advantage of a flexible blade is its increased likelihood of surviving deformations. When hitting a target that is too hard, the katana blade is likely to break off, but due to the softness of the rest of the blade, the sword will not break, rather it will simply bend. A monosteel flexible blade, if it breaks, is usually in half - but breaking it with adequate use is very difficult.

Theoretically, hard steel should be able to cut through more materials than soft steel, but in practice, bones are normally cut with European swords, and no cutting sword can pierce the steel of armor anyway.

If we talk about working with a blade against plate armor, then no one will chop anything there: they will stab into the parts of the body that are not protected by armor, which are still covered at least with gambeson, or even chain mail. For thrusting, the very high flexibility of a spring blade is not suitable, but special European swords for fighting against plate armor were not flexible. On the contrary, they were provided with additional stiffening ribs. That is, special anti-armor swords have always been inflexible, no matter what steel they were made of.

In my opinion, in battle it is better to have a more durable sword that is difficult to spoil. It is not so important that it chops slightly worse than the harder one. A hard, zone-hardened blade can be more convenient in calm, controlled situations, such as tameshigiri, when there is enough time to aim and no one is trying to strike the sword from the weak side.

Quenching and tempering: conclusion

The Japanese possessed the hardening technology, which was also known in Ancient rome since the beginning of our era. There is nothing extraordinary in zonal hardening. In medieval Europe, they used a different technology to combat the fragility of steel, deliberately abandoning zonal hardening.

The blade of a Japanese sword is harder than that of most European ones - that is, it does not need to be sharpened so often. However, with active use, it is highly likely that the Japanese sword will have to be repaired.

Design and geometry

From a practical point of view, it is important that the sword is good enough. He must perform the tasks for which he was created - whether it be priority on the power of the chopping blow, improved thrust, reliability, durability, and so on. And when it's good enough, it doesn't really matter how it is made.

Statements like "a real katana should be made in the traditional way" are unfair. The Japanese sword has certain characteristics, including advantages. It doesn't matter how you manage to achieve these benefits. Yes, Howard Clark's Japanese-style bainite swords are not conventionally crafted katanas. But they are definitely katanas in broad sense the words.

It's time to move on to the more familiar aspects of the sword for discussion, such as blade geometry, balance, hilt, and so on.

Slashing Strike Effectiveness

The katana is renowned for being good at chopping objects. Of course, on the basis of this simple fact, fanatics are winding up a whole mythology, but we will not be like them. Yes, really - the katana is good at chopping objects. But what does this “good” mean in general, why does nihonto cut objects well, in comparison with what?

Let's start in order. What is “good” is a somewhat philosophical question, it emanates from it subjectivism. In my opinion, this is what makes good chopping qualities:

With a weapon, it is enough to simply inflict an effective blow, even a person without preparation will be able to cut a target of low complexity.
Cleavage does not require tremendous force and / or impact energy, it is based on the sharpness of the warhead and precisely on dividing the target into two parts, and not on breaking.
With proper operation, the weapon is unlikely to fail, that is, it is strong enough. It is desirable, of course, to have a margin of safety and not too correct operation. When the sword is worn like a written sack, it is not as impressive as when it is used to cut down a tree with a few careless blows.
The Japanese sword is really very easy to cut. The reasons will be discussed below, but for now, just remember this fact. Note that a significant portion of the mythologization of Japanese swords stems from it. For an inexperienced but diligent person, all other things being equal, it will be easier to cut a target with a katana than with a European long sword, simply because the katana is more tolerant of small mistakes. An experienced practitioner will not notice much of a difference.

For cutting itself, rather than tearing a target, you need to have a sufficiently sharp cutting edge. Here, the Japanese sword is all right. Sharpening by traditional Japanese methods is extremely perfect. In addition, a martensite blade, being sharpened, retains its sharpness for a long time, although this is more likely to refer to the next point. However, it should be noted that a sword, even without a martensite blade, can be sharpened and made very sharp. It will simply become dull faster, that is, it will need to be re-sharpened earlier. In any case, the number of blows after which the sword needs to be sharpened is measured in tens and hundreds, therefore, from a practical point of view, in a single episode, the hardness of a martensite blade does not give anything special, since two freshly sharpened swords will be used for a hypothetical comparison.

