I have been selling swords and knives for the past seven years, doing research and answering questions on the different types of swords and their uses. I’ve lived for six years in Europe and seven in the Orient and seen and held swords that are easier dated in centuries rather than years.
To keep it simple Functional kokushibo sword are made to be used and to keep an edge. However, to really answer this question you have to explain the three kinds of swords people sell. The first is a Decorative Sword. These are swords made to decorate and for display only. They are very elaborate and are sometimes heavy replicas of historical, fantasy and movie swords. They often come with a sword plaque or stand for their display in the home or office. The blades are made of stainless steel and are generally highly polished. They look really good but are not designed or made for use. The second is a Costume Sword. While they have many of the same characteristics of a decorative sword, they are generally lighter and come with a sheath or some means of wearing the sword with a costume. The last is the Functional Sword.
So What’s The Difference?
To keep it simple, quality is the thing that makes a functional or battle ready sword different. The quality of the materials, design and workmanship all play a part in a good functional sword. The materials are very important. High carbon steel is generally used to make the blades and other more durable materials are used for the guard, pommel and grips. High carbon steel is much harder. This type of steel is better suited for keeping an edge and less likely to break upon contact. The quality of the materials use in the guard, pommel and grip are of equal importance. A great high carbon steel blade with a pot metal or inferior guard and grip is a wall hanger.
Some people say the original design of a sword is the best. I agree. Swords were originally made for combat at the time they were designed and forged. Some like the samurai sword were designed to cut while others like the medieval claymore and long sword were made to bash and stab. The major design element is the tang. The tang is the part of the sword that attaches the blade to the guard, grip and pommel. Some decorative and costume swords use a rat-tail design. The blade is welded to the tang and not very durable. The best functional design is a full tang. Here the blade and tang are on piece of metal and less likely to break.
Workmanship may well be the most important. There are two basic ways to make a sword. They are machined and hand forged. The machined sword is almost entirely forged by a machine while the hand forged is done by a human. Purest say hand forged is the only way. However, I’ve seen many machined forged swords I feel more comfortable with. The key is micro-fractures. During the forging process sometime small fractures are left inside the sword. The more fractures there are the more likely the sword can break. There are many carbon steel swords not advertised as functional because of inconsistency. One sword might be great the next might not hold up. You take your chances when you buy these swords for use. One last note on design, a practical sword is made for stage plays and reenactments where safety is the key. Practical swords have rounded or dull edges and points.