Why is this the best way to sharpen Japanese knives with whetstones?
We recommend that you use our whetstone (introduced on the maintenance page of this website) when you resharpen our knives. Our knives are designed with a convex shape (HAMAGURI). This shape is very fine. As you can see on the process page, we take many steps to form a shape that holds a sharp edge. This process is one of our outstanding techniques. We use several high-tech machines, as well as experienced handwork, to express this ideal shape.
In the beginning, the material starts as a flat form. Then, we grind the material to a rounder and thinner shape. This convex shape is very thin, but durable and sharp, and the curb line is very gradual. The reason why we recommend the use of whetstones is so you can control your sharpening gradually, step by step. And as you know, the whetstone surface is totally flat, so the fine edge can touch the surface in a precise manner, and finally, you can end up with a great edge. To achieve this result, you will need time to develop your sharpening skills. In addition, a convex shape is easier to resharpen. The reason for this is that there is no angle between the tip of the edge and the surface. We call it '2 (kanjI), or "second angle" in English. Some products with this type of edge can be seen in comparitively Western styles, as well as standard types. This is also one of the ways kitchen knives are produced. In this case, we recommend the use of a sharpening stick or grinder. Returning to the subject of the convex shape, it is our belief that this shape is always maintaining the form that can best be sharpened. For the novice, it usually takes about 20 minutes, but with time and practice, this time can be reduced to about 7 minutes, depending on what type of condition the knife is kept on a daily basis.
Below are 2 pictures of cross sections. On the left is a our knife with a convex style. On the right, is a knife with a second angle. Please compare them.
Convex style (You can see the fine edge line)
