One of our customers gave us a question, ” I am looking for non stainless, that is a full carbon knife. Is the honkasumi gyuto made of a mono steel or clad knife and what is the hardness of the steel?”
That is a good question, because there are two basic categories of traditional Japanese knives, Honyaki “true-forge” and Kasumi “mist”. These categories are defined by the forging method and material used in forging.
Honyaki knives are forged solely from one material: high-carbon steel (called “Hagane”). Genarally the Hagane is White steel(Shirogami) or Blue steel(Aogami).
The construction method used to make Honyaki knives is similar to that used to make traditional Japanese swords, which is a very difficult and long process.
After being heated treated, the steel is hammered repeatedly to form the shape of a blade and evenly distribute the carbon and chromium molecules. It requires the precise techniques of skilled and experienced craftsmen.
The blade of a Honyaki knife is hard, so it retains its sharpness for a long time; however, they are prone to chipping and difficult to sharpen. Since they cannot be mass-produced.
Honyaki knives are expensive, compared to other types of knives. They are primarily for professional chefs and are the highest quality traditional Japanese knives.
The following is one of the Honyaki knives,
“Sabun Honyaki (Tamashiro Steel) [with Saya]”
Kasumi knives are made from two materials by joining a piece of soft iron (Jigane) with a piece of high-carbon steel.
“Kasumi” means “mist” which refers to the hazy appearance of the soft iron body of the blade, as contrasted to the glossy appearance of the carbon steel.
The actual cutting edge and backside of the blade is carbon steel, while the supporting spine and rest of the blade is soft iron, which makes the sharpening process easier.
Kasumi knives are less expensive than Honyaki knives and are easier to use and sharpen.
In addition, Kasumi category has a higher grade, “Hon-kasumi” or “Hongasumi”. The hongasumi knives are made in the same way as Kasumi knives. But the quality of steel used is often higher, and more processes and work are required for its construction than Kasumi knives.
“Masamoto Honkasumi Tamashiro Steel”
“Sakai Takayuki Kasumi”
If you have any question, please feel free to contact us anytime.
Thank you for reading and best regards!
All the Hocho-Knife staff
“Hocho” represents Made-in-Japan (Sushi / Sashimi) Kitchen Knives,
that is the soul of the cook!