Honyaki and Kasumi
There are two types of Traditional Japanese knives based on the material and method used during the manufacturing: honyaki and kasumi. Each one has its advantages and disadvantages.
Kasumi means mist, fog and refers to the misty blade body appearance in contrast to the shiny carbon steel appearance. Kasumi knives are manufactured from the “soft” steel with carbon steel. After forging, hammering and Molding, the carbon steel becomes the blade edge. “Soft” steel becomes the body. If it were a sandwich, the carbon steel would be the filling and the soft steel would be the bread. This fusion reduces the risk of the knife breaking and makes it easier to sharpen. Althougth it is easier than honyaki to sharpen, the kasumi cutting edge durability is lower.
Honyaki is made from just one material. Its cutting edge durability is the greatest among Japanese knives. However, for being a very hard steel, if improperly handled, it may be broken or cracked. As it takes great skill from the crafstman to forge this material, the same works for the users of this knife type.