When choosing a Japanese kitchen knife, it is inevitable that its steel becomes a part of the consideration. There are a few kinds of steels that are commonly used in modern knife making, and I will cover some that are widely available in stores.
The types of carbon steels used in blades are categorized based on their makers. Yasugi factory, owned by Hitachi Metals, Ltd., is located in Shima-ne prefecture, Yasugi city. The steel produced there is not only limited to making the kitchen knives, but also carpenter’s planes, chisels and even high-end knives. The carbon steels named such as “Shirogami (White paper) #1” or “Aogami (Blue paper) #1” are mainly used in Japanese kitchen knife making.
Shirogami, Kigami (Yellow paper) are the carbon steels in which the impurities were reduced as much as possible. Aogami improves upon them by adding tungsten and chromium to achieve better heat-treating properties and toughness. Please see below for the detailed categorization based on the carbon content and others.
The kitchen knives made from such steels are used by the most of the professional cooks. There are cooks who are very particular about the number of the steel type when making purchases. These steels are well-known for the ease of sharpening.
If a black-smith makes blades from both Aogami and Shirogami steels, a wave-shaped Jiga-ne is likely used only with Aogami in order to distinguish from Shirogami blades.
When choosing a knife for home cooking, it is natural to think of stainless steels right away. The first and foremost advantage of stainless steels is their high rust resistance. Stainless steel knives are easy to maintain and can be used for a long time. On the other hand, they can be used daily even without proper maintenance — gradually the stainless steel blades get dull but still continue to be used — this can be said a pitfall of stainless steel knives.
Stainless steel knives can be purchased conveniently at home center or supermarkets. Although it seems easy to pick one up, there are actually a number of types of stainless steels. Professional cooks tend to make purchases accordingly.
In the case of stainless steel, Gin #1 and Gin #3 steels, produced by Hitachi Metal, and VG-10, produced by Takefu Special Steel are reputable steels suitable for kitchen knives.
High-speed steels used to be commonly applied as cutting tools material, but are now used to make knife blades. High-speed steels maintain its hardness even under high temperature. This property allows high-speed steels to cut faster than carbon steel if used on power-saw blades; hence the name. Such steel is hard but coarse in metal structure.
Powder steels are high-speed steels that are made in the way of powder metallurgy. This production method is fundamentally different from traditional steel making, and steels made this way have very fine metal structure and high toughness. These properties give powder steel blades sharp and long-lasting cutting edges, and made such knives popular among cooks.
It is worth noting that since powder steels are very tough, knives made with such material takes longer time to sharpen.
Ceramic blades can achieve great sharpness and never rust. It can be super light because it is not a metal. However, ceramic blades are easy to chip and should not be used against hard ingredients.
In the case of chipping, knives made from steels can be repaired at home with whetstones; but the ceramic knives have to be sent back to the manufacturer to be repaired with specific diamond sharpener.
- 包丁と砥石大全: 包丁と砥石の種類、研ぎの実践を網羅した決定版! 誠文堂新光社 (2014/8/19)
- Wikipedia https://en.wikipedia.org/wiki/High-speed_steel