Carbon steel is an alloy of Carbon and Iron. For a steel to be categorized as high carbon steel, it must contain at least 0.5% Carbon in its composition. The Carbon content varies between 0.5 to 2.7%. Most Japanese high Carbon steel has more than 1% Carbon content.
In addition, high carbon steel contains small amounts of manganese, molybdenum, nickel, tungsten, vanadium, chromium, and cobalt, depending on the product and the manufacturer.
High Carbon steel knives have a high hardness of 60-65HRC. They are the best for cutting jobs that require high precision because they have a very sharp and fine edge and maintain the sharpness for a long time.
However, they are more brittle because of their lower toughness and rust easily. For the best performance, you must give high Carbon knives good care and maintenance. Ensure to wash and dry the blades after use.
Also, apply a coat of oil during storage to prevent oxidation. Additionally, do not use these knives for tough applications because they chip and break easily.
Note that all the high carbon steel types discussed here are non-stainless steel.
There are different types of high carbon steel out there, but we will concentrate on Japanese carbon steel knife types in this post. Come with me to the next section.
List of Japanese knife steel (types of high carbon steel)
Japanese knife makers source steel from various steel companies in Japan or other parts of the world. Most Japanese knives are made with either Shirogami (aka ‘white paper steel’) or Aogami (aka ‘blue paper steel) high carbon steel. Some Japanese knives are made from traditional Tamahagane steel.
White Paper Steel
White steel is high-end and very common knife steel in Japan produced by Hitachi. It is extremely pure steel and is used to make high-end steel knives and cutlery. White steel knives come in multiple grades, grades #1 and #2.
White steel #1 also known as Shirogami #1 steel
White steel #1 is made of pure and fine-grained Carbon with very few contaminants just like 26C3 steel (spicy white). It is high carbon steel with a hardness of 65 HRC plus. As a result, it holds an edge for the longest time but is the most brittle.
Forging a knife from White steel #1 is very difficult and can only be done by highly skilled knife makers. For this reason, knives made from this steel are very rare and expensive.
Also, using a knife made from this steel requires skill and tender care because they are very brittle and break easily.
White steel #2 also known as Shirogami #2 steel
The chemical composition of White steel #2 is similar to White steel #1 but, it contains lower amounts of Carbon but is still high carbon steel. It has a hardness of 60-61 HRC and is, therefore, less prone to chipping and breaking.
This steel offers a perfect balance between sharpness and brittleness, making it easy to use compared to White steel #1. Knives made from this steel are the most used and preferred by chefs.
Pros and Cons of White Steel (Shirogami Steel) Knives
- They are made of pure carbon steel alloy
- They have excellent cutting edge
- Have maximum edge retention ability
- They are easy to re-sharpen
- You can use them for delicate cuts
- The steel is not easy to forge
- They are volatile
- They are very reactive; hence stains and rust easily
- They are rare and expensive
Blue Paper Steel
Blue steel is also called Blue paper steel because of the blue paper wrapped around billets during manufacturing. Hitachi also manufactures it in Japan.
Blue steel is made from the same iron stock as white steel, and it contains high amounts of Carbon with few contaminants.
Blue steel differs from white steel because of the addition of tungsten and Chromium in its composition. These two elements give blue steel better edge retention and corrosion resistance than White steel, but it remains non-stainless steel.
The Blue paper steel is manufactured in three grades; #1, #2, and super high carbon steel
Blue steel #1 also known as Aogami #1 steel
Blue steel #1 has the same amount of Carbon as White steel #1 but with added Chromium and tungsten. It has a hardness of 61-64HRC as per the Rockwell hardness scale.
The added Chromium and tungsten give it better edge retention, sharpness, and corrosion resistance.
Blue steel #2 also known as Aogami #2 steel
Blue steel #2 has the same chemical composition as Blue steel #1 but has lower carbon content and as a result lower hardness. Because of its lower hardness is tougher and contains added tungsten and Chromium, which increase its durability and edge retention.
Super Blue steel is also known as Aogami Super steel
Super Blue steel is the most premium among Japanese high carbon steel types. Hitachi also manufactures it. It contains the highest percentage of Carbon and very minimal contaminants. With a hardness of 63HRC plus, it retains a sharp edge for the longest time.
Blue steel is mainly used to make traditional Japanese knives and takes a very thin and sharp edge. This makes them suitable for cutting delicate ingredients used in preparing traditional Japanese cuisine known as washoku.
Super steel differs from Blue steel #1 and #2 because it has more Carbon and extra amounts of Chromium, vanadium, tungsten, and molybdenum.
These additional components increase its toughness, corrosion resistance, and wear resistance—professional knife users rate knives made from this steel as the best on the market.
The only downside is that it is expensive, hard to sharpen, and easily rusts if not well taken care of. Furthermore, beginners are not advised to use Super Blue steel knives like the Usuba as they are very sharp and require extra care.
Pros and cons of Blue Steel (Aogami Steel) knives
- They have higher edge retention
- Excellent cutting and chopping for vegetables, fruits, and meat
- Suitable for cutting delicate ingredients
- Contain tungsten and Chromium
- Easy to sharpen
- Maximum toughness
- Their blades last longer
- Rust and stain quickly hence require extra care
White steel vs Blue steel
Both White and Blue steel are high in Carbon and are considered among the best steels for making kitchen knives. However, there has always been confusion on which steel makes the best knives.
Both steel types offer excellent cutting edges, and on the downside, they rust and stain without proper care, although Blue Steel is more corrosion resistant.
The choice between White steel knives and Blue steel Knives depends on your needs and budget. These Japanese knives are not the best when it comes to corrosion resistance, but their other features are worth the price.