But with the strength of the Japanese sword, the situation is much worse than that of European counterparts. Firstly, from a sufficiently strong blow on an overly hard surface, the martensite blade will simply break off, leaving a notch on the blade. Secondly, with a combination of excessive force and low accuracy of the blow, you can bend the sword without any problems even when hitting a fairly soft target. Thirdly, the stresses inside the material are such that the Japanese sword still has a high strength when struck with the blade forward, but when struck in the back it has every chance of breaking, even if the blow seems very weak.

Voltage

To understand what stress is, let's conduct a thought experiment. You can also look at its schematic display in the illustration. Imagine a rod made of not very important material - let it be an elastic tree. Place it horizontally, secure the ends and leave the middle hanging in the air. A kind of letter "H", where the horizontal jumper is our rod. At the same time, the vertical columns are not fixed too rigidly, they can bend towards each other. (Position 1).

If we neglect gravity, which can be done, since the rod is very light, then the stresses we know in the rod material are small. They, if any, clearly balance each other. The rod is in a stable condition.

Let's try to bend it in different directions. The columns, between which it is fixed, will bend towards the rod, but if you release it, it will return to the starting position, pushing the columns to the sides. If we do not bend it too much, then nothing special will happen from such deformations, and, more importantly, we do not feel any difference between which way we bend the rod. (Position 2).

Now we will hang a significant weight from the middle of the rod. Under its weight, the rod will be forced to bend towards the ground and remain in this state. Now there is an obvious tension in our rod: its material "wants" to return to a straight state, that is, to straighten from the ground, in the direction opposite to the bend. But it cannot, the load interferes. (Position 3).

If you apply sufficient force in this direction, opposite to the load and corresponding to the direction of stresses, then the rod can be straightened. However, as soon as the effort is stopped, he will return to the previous flexed state. (Position 4).

If you apply a relatively small force in the direction of the load opposite to the direction of the stresses, then the rod may break - the stresses will have to break out somewhere, the strength of the material will no longer be enough. At the same time, the same or even much more powerful force in the direction of the stress direction will not lead to damage. (Position 5).

It's the same with the katana. The impact in the direction from the blade to the back goes in the direction of stresses, "lifting the load" and, one might say, temporarily relaxing the material of the blade. The impact from the back to the blade goes against the stresses. The strength of the weapon in this direction is very low, so it can easily break, like a rod on which a too large load is suspended.

Again the effectiveness of the chopping blow

Let's go back to the previous topic. Now let's try to figure out what, in principle, is needed to cut the target.

It is necessary to strike a correctly oriented blow.
The blade of the sword must be sharp enough to cut through the target, not just crush and move it.
It is necessary to give the blade a sufficient amount of kinetic energy, otherwise it will not be necessary to cut, but to cut it.
It is necessary to put enough force into the blow, which is achieved both by accelerating the blade and making it heavier, including through optimizing the balance for cutting, possibly even to the detriment of other qualities.

Blade orientation on impact

If you have ever tried tameshigiri, that is, chopping objects with a sharp sword, then you should understand what this is about. The orientation of the blade on impact is the correspondence between the plane of the blade and the plane of impact. Obviously, if you slap a plane on the target, it will definitely not be chopped, right? So, much smaller deviations from a perfectly accurate orientation already lead to problems. That is, when attacking with a sword, it is necessary to monitor the orientation of the blade, otherwise the blow will not be effective. With clubs, this question is not worth it, it doesn't matter which side to hit - but the blow will turn out to be shock-crushing, and not chopping-cutting.

In general, let's compare bladed and impact-crushing weapons without being tied to specific samples. What are their mutual advantages and disadvantages?

The advantages of the sword:

A slashing blow to an unprotected part of the body is much more dangerous than just a club. Although a club (a club with spikes) and a mace (a metal club with a developed warhead) do significant damage, the sword is still more dangerous.
Usually there is a somewhat developed hilt that protects the hand. Even a cross or tsuba is better than a completely smooth grip.
Geometry and balance, coupled with sharpness, allow the weapon to be made comparatively longer without overweight or loss of impact force. A knight's sword and a mace of the same mass differ in length by one and a half to two times. You can make a long light club, but a blow with it will be much less dangerous than a blow with a sword.
Significantly better stabbing capabilities.
The advantages of the baton:

Ease of manufacture and low cost. This is especially true for primitive clubs and clubs.
Developed varieties of shock-crushing weapons (mace, six-handle, war hammer) are specially sharpened for fighting opponents in armor. A knight's sword or long sword is significantly less effective against an armored man than a sixgun.
In the general case, excluding highly specialized war hammers and picks, it is easier to deliver a productive blow to a sufficiently close target with a baton or mace. There is no need to follow the orientation of the blade when hitting.
Let us again pay attention to the last of the listed advantages of shock-crushing weapons, which, accordingly, is a disadvantage of bladed weapons.

