You probably have seen katanas in movies, as cool weapons wielded by strong, mystical warriors. These deadly and beautiful swords seem to have an aura of magic about them. So, you may have asked yourself what are katanas made of?
What makes them so lethal and noble, at the same time? Is it the skill of the wielder? The mastery of the blade-smith? Or perhaps the strength of its steel?
Let’s answer that question … Let’s see what the most talented swordsmiths use to make katanas.
Real, fully-handmade models are expensive, not because of the steel of choice, but because of the long, grueling labor that a professional steel-smith needs to put. Imagine this … It can take up to six months for a traditional craftsman to make a unique samurai sword, with its own design and personality.
What are katanas made of? There are thousands of different steel alloy variants, each with their unique applications and uses, from jewelry to spaceships.
But a good sword needs the strongest variety, particularly if it’s as nimble and elegant as a katana. The edge needs to stay sharp, but the sword needs to be strong enough not to break. That would be a death sentence in a real fight.
Unfortunately, what keeps a sword sharp makes it brittle, at the same time. And what makes a sword strong, also allows its razor-sharp edge to blunt easily. I’m talking about steel. Specifically, about its carbon content.
Choosing the right steel is difficult because of that sharpness vs strength conflict. High-carbon steel keeps the blade sharp but makes it brittle. Such a katana could break on impact. However, low-carbon steel blades won’t shatter easily, but they will blunt more often.
The solution is to use various varieties of steel, to bind & fold them together, in a way that gives the katana all of the strengths and removes all the weaknesses. The result is folded steel.
What Is the Process of Folding Steel?
The steel used by traditional Japanese blade-smiths is known as tamahagane, which in Japanese literally means “jewel-steel”. The process of making this material starts with smelting iron-sand ore.
The tamahagane steel is created by combining pine tree or chestnut charcoal (for carbon) with iron and steel scraps (for iron), and putting it under fire. The charcoal provides the carbon which mixes with iron, to make tamahagane steel. Charcoal is used during forging, and also in the tempering process, albeit in smaller amounts.
The goal is to obtain several rods of steel of different hardness levels: soft, medium, and hard. These contain different carbon percentages.
These individual rods are reheated until they become more malleable. Then the smith hammers them into pliable sheets that can be folded one around the other. These sheets can be wrapped in the following way:
The soft steel rod is placed in a sheet of medium-hard steel. The craftsman hammers or folds the medium sheet around the soft steel rod.
Afterward, he can repeat the process by wrapping an even harder steel sheet around the newly forged soft/medium product. Basically, you get a thick steel rod that is a concentric layering of different types of steels. That metallic “stick” can be heated, hammered, tempered, and sharpened to make the katana. That is how they made folded-steel for the blade.
The inner-most soft layer provides a strong, durable spine, while the exterior hard steel layer helps maintain a sharp edge. There are several folding patterns (images below), depending on the type of sword that you want (and time, and budget):
Trans-sectional view. This is what a real katana is made of. Different layers of steel (of increasing carbon content) folded around each other, according to one of these patterns.
Some of these are very basic (less work and time, lower budget, and lesser quality). Others require a lot of skill, time, and money – but the sword is worth it!
The folded material is heated and cooled repeatedly to make sure that the individual steel rods and sheets bind together. That is the basic process.
If you ever wondered what are katanas made of, now you know. It’s just steel. Different types of steel, which the swordsmith folds, wraps, and binds, by repeatedly heating and cooling the blade.
Folding Patterns and Their Properties
The folding pattern (our last image) determines several qualities of the sword: durability, sharpness, visual aesthetics, color, price, how much effort does it take to produce it.
After the blade-smith makes the three varieties of tamahagane, he will then decide how to fold them. The three types of steel are classified by hardness:
HARD – High-carbon steel, which breaks on heavy impact. But it is not malleable or ductile, it can’t be easily manipulated and torn.
MEDIUM – Medium-carbon steel, which is sort of a trade-off between hard and soft. This option combines moderate durability with lesser edge-retention.
SOFT – Low-carbon steel, which is closer to iron in its qualities. It doesn’t shatter under stress, but it is easily bent and twisted. It prematurely loses its razor-sharpness.
