On the difference between the single and double edges of a knife

There are single- and double-edged types of traditional knives in Japan. Each of them has its own characteristics and benefits and disadvantages.
The characteristic of single-edged blade is that the flat surface behind the blade is hard steel and the sloped part on the front side of the blade is made of soft iron. Therefore, it becomes a sharp knife because the cutting edge is at a low angle.
The merit is that the sharpness of the blade is good. Because one side of the knife is flat, you can thin vegetables and fish. Peeling of fruits is easier than with double-edged blades. Suitable for cutting off branches of trees. And, since it is only necessary to sharpen the blade on one side, you can make the cutting edge sharp in a short time.
Disadvantages are that the blade may be chipped due to the thin edge of the blade, or it may become duller in an earlier time than a double-edged blade. Another point is that handling is difficult because the cutting edge advances diagonally when cutting food and so on.

The characteristics of the double-edged blade are made by sandwiching hard steel with soft iron.
The advantage is that the cutting edge has a high angle compared to a single-edged blade, so the sharpness can be kept for a long time. Also, it can be used by both left and right handed people and can be used in various applications. The double-edged blade is suitable for cutting food etc. in half because power is applied evenly to the left and right of the blade.
The disadvantage is that it is more difficult to slice or peel than a single-edged blade. In addition, it is more difficult to sharpen the blade than single-edged blades, and it takes time to sharpen the blade.

It takes experience to use a single-edged knife, but it is often used by professional cooks who want more accuracy and speed.
Single-edged knives are recommended for those who want to improve their cooking skills and those who are interested in Japanese food.