What can be said about the orientation of the blade when striking with a katana? That everything is fine with her.

A slight bend slightly increases the windage of the surface: leading a Japanese sword forward with a plane, and not with a blade or back, is a little more difficult than a straight blade of the same dimensions. Thanks to this wind resistance, the air resistance on impact helps the blade to turn correctly. For the sake of fairness, it should be noted that this effect is very weak and can easily be reduced to insignificance by applying the principle "there is power - no mind is needed." But if the mind is still applied, then one should first work with the Japanese sword through the air - slowly, then quickly, then slowly again. This will help you feel when he walks without any tangible resistance at all, cutting through the air, and when something slightly bothers him.

The Japanese sword has one blade, and the thickness of the blade at the back is quite large. These geometric characteristics, as well as the materials used in nihonto, increase rigidity, that is, "non-flexibility". Katana is a sword that does not bend as easily as its European counterparts, which at some point were generally made of spring steel (bainite) to increase strength.

The high rigidity coupled with the very hard blade leads to the interesting effect that makes katana felling so easy. It is clear that on impact, deviations from the ideal orientation are likely. If deviations are completely or almost absent, then the Japanese and European swords cut the target equally well. If the deviations are significant, then neither one nor the other swords will be able to cut the target, while the likelihood of spoiling the Japanese sword is higher.

But if deviations already exist, but they are not too large, then the Japanese martensite-ferritic and European bainite swords behave differently. The European sword will bend, spring and bounce off the target with little or no damage - as if the deflection were higher. In this case, the Japanese sword will cut the target as if nothing had happened. A blade that enters the target at an angle cannot spring and rebound due to its hardness and rigidity, so it bites in at whatever angle it can, and even corrects the orientation of the blade to some extent.

Once again: this effect works only for small errors. A bad blow would be better delivered with a European sword than a Japanese one - it is more likely to survive.

Sharpening the blade

The sharpness of the blade depends on the angle at which the cutting edge is formed. And here the Japanese sword has a potential advantage over the European double-edged sword - however, like any other one-sided blade.

Take a look at the illustration. It shows sections of the profiles of various blades. All of them (with obvious exceptions) can be inscribed in a 6x30 mm rectangle, that is, the blades in the place of cutting and analysis have a maximum thickness of 6 mm and a width of 30 mm. In the upper row there are cuts of one-sided blades, for example - nihonto or some kind of saber, and in the lower row - double-edged swords. Now let's delve into.

Look at swords 1, 2 and 3 - which one is sharper? It is quite obvious that 1, because the angle of its cutting edge is the most acute. Why is that? Because the edge is formed as much as 20 mm before the blade. This is a very deep sharpening and is rarely used. Why? Because this sharp blade becomes too brittle. Quenching the martensite will result in more than one would like to have on a sword designed for more than one strike. Of course, it is possible to correct for the formation of martensite by using ceramic insulation during hardening, but such a cutting edge will still be less strong than blunt options.

Sword 2 is already a normal, more durable option, which does not need to be worried about with every blow. Sword 3 is a very good, reliable tool. There is only one drawback: he is still rather stupid and there is nothing you can do about it. More precisely, you can do something, sharpening, but the reliability will just go away. With swords 2 and especially 1 it is good to cut targets in tameshigiri competitions, and with sword 3 it is good to train before competitions. It is hard in training - easy in "battle", where by battle is meant competition. If we talk about the battle on combat weapon, then sword 3 is again preferable, since it is much stronger than 2 and especially 1. Although sword 2, perhaps, can be considered something universal, but much more serious research needs to be done before such a statement.

The most interesting thing about sword 3 is the tapering lines of the blade indicated in blue, which are not yet a cutting edge. If they were not there, and the edge remained the same short, 5 mm, then its angle would be equal to 62 °, and not more or less decent 43 °. Many Japanese and other swords are made using such a narrowing, turning into a "dull" blade, as this is a great way to make a weapon at the same time fairly light, reliable and not too dull. A blade with an edge length of not 5, but at least 10 mm, as in sword 2, with the same narrowing to 4 mm at the beginning of the blade, will already have a sharpness of 22 ° - not bad at all.

Sword 4 is an abstraction, geometrically the sharpest blade in the given dimensions. Has all the problems of sword 1 in a heavier form. Sharp, yes, this cannot be taken away, but utterly fragile. It is unlikely that the martensitic-ferritic structure will withstand this geometry. If we take spring steel, then it may withstand, but it will become blunt very quickly.

Let's move on to the double-edged blades. Sword 6 is a Viking-type blade made in the above dimensions, having a flattened hexagon profile with valleys. The valleys do not have any effect on the sharpness of the blade, they are shown in the illustration for some integrity of the images. So, the sharpness of this blade corresponds to the one-sided sword 2. Which is not so bad. And even better is that historically Viking-type swords had completely different proportions, being thinner and wider - as can be seen from sword 7, which is as sharp as sword 1. Why is this so? Because instead of the martensitic-ferritic construction, other materials are used here. Sword 6 will blunt faster than sword 1, but it is less likely to break.

The disadvantage of Sword 6 is its very low rigidity - it is the most flexible of the blades presented here. Excessive flexibility interferes with a chopping blow, but you can live with it, but with a piercing it is generally useless. Therefore, in the late Middle Ages, the profile of the blade changed to a rhombic one, like that of sword 7. It is more or less sharp, although it does not reach swords 1 and 6. However, unlike sword 6, it is much less flexible. The maximum blade thickness of 6 mm makes it more rigid, which is great when thrusting. Compared to sword 6, in sword 7 there is an obvious sacrifice of the cutting ability in favor of the thrusting one.

Sword 8 has a pure thrusting blade. Despite the sharpness of 17 °, it will no longer work to cut with such a weapon. After penetrating the target to a depth of 13 mm, the impact will be inhibited by stiffening ribs that have an angle of as much as 90 °. But the mass of this blade is clearly less than that of sword 7, and the rigidity is even higher.

As a result, we have the following consideration: yes, a katana, in principle, can have a very sharp blade due to the geometry of a one-sided blade, which allows you to start sharpening or narrowing not from the middle, but from the back, while not losing rigidity. However, the martensite-ferritic blades of Japanese swords do not have sufficient strength properties to realize the maximum of what the geometry of a single-sided blade is capable of. We can say that the sharpness of the Japanese sword does not exceed the European one - especially when you consider that in Europe there were also one-sided blades, often from materials more suitable for sharp sharpening.

Kinetic energy

E = 1 / 2mv2, that is, kinetic energy linearly depends on the mass and quadratically on the impact speed.

The mass of a katana is normal, maybe slightly higher than that of European swords of the same dimensions (and not vice versa). Of course, despite the general external similarity, there are Japanese swords of very different masses, which is not visible in the pictures. But the katana is predominantly a two-handed weapon, so the increased mass does not particularly interfere with accelerating the blade to high speed.

Kinetic energy is not a question of the sword, but of its owner. If you have at least basic skills in working with weapons, everything will be fine. Here, the Japanese sword does not have any tangible advantages or disadvantages over its European counterparts.

Impact force: balance

F = ma, that is, the force linearly depends on the mass and on the acceleration. We've already talked about mass, but we need to add something about balance.

Imagine an object in the form of a weighty weight on a handle 1 meter long, a kind of mace. Obviously, if you take this object by the end of the handle farthest from the weight, swing it well and cut it with a weight accelerated at the end of the handle-lever, then the blow will turn out to be strong. If you take this object by the handle right next to the weight and hit with the empty end, then the impact force will be completely different, despite the fact that an object of the same mass is used.

This is because when struck with a hand weapon, not the entire mass of the weapon turns into force, but only a certain part of it. The balance of the weapon has a significant impact on what this part will be. The closer the balance point, the center of gravity of the weapon, to the enemy, the more mass can be put into the strike. M grows, and F grows.

However, swords with a balance close to the owner of the weapon, and not to the enemy, are usually called "well balanced". The fact is that it is much more convenient to fence with a well-balanced sword. Let's go back mentally to our weight on the handle. It is clear that with the first grip option, making high-speed and unpredictable movements with this weapon will be very problematic due to the monstrous inertia. In the second case, there are no problems, the massive mace will practically not have to be moved, it will only spin slightly near the fists, and it is not difficult to swing a light empty end.

