The material of Japanese Cooker Knives

Yasuki-Hagane
We deal with cooker knives that are made from traditional Japanese steel called “Yasuki-Hagane,” which is a similar material to forge an authentic Japanese sword. That’s why traditional Japanese cooker knives “Wa-Bocho”(和包丁) is razor-sharp.
On the other hand, some companies developed particular metals, which is stainless. Some stainless knives are as sharp as Wa-Bocho.

“Yasuki-Hagane” is produced in Shimane Prefecture.
There are classes and ranks of steel depending on the amount of carbon and additives and how much impurity it contains.

Mainly five kinds of “Yasuki-Hagane” are used for making cooker knives.
These names are Shiro-kami 1st, Shiro-kami 2nd, Ao-kami 1st, Ao-kami 2nd and Ao-kami-super.
All Hagane have different characteristics; thus we recommend you to choose one for its use.

The main difference between the 1st and 2nd is how much carbon a blade contains in both Shiro series and Ao series.
The more carbon the knife contains, the harder it becomes. Less carbon means softness.

Shiro-kami series
Shiro-kami series is pure Hagane steels.
These Shiro-kami series are one of the most similar materials to that of a Japanese sword. This type of knife contains a lot of carbon, so it gets rusty easily and fast. Also, it needs constant maintenance and care. HRC61~63.

Shiro-kami 1st has most carbon in knives; therefore, it is hardest in Shiro-kami series. However, the knife loses its toughness and sharpness when not taken care properly. It is challenging to sharpen it to make the perfect blade shape again if you are not a trained whetter or chef.
You must not cut bones, frozen foods because the blade might get chipped. This knife is for professional chefs who know how to handle and maintain it.

Shiro-kami 2nd has lower carbon than the 1st. It is one of the favorite materials for making cooker knives because it is easy to handle and keep its sharpness. Also, the price is reasonable.
One disadvantage is easy to get rusty but compared to the 1st, you can whet it by yourself. We recommend this type of knife if you want to use it in your kitchen.

Ao-kami Series
Ao-kami series consists of carbon, chrome, and tungsten to get wearing resistance and easiness to forge in heat. Ao-kami is still regarded as steel however it is a new generation steel, compared to Shiro-kami series. It will not wear down as quickly as Shiro-kami series. Also, the sharpness will be kept longer than Shiro-kami series.
HRC64~67

Ao-kami super is the hardest material in the cooker knives we have. Therefore its sharpness and hardness will be kept for a However it’s super hard to whet to make a sharp edge.
This type of knife is a little hard to handle because of the reason above.

Ao-kami 1st contains less carbon than Ao-kami super, but it is still hard, however, much easier to make a sharp edge than Ao-kami super.

Ao-kami 2st is good to use in a kitchen of home as Shiro-kami 2nd.Easy to handle.

VG(V金)series.
Echizen Takehu, an edged tool-making company, developed this unique material called VG series.
It is stainless. However, the company used high-quality raw iron.
They add chrome, carbon, and cobalt to keep right balances between the materials in order not to get rusty as easily as Yasuki Hagane series, however still needs to be carefully maintained. HRC60 over