When buying a knife, it is certainly advisable to find out about the types of steel and choose one that meets your expectations of a knife. We have listed for you the most common steel types for kitchen knives.
Aogami / Blue Paper Steel
Literally, Aogami means “blue paper” in Japanese. It owes its name to the paper in which the manufacturer Hitachi packs the steel. It is a variant of white paper steel, a high-purity steel obtained from iron-rich river sand and containing only carbon as an alloying element. White Paper Steel is similar to the traditional Tamahagene steel from which Japanese swords were/are made, but is produced in a modern way.
Blue Paper Steel is White Paper Steel with the addition of small amounts of chromium and tungsten. This makes the steel a little less traditional, but it improves its properties. Blue Paper Steel is more corrosion and shatter-resistant than White Paper Steel, although it is certainly not stainless steel.
Blue Paper Steel is produced in 3 grades: #2, #1, and Super. For the Eden Kanso Aogami knives, “#2” is used with 1.2% carbon. This creates a hard (62-63 HRC) blade that can be sharpened to razor sharpness while still being extremely strong.
AUS-10 steel is produced in Tokai, Japan, by Aichi Steel. It is stainless steel because chromium, molybdenum, and vanadