Katana made from folded steel? Not always the best choice!

In this article, we explain why it is sometimes even bad when a sword is made of folded steel!

Why is the blade steel for samurai swords folded?

Folding serves to improve the properties of the traditional Tamahagane Stahls. Durch das Falten werden Verunreinigungen beseitigt und die Verteilung der Bestandteile innerhalb des Stahls wird mit jedem weitere Schritt gleichmäßiger, bis zur nahezu vollständigen Gleichverteilung (Homogenität).
With traditional steel grades, folded blades therefore have significantly better properties than blades that are not folded. With industrial mono-steel, folding tends to worsen the quality, as explained below.

How many times has the best katana been folded?

Üblicherweise wird der Stahl für die Klinge eines Katana ca. 10 bis 15 mal gefaltet. Der Stahl muss eigentlich nur so oft gefaltet werden, bis die inneren Bestandteile gleichmäßig verteilt sind. Bei jedem Falt-Schritt gibt der Stahl Kohlenstoffgehalt ab. Nach der Gleichverteilung wird nur noch gefaltet, um einen bestimmten Kohlenstoffgehalt zu erreichen. Wie oft der Stahl für eine Klinge gefaltet wird, ist vor allem von der Beschaffenheit des verwendeten Rohmaterials abhängig. Es gilt also keinesfalls die Regel, dass mehr Faltungen oder Lagen ein besseres Schwert ausmachen!

How many layers does a sword made of folded steel have?

The number results from the number of times the steel has been folded. To calculate the number of layers, the number 2 is multiplied by the number of folds.

Examples:
5x gefaltet: 2⁵= 32 layers
10x folded: 2¹⁰= 1024 layers
15x gefaltet: 2¹⁵= 32768 layers
20x gefaltet: 2²⁰= 1048576 layers

As explained above, the number of layers does not indicate the quality of the blade!

Does my sword have to be made of folded steel?

That's kind of the core question of the whole thing, and it depends above all on the steel used for production.

Traditionally produced Tamahagane steel should always be folded in order to achieve the improvements mentioned above. Standardised mono-industrial steel does not necessarily have to be folded, as folding does not result in any improvement. Similar to the Blade constructionWith this steel, less is more.

Folds on medium-priced swords

Medium-priced swords (everything up to approx. 2000 euros) are usually made of industrial mono-standard steel. A short list of examples of industrially manufactured steel grades can be found in this Article about steel grades.
Some sellers of these swords suggest that a blade made of folded steel is of higher quality than blades made of non-folded steel. But the exact opposite is the case!
Industrial monosteel has no impurities and is already largely homogeneous. Folding is therefore generally not necessary. Folding only reduces the carbon content of the steel and therefore the hardness.

If industrial steel is poorly folded, this can also reduce the quality of the blade (e.g. due to air pockets etc.)! In the case of standardised mono-steel, the rule of thumb is that a cleanly crafted, unfolded blade has better properties than a blade that is folded. Even if this steel is perfectly folded.
Before you buy a very cheap folded sabre made of industrial mono steel, we would recommend a sabre made of non-folded steel in this case in terms of quality!
Folded steel still has many fans, however, because folding can result in an attractive pattern. Of course, everyone has to judge for themselves how much this is worth.

So don't let false information take money out of your pocket unnecessarily.
You can find swords at reasonable prices in our Shop.