That is, the optimal balance for felling and fencing is different. If you need to inflict damage, then the balance should be closer to the enemy. If maneuverability is required, and the lethality of the weapon is not fundamental or, in the case of modern non-lethal modeling, is undesirable, then it is better to have a balance closer to the owner.

The katana with the balance for the felling is all right. Nihonto usually have a very massive blade without the significant distal tapering typical of many European swords. In addition, they do not have a massive apple and a weighty cross, and these parts of the hilt very strongly shift the balance towards the wearer. Therefore, fencing with a Japanese sword is somewhat more difficult, since it feels heavier and more inertial compared to the European counterpart of the same mass. However, if the question of subtle maneuvers is not raised and you just need to chop powerfully, then the balance of the katana turns out to be more convenient.

Blade bend

Everyone knows that Japanese swords have a slight curvature, but not everyone knows where it comes from. Since the blade is cooled unevenly during hardening, thermal compression with it also occurs unevenly. First, the blade is cooled, and it immediately shrinks, therefore, in the first seconds of the hardening process, the blade of the future Japanese sword has a reverse bend, like kukri and other copies. But after a few seconds, the rest of the blade also cools, and it also begins to bend. It is clear that the blade is thinner than the rest of the blade, that is, there is more material in the middle and on the back. Therefore, in the end, the back of the blade is compressed more than the blade.

By the way, this effect just distributes the stresses inside the blade of a Japanese sword so that he holds the blow from the side of the blade normally, but from the side of the back no longer.

When quenching a double-edged blade, curvature does not appear by itself, because at all phases this process compression on one side is compensated for by compression on the other side. Symmetry is maintained, the sword remains straight. The katana can also be made straight. To do this, before hardening the workpiece, it is necessary to give a compensating back bend. There were such swords, although there weren't too many of them.

It's time to compare straight and curved blades.

The advantages of straight blades:

With the same mass, greater length, with the same length, less mass.
It is much easier and better to prick. Curved blades can be stabbed in an arc, but this is not such a quick and common action as a direct thrust.
A straight sword is often double-edged. If the hilt is not specialized for one direction of grip, then if the blade is damaged, it is easy to take the sword "backwards" and continue to fight.
Benefits of curved blades:

When applying a chopping blow to the lateral surface of a cylindrical target (and a person is a collection of cylinders and similar figures), the more curved the blade, the more easily the blow turns into a cutting one. That is, with the help of a curved sword, you can inflict a wounding blow, applying less force than is required for a straight sword.
On contact, the slightly smaller surface of the blade comes in contact with the target, which increases the pressure and allows you to cut through the surface. For the depth of penetration, this advantage does not matter.
Due to the slightly higher windage of the curved blade, it is easier to lead the blade forward, correctly orienting it upon impact.
In addition, both blades have specific fencing capabilities. For example, it is more convenient to hide behind a curved blade in some stances, and its concave back can in an interesting way affect the enemy's weapons. The straight blade has the ability to strike with a false blade and is somewhat more intuitive to control. But these are already details, one might say, balancing each other.

The following differences are significant: the advantage of straight blades in terms of mass / length, optimization of the application of pricks and, accordingly, the advantage of curved blades in the ease of applying an effective cutting blow. That is, if you just need to inflict damage with chopping and cutting blows, then a curved blade is better than a straight one. If you are more likely to fence in non-lethal simulation, where "damage" is taken into account very conditionally, then it will be more convenient to work with a straight blade. Note that this does not mean that a straight blade is a game-training weapon, and a curved blade is a real combat one. You can both fight and train, it's just that their strengths manifest themselves in different situations.

The Japanese sword usually has a very slight bend. Therefore, oddly enough, in a sense, it can generally be considered direct. It is quite convenient for them to prick in a straight line, although a rapier, of course, is better. There is usually no sharpening on the reverse side, but so it may not be with all sorts of broadswords. The mass - well, yes, it is quite large, and the sword is still with a chopping balance.

It is believed that a straight version of the Japanese sword would be better than traditional curved ones. I do not share this opinion. The argumentation of the defenders of this opinion did not take into account the main advantage of bending - the enhancement of the cutting ability of the blade. More precisely, I took it into account, but guided by the wrong premises. Even a slight bend of the sword already helps to deliver cutting-cutting blows with greater ease, and for a specialized cutting sword, which is a katana, this is exactly what is needed. At the same time, there is no particular loss of capabilities inherent in straight swords with such a slight bend. The only thing missing is a double-edged sharpening, but with it it would no longer be a katana. Although, by the way, some nihonto are sharpened one and a half, that is, the back on the first third of the blade is reduced to a cutting edge and sharpened - like late European sabers. Why this has not become the standard - I do not know.

Hilt

The Japanese sword has a very bad guard. Fanatics begin to shout “but the technique of work does not imply guarding, you have to fend off blows with a blade” - well, yes, of course it does not. Likewise, the absence of body armor does not imply a willingness to take a bullet in the stomach. The technique is as follows, because there is no normal guard.

If you take a katana and screw a kind of "tsubovina" with cue-like protrusions instead of the traditional, approximately oval tsuba, then it will already turn out better, it's checked.

Most swords have a much better guard than the Japanese. The crosspiece protects the hand more reliably than the tsuba. About a bow, a twisted hilt, a cup or a basket I am generally silent. Objectively, there are no significant shortcomings in the developed hilt.

You can name a couple far-fetched. For example, the price - yes, of course, a developed hilt is more expensive than a primitive one, but compared to the cost of the blade itself, it's a penny. You can also say something about the change in balance - but it will not hurt most of the Japanese swords, only it will become easier to fence with them. The words that a developed hilt will interfere with the performance of some techniques are delusional. If there are such techniques, then they can still be performed with a cross. In addition, the lack of a developed hilt interferes with the performance of a much larger number of techniques.

Why do Japanese swords, with the exception of a short period of imitation of Western-style sabers (kyu-gunto, end of XIX and the beginning of the XX century), did not a developed hilt appear?

First, I will answer the question with a question: why did developed hilts appear in Europe so late, only in the 16th century? They waved swords there much longer than in Japan. Briefly - they did not have time to think of it before, the corresponding invention was simply not made.

Secondly, traditionalism and conservatism. The Japanese saw European swords, but did not find it necessary to copy the ideas of these round-eyed barbarians. National pride, symbolism and all that. The correct sword in the understanding of the Japanese looked like a katana.

Thirdly, nihonto, like most other swords, is an auxiliary, secondary weapon. In battle, the sword was used in powerful gloves. In peacetime, when the katana just appeared from the more ancient tati - see point two. A samurai who thought of a developed hilt would not be understood by his fellow class members. You can figure out the consequences yourself.

Interestingly, after a short era of kyu-gunto, a constructively more advanced weapon than ordinary nihonto, the Japanese returned to the traditional type of swords. Probably, the reason for this was the same second point. A country with a growing unhealthy nationalism and imperialist manners could not afford to abandon such a significant symbol as the traditional form of the sword. In addition, in this era, the sword on the battlefield no longer solved anything.

Once again, the Japanese sword has a very bad guard. One cannot objectively object to this fact.

Design and geometry: conclusion

The Japanese sword has very good characteristics due to its design. It cuts targets perfectly and easily, and is more tolerant of minor impact imperfections. Chopping balance, martensite blade and blade curvature are an excellent combination that allows you to achieve very high results with a controlled impact.

Unfortunately, the Japanese sword also has a few notable flaws in its design. Tsuba protects the hand only slightly better than no guard at all. The strength of the blade when deviating from the ideal blow leaves much to be desired. The balance is such that it is not very convenient to fence with a Japanese sword.

Conclusion

If we consider a katana exclusively traditionally made Japanese sword, with all these inclusions in the tamahagana, with a martensite-ferrite blade and tsuba, then the katana is a very old and, frankly, rather flawed sword that does not withstand comparison with newer similar sharpened glands, which can perform all of its functions and even more. The katana is a weapon that is far from perfect, despite the high cutting properties of its blade.

On the other hand, a sword is like a sword. Chop is good, the strength is sufficient. Not perfect, but not complete crap either.

Finally, you can look at the katana from another side. In the form in which it exists - with this little tsuba, with a slight bend, with a ham visible during traditional polishing, with a stingray skin and a competent braid on the handle - it looks very beautiful. Purely aesthetically pleasing to the eye object that looks not too utilitarian. Surely, to a large extent its popularity is associated precisely with appearance... You should not be ashamed of this, people generally love all sorts of beautiful things. And the katana - in any form - is really beautiful.