The sword has a long history. For thousands of years, it was the primary weapon of the soldier, and it served as a basic tool of defense. It even became the symbol for war in many cultures. Firearms may have replaced the sword as the battlefield weapon of choice, but people still collect blades all around the world. Some people feel that any blade that comes into their possession needs to be capable of serving its primary purpose. These people take it too far and sharpen their swords too much. What can happen to over-sharpened swords?
It Cannot Cut Larger Objects
Knives, razors, and scalpels need to be razor sharp. They need to be razor sharp because these tools are designed to cut skin or hair, but they don't need to cut through armor, bone or any harder objects. A lot of the damage done by a sword is done by the weight put behind the force of a blow. The same principle is used in the ax and in the hatchet. Axes and hatchets are designed to bring down the weight of their head behind the blade. Someone who over-sharpens the blade can remove the sword’s heft. The Japanese sword makers referred to the same part of the sword as its meat. The edge of the blade may cut the skin, but a wielder wouldn’t be able to go deeper.
It Shortens the Life of the Sword
Routinely sharpening the edges weakens the blade. Although it’s unlikely that a modern user would take his sword into combat, sharpening the edges too many times removes metal from the sword. This makes the sword weaker. Although the owner can save the hilt for many years, he may find that he needs to replace the blade every few years or so.
Sword owners may want their weapon to have a working blade. Even people who want to only put it on display may feel that a sharp edge is necessary. Someone who wants to put the sword on display probably only needs to sharpen the blade one time. Most people who make swords for the modern world don't expect them to be used as a weapon, and many manufacturers deliberately send their products out with dull blades. If the weapon only hangs on someone’s wall, there’s no need for the manufacturer to go any further.