Steel types for kitchen knives
When you buy a knife it is recommended to inform yourself about steel types and choose a steel type that corresponds to your expectations of a knife. We have listed the most common steel types for kitchen knives.
Aogami / Blue Paper Steel - (not stainless) carbon steel
Aogami is Japanese for ‘blue paper’. Blue Paper Steel was named after the paper the manufacturer Hitachi packages steel in. It is a variable of so called White Paper Steel; a very pure type of steel usually found in iron-rich river sand, with only carbon as alloy. White Paper Steel is identical to the traditional Tamahagene steel used for the production of Japanese swords, but made in a modern way.
The carbon is mainly located in the crystal grid in this steel and hardly between the intersections between the crystals which benefits the quality. The steel also hardly contains flaws like sulphur that negatively impact on the quality of the steel, through the advanced production method. White Paper Steel is therefore a very pure type of steel.
Blue Paper Steel is White Paper Steel with the addition of small quantities of chrome and wolfram. That makes the steel slightly less traditional, but improves the characteristics. Blue Paper Steel is better corrosion and chipping resistant than White Paper Steel, although it definitely is no stainless steel.
Blue Paper is made in 3 gradations: #2, #1 and Super. For the Eden Kanso Aogami knives 'number 2' is used with 1.2% carbon. This provides hard (62-63 HRC) knives that can be sharpened razor sharp and still be particularly sturdy.
Available knives in this steel: Eden Kanso Aogami
Cronodur 30 - stainless steel
Cronodur 30 is stainless steel with a low carbon content and the addition of nitrogen. That benefits the resistance against corrosion while the hardness is good too. The steel promises a lot, but we have to say we have little feedback on these knives because we only carry one knives set in this steel type in our assortment.
Available knives in this steel: Zwilling TWIN 1731 series
D2 / SKD11 - Stainless powder steel
D2 and SKD11 are names for the same powder steel. Its fine structure and good distribution of the elements make it possible to add more alloy elements than in regular stainless steel. That increases the hardness and cutting characteristics. D2 / SKD11 steel is slightly harder than SG2 / SGPS steel but because of the lower chrome content less rust resistant too. It often is called a semi stainless steel type.
Like VG10 D2 / SKD11 steel is almost always used laminated.
Carbon steel HRC 60 - (not stainless) carbon steel
Rober Herder uses carbon steel hardened to the level of 60 Rockwell C. Hence the name HRC 60. This steel is hard at 60 Rockwell C hard, but not extremely hard. The carbon percentage is 0.8%.
Available knives in this steel: Robert Herder knives with the exception of the stainless steel knives.
MC66 / ZDP-189 - Stainless powder steel
ZDP-189 is called Zwilling J.A. Henckels MC66 steel and is the hardest stainless powder available at the time of writing (2012). It has the highest content of alloy elements of all powder steel types. Zwilling J.A. Henckels reaches a hardness of ca. 66 Rockwell C. ZDP-189 is very hard and durable, but more sensitive to corrosion and breakage of pieces than for example SG2 / SGPS and D2 / SKD11. In addition, ZDP-189 is difficult to sharpen.
Just like VG10 steel MC66 / ZDP-189 steel is almost always used laminated.
Available knives in this steel: Miyabi by Zwilling 5000MCD 67
SG2 / SGPS - Stainless powder steel
SG2 and SGPS are two names for the same powder steel. Its fine structure and good distribution of the elements makes it possible to add more alloy elements than in ordinary stainless steel. That increases the hardness and cutting characteristics. Nevertheless, the rust resistance of SG2 / SGPS is higher than that of VG10 steel.
Just like VG10 steel SG2 / SGPS steel is almost always used laminated. The damask steel used is always slightly harder than for VG10 knives, which benefits the scratch resistance.
Available knives in that steel: Eden Susumi.
VG10 (V-Gold 10) - stainless steel
VG10 is a stainless steel type with a - for stainless steel - high carbon percentage, i.e. 1%. This makes VG10 harder than most stainless steel types. The cutting characteristics are very good and VG10 is easy to sharpen razor sharp.
The rust resistance is overall good, but VG10 steel is more sensitive to pit corrosion than steel types with lower carbon content. When a rust spot occurs it must be ground/polished off to prevent that the corrosion continues. Regular sharpening of the edge prevents corrosion that can lead to breakage of pieces.
Never place knives in VG10 steel in the dishwasher and never leave them in the sink. Softer steel types are more forgiving.
VG10 steel is almost always laminated between 2 layers of softer and more stainless steel. That increases rust resistance and makes the production process easier. Sometimes pure stainless steel layers are used which results in a 3 layered blade and sometimes 16 or 32 layered damask is used which results in a 33 or 65 layered blade.
Another name for VG10 steel is 'V-Gold 10' The indication 'Cobalt steel' is sometimes used too, but that could of course also designate another steel type with Cobalt.
Hitachi is the manufacturer of VG10 steel, but often the name of the Takefu factory is used, that markets the steel in laminated format.
X50CrMoV15- stainless steel
X50CrMoV15 is the most commonly used stainless steel type for kitchen knives by a.o. German manufacturers. It is a good steel type for a very wide public. The rust resistance is high and the cutting characteristics are perfect.
Excellent for family use and professional use where not everyone is careful with the knives. For info: X stands for stainless, 50 for 0.50% carbon and 15 for 15% Chrome. In addition the steel contains small quantities of Molybdene and Vanadium to improve the grain structure and durability.
Available knives in this steel: Our Eden Essentials knives, all Wüsthof knives except Silverpoint, All knives by Zwilling J.A. Henckels (except 1731, Miyabi and Twin Cermax and the Damask knives) and Robert Herder RVS knives.
Other materials than steel
Attempts have been made for years to create the ultimate knife that never requires sharpening. Reality is different. We are yet to see knives that fulfil that promise. See also our article about ceramic knives.