Japanese Knife Blade Steels

Blade Materials:

The materials used to make the blade-steel of Japanese knives, can be classified into two distinct categories.

 

Carbon steel: Most Japanese knives will fall under this first category. Carbon steel is made through the process of adding carbon to steel made from iron ore.

 

Stainless steel: Stainless steel is created much the same way as carbon steel, however chrome is added to the mix. The mixing of chrome with the steel prevents the material from rusting, thus making it a popular choice in kitchen knife construction. 

 

 

Knife Steel Characteristics:                                                                             

Steel Type  HRC  Sharpness Easy To Sharpen  Edge Retention 
(High Carbon) 
White #1 65+
White #2 60-61
Blue #1 65
Blue #2 63-65
Blue Super  63-64 
(Stainless)
VG10 60-61
VG1 58+
R2/SG2 64
ZDP189 66-67
AUS10 58-60
AUS8
58-60
Silver 3 59-61
- -
Comparisons
Wusthof  58
Henckels  55
Victorinox 		55-56

*HRC is a hardness scale based on the indentation hardness of a material

 

 

Steels:

Shirogami: Shirogami or white paper steel is the closest steel to the traditional tamahagane steel. The steel is very pure, in which it has very little impurities such as phosphorus and sulfur in the steel's make up. The steel does rust easily, however the edge it holds is regarded as one of the best. 

  • White #1 - has highest carbon content, having the hardest sharpest edge. May chip if used improperly however. has an HRC of 65+
  • White #2 - Mid range hardness, and is the most common type of white steel used. 60-61HRC

 

Aogami: Aogami or blue paper steel is basically shirogami steel with chrome and tungsten added to the steel. This is a very popular steel used in forging high end Japanese kitchen knives.

  • Blue #1 - Has best edge in terms of its sharpness. 65HRC
  • Blue #2 - Has most durable edge due to its hardness. typically between 63 - 65HRC
  • Blue Super - Aogami super is made by adding molybdenum and vanadium to the Aogami steel. Has the longest edge life of the blue steels and is a favorite among the craftsmen who make our knives. Typically it is hardened to 63-64HRC.

 

VG10: VG10 or V Gold 10, is a high quality cutting stainless steel. This steel is very hard and also very tough. Has great edge retention and is surprisingly easy to sharpen. Made by Takefu Special Steel Company, VG10 steel is a favorite by chefs for its balance as a hard working knife and durability in that its edge can withstand long shifts. Typically the steel has an HRC of 60-61.  

 

VG1:  A predecessor of VG10, VG1 is an amazing steel with much of the same qualities as VG10. The metallurgic content is a bit different however. HRC of 58+

 

R2/SG2: R2/SG2 is a high-carbon high alloy content stainless steel that has been powderized into a very fine grain and then sintered back together. This process allows for a very consistent gran structure in the steel which makes the blade easier to sharpen and very durable. The steel does not rust and will work great in fast paced kitchen environments. Has a 64HRC

 

ZDP189: A powdered steel, with high amounts of carbon and chromium added to the mix. Compared to other types of stainless steals it has a very high hardness and abrasion resistance. It is known for excellent corrosion resistance, great sharpness and excellent blade functionality. It is difficult to sharpen however, due to the hardness of the material. HRC is from 66-67

 

AUS10/AUS8: A very common, tested and tried stainless steel for kitchen knives. Is a great introduction steel to Japanese knives, in which, it is easy to sharpen, very durable, rust resistant, and is usually reasonably priced. AUS10 has better performance than AUS 8, better edge retention and holds a sharper edge. 

 

Silver 3:  Silver 3 is a fine grained high carbon content stainless steel with the cutting feel and ease of sharpening of a carbon steel. The cutting quality is similar to that of a shirogami steel. typically has an HRC of 59-61

 

BONUS!!!

Tamahagane: Tamahagane is a traditional type of carbon steel used to make knives and swords in Japan. The carbon steel was made using a tatara blast furnace. 

***Check out this awesome video of the creation of a tamahagane sword!