Steel Comparison

Which Sword You Should Get?

For beginners who are just starting to collect and use Japanese swords one of the most commonly asked questions are what kind of steel are used on these swords. The next question is about the steel comparison between these blades. Before you make a purchase, ask yourself what you want the sword for?

If you think you might want to learn Japanese swordsmanship and want something useful – then you want an iaito (blunt sword) or shinken katana (sharpened sword) that can stand up to the rigors of real training. A functional samurai sword should stand up to a certain amount of abuse, keep a sharp edge, and be constructed correctly.

Shinken are functional katana swords made for real use. If you need a katana that will stand up to the rigors of real training in the dojo, or your backyard practice cutting, these are the swords that you should be looking at.
Iaito are used for practicing basic training such as swinging and kata (forms). They are not made for banging together or cutting anything. Iaitō are unsharpened practice swords with no cutting edge that are designed and manufactured much in the same way as Shinken. They are frequently made of materials other than steel.

Most functional samurai swords are made out of high carbon steel.  Most of them are high in carbon content. Some of the most commonly used high carbon steels are 1050, 1060 and 1095. As suggested by the number, a 1050 carbon steel has 0.50% of carbon content, a 1060 carbon steel has 0.60% carbon content, and a 1095 carbon steel has 0.95% carbon content. As carbon content rises the metal becomes harder and stronger but less ductile and more difficult to weld.

Steel can be heat-treated which allows parts to be fabricated in an easily-formable soft state. If enough carbon is present, the alloy can be hardened to increase strength, wear, and impact resistance. The purpose of heat treating carbon steel is to change the mechanical properties of steel, usually ductility, hardness, yield strength, or impact resistance.

Beside high carbon steels, there is another type of steel that is superior than high carbon steel in terms of hardness and durability. It is the T10 tool steel. Tool Steel has gained notoriety because of its toughness. All of the elements that make up T-10 made it stronger than other forms of steel having carbon content.

Folded or Non Folded.

Don’t confuse forged with folded because they are not the same. The folding process used for nihonto (traditionally made Japanese katana) is part of the refinement process for the steel. It produces a subtle hada (grain) in the surface of the blade. If you want a blade that has those characteristics – you want a folded blade. Folding does not improve the hardness or performance of the sword. It is mainly for artistic value. Also, folded blades are much closer to traditional nihonto and that is worth the price for many people.

Many production shinken are not folded. They are made from a single monolithic piece of steel. There’s no correlation between folded vs. monosteel swords and cutting ability, durability, or edge retention. The steel used and the tempering process are much more important for the functionality of the sword. The downside of folded blades is the possibility of weld failures between layers. Unless done correctly – the folded blade may be much less durable that a mono-steel equivalent. Everyone seems to want to know how many times the blade is folded. Some manufacturers make the number of folds a big selling point. You get 2 layers when you fold it once, 4 layers when you fold it twice (8,16,32,64,128,256,512,1024, etc…) You get 8192 layers if you fold the blade 13 times. You get a million layers if you fold it 20 times. However, it does not improve the sword.