About the authorThis article was written by Shinjiro Kida, a longtime professional in the Japanese knife industry with decades of experience working closely with Japanese knife makers, manufacturers, and retailers. He spent many years at Tojiro in the Tsubame-Sanjo region, where he was involved in the company’s international business and helped connect Japanese cutlery with customers around the world. He later established his own company specializing in the export of Japanese kitchen knives and culinary tools. Through his work, Shinjiro has gained extensive firsthand knowledge of Japanese knife making, its craftsmen, and the traditions behind the industry. |
After the Stone Age, people started using iron for making tools and weapons. But as cooking equipment, iron was not ideal enough. Compared to stone, although iron has better sharpness and can be processed easily, the problem of rust is not avoidable. Because of rust, a knife loses its sharpness and makes food taste bad.
In later years, a small amount of carbon was added, and conventional iron became carbon steel. Carbon steel is more resistant against rust and is also equipped with better sharpness and durability.
Carbon steel in general contains 0.2–2% carbon, but the best for cooking knives is said to be around 1%. For instance, 1.3% in Aogami #2, 1.45% in Aogami Super, 1.1% in Shirogami #2, 1% in Ginsan, and 1.5% in SLD.
Carbon steel made it possible to easily cut a wide variety of larger and harder ingredients.
Stainless steel has become a revolutionary material for knives.
Prior to its existence, iron was the only steel used for knife blades, but at the same time, it was the worst material for cooking because cutting ingredients containing acid causes iron to corrode and create rust. This can transfer a metallic taste to the ingredients.
Stainless steel, however, contains chromium. Chromium oxide covers its surface and helps prevent rust, so you do not have to worry as much about corrosion or the transfer of a metallic taste.
Eventually, this made it possible to preserve the flavor of ingredients and serve fresher, more delicious meals at home.
Sharpness, edge retention, hardness, maintenance frequency, and other factors should all be considered when choosing an appropriate steel for your knife. Here, we introduce some of the major steels used for knives.
First of all, steel can broadly be divided into two categories: carbon steel and stainless steel.
Carbon steel has better sharpness but rusts easily. Stainless steel, on the other hand, is less prone to rust and easier to maintain.
Generally, stainless steel is said to have less sharpness compared to carbon steel, but in recent years, stainless steel has evolved, and high-quality stainless steels with sharpness close to that of carbon steel have been developed.
Carbon Steel
Shirogami
High-quality steel commonly used for traditional Japanese knives. It has a very sharp edge with good edge retention and moderate toughness. It is also very sharpening-friendly.
There are two main classifications: Shirogami #1 and #2. Shirogami #2 is more commonly used due to its ease of handling.
Aogami
Also known as “Hitachi Blue.”
Based on Shirogami #2, with the addition of chromium and tungsten, its toughness and edge retention are remarkably improved. It is considered a premium version of Shirogami steel.
Like Shirogami, it is classified as #1 and #2, with Aogami #2 being more commonly used.
Aogami Super
Classified as one of the highest-quality carbon steels. It contains a very high amount of carbon and chromium. It is very hard and therefore provides good edge retention.
Stainless Steel
Molybdenum Steel
By adding molybdenum, the steel gains additional strength and toughness. Its price is also quite reasonable, making it an attractive option for many users.
VG-10
This very popular premium knife steel contains high concentrations of carbon, chromium, and cobalt. It provides excellent wear resistance, good edge retention, toughness, and rust resistance.
R2 or SG2
Also known as powdered high-speed steel. It contains carbon, molybdenum, vanadium, chromium, and tungsten, which make the steel remarkably hard.
Due to its hardness, it provides excellent sharpness and edge retention but requires a certain level of sharpening skill.
Gingami #3
Known as “Ginsan,” it contains 13% or more chromium. It provides excellent sharpness close to that of carbon steel and is easy to resharpen.
Common hardness: HRC 59 or higher.
It is a stainless steel but has characteristics similar to carbon steel.
ZDP-189
A high-quality powdered steel known for excellent sharpness. Its complete chemical composition has not been disclosed, but it contains very high amounts of carbon and chromium.
Common hardness: approximately HRC 67.
Conclusion
There are many different types of knife steel, each with its own advantages and characteristics. Carbon steels are valued for their sharpness and ease of sharpening but require more careful maintenance. Stainless steels are easier to care for, while modern powdered steels can provide excellent hardness and edge retention.
The best steel does not depend only on its hardness or price. It also depends on how the knife will be used, how often it will be sharpened, and how much maintenance the user is prepared to give it. Understanding these differences makes it easier to choose a knife that suits both your cooking style and everyday habits.