I wrote how the swordmakers folded the layers, usually around a soft core (rod). Hammering thin sheets of red-hot steel is a dangerous and unforgiving task. No mistakes can be made! The last thing you want is a throw-away after months of work, and an angry samurai waiting for his sword.
A supremely good katana should contain all three steel varieties. They fold one around the other according to the more complex forging patterns above (Soshu Kitae, Orikaeshi Sanmai).
Why So Much Effort To Make a Katana?
Here is the logic behind the folded steel design. We want the katana to stay sharp and be strong enough so it doesn’t shatter on impact when hitting a sturdy target.
We know that hard steel keeps it sharp but makes it brittle. And that soft steel dulls out rather quickly but is durable. The solution is to fold those steels together in a way that give the blade the best of both worlds.
That means we want its edge to be of HARD steel so that it maintains sharpness. But we want the body strong and sturdy, so we make sure the inner layers are of SOFT and MEDIUM steels.
In the images above, you can see that the hard steel sheet (white) encloses the softer one. It forms the edge of the blade.
The simplest pattern katana (Maru) are forged from only one type of steel. Usually high carbon, like 1095 or 1085 (speaking about modern steel). These swords are very sharp but brittle and easy to shatter.
The best market katanas nowadays are still designed in single metal “Maru” pattern, but they use high-quality, industrial, superior steel like L6 Bainite or Spring Steel. I think these are as good as authentic folded steel Japanese blades.
The real Samurai swords (made by professional Japanese smiths) have intricate layers of all three steel variants. However, this requires hours of grueling work and master craftsmanship. The cost of such an item is several thousands of dollars.
How Do I Know If a Katana Is Of High Quality?
If you plan on buying a katana, chances are that you won’t be commissioning it from a Japanese master blade-smith. That lasts months and it costs thousands of dollars, up to 40 or 50 grand, in fact!
Luckily for you, there are sword manufacturers that produce very high-quality, battle-ready katanas. These blades are affordable, and we even made a list of top-rated katanas for the budget.
The mass-production of swords robs them of their personality. They need to be tough and of high quality, but at an affordable price. That means that your average katana won’t be forged according to the ancient Japanese techniques. It won’t be customized specially for you.
But don’t worry… What it lacks in personality, it makes up for in quality. Really good swords use the best industrial-grade, resistant steel that competes even with the traditional folded steel.
What Steel Are Modern Katanas Made Of?
With today’s technology, sword manufacturers are able to replicate the qualities of authentic Japanese swords. In fact, modern steel alloys vastly outperform their predecessors. Modern katanas are made from these materials:
Damascus steel. After gold and silver, this was the most precious metal in the Near East, a thousand years ago. It was used to make high-quality swords.
This steel alloy looks amazing and it is easy to identify, by its distinctive wavy patterns of banding and forging.
Damascus steel is tough, durable, and it keeps the sharp edge. It’s super-elastic and extremely hard. All the best qualities in one product. That means we don’t need to layer three steel variants to get this amazing result.
It is also known as “Damascus folded steel”. But don’t be confused, this method of folding has nothing to do with the Japanese tamahagane. It is a completely different process.
Spring steel. Hard but strong and bendy. Easy to sharpen but very difficult to shatter and chip. This steel is designed to take punishment.
We call it “spring” because it is used for making shock-absorbent coil springs for vehicles. It is much better than any regular carbon steel. The added silicon changes the molecular structure and adds new physical properties to the material: resistance to shock and stress, elasticity. It preserves the sharpness and hardness of CS steel.
Highly-resistant industrial steel. We have several industrial-grade alloys like T10 tool steel and L6 Bainite.
These are normally meant for the production of super-durable tools and cutters, like the ones they use in factories. Needless to say, these alloys are very strong, durable and not easily blunted. Perfect for making swords.
Mastering the Art of Blade-Smiting
Now you know what is a katana made from. We even went through the forging and folding processes. Sword-making is a skill mastery that took thousands of years to perfect.
From the blunt, jagged edges of worn-out copper axes of the Bronze Age, to the million-dollar masterpieces of legendary Japanese sword-smiths … We had enough time to learn to create the best blade at a minimum cost.
Nowadays, you can browse online and buy the best katana available, made from the most resistant steels, at the lowest prices. That’s every samurai’s wet dream!
Thanks to the artists for their amazing work: