The importance of iron quality in Japanese swords and knives

Japanese swords are beautiful works of art. Their elegant curves and refined details make them instantly recognizable.

When you look at a katana, you can't help but notice the wavy patterns on the blade.

These patterns come from folding the iron a lot of times — Far more work than European swordsmiths put into their blades.

So, you might think: "More work must mean better swords, right?"

Well, not exactly.

And the reason is pretty interesting.

Japanese swordsmiths had to work harder because they started with a big challenge: poor quality iron.

They didn't have a choice. They had to fold the metal many times to make it usable.

Japan's iron story: a tale of scarcity

Most of their iron came from "iron sand" found in rivers and mountains. And this iron sand was packed with impurities.

In contrast, Europeans could mine iron ore directly from the ground. Their iron was cleaner and easier to work with.

The numbers tell the story:

• European iron was about 98% pure.

• Japanese iron started at only 65% pure.

This big difference meant Japanese smiths had to work extra hard just to get to the same starting point as Europeans.

Japan could have imported good-quality iron... Except they decided to close off their country for hundreds of years.

So they turned this weakness into a strength — by developing really sophisticated ways to work with poor-quality iron.

How iron shaped armies

Because of these differences in iron, among other things, armies had different equipments which led to different needs for swords.

In Japan, samurai were the main warriors. They fought mostly one-on-one duels and wore light armor made of leather and lacquered wood. They used swords as backup weapons, because spears and bows came first in battle. They valued quick, precise cuts. And their battles were smaller and more personal.

In Europe, armies were large and professional. They fought in tight formations and wore heavy metal armor. Swords were primary weapons for many soldiers, and they needed weapons that could bash and thrust. Their battles involved thousands of soldiers.

It could almost be summarized like that:

• Less iron → lighter armor → focus on cutting techniques

• More iron → more metal armor → need for stronger swords

Making swords: two different paths

Of course, the difference in smithing also made the sword making processes different.

Japanese sword making:

• Folded steel many times (up to 16 times)

• Created layers with different hardness

• Made a hard edge but flexible core

• Had to be careful not to fold too much (could weaken the steel)

• Each sword took weeks or months to make

• Needed special care and regular maintenance

European sword making:

• Started with better steel, so less folding needed

• Could make longer, straighter blades easily

• Made swords with more uniform hardness

• Could make them faster and cheaper

• More durable in rough conditions

• Needed less maintenance

Modern Japan and iron: a new era

Japan used to be poor in iron. But that's ancient history now.

The country has become one of the world's biggest steel makers. They get the best iron ore from Australia and Brazil, and turn it into top-quality steel.

Their steel mills are some of the most advanced you can find.

And Nippon Steel stands tall as one of the largest steel companies in the world. They can make any type of steel they want, from basic to super-premium.

It's interesting to see how this affects Japanese crafts today.

By law, traditional swordsmiths still have to use old methods. But modern knife makers are free to work with new, high-quality steels.

That's why Japanese kitchen knives are so special.

They keep their traditional shapes, but they're made with modern materials.

Going further

Video about sword making

Video about Japanese swords vs European swords

Video about the different Japanese swords and how/when they were used

You can also find shop recommendations in other videos from this channel.

Sword museum in Tokyo

I recommend this museum for its architecture and garden, but it’s a bit expensive for its small size.

Better go to Tokyo National Musem, you’ll be able to see as many swords and many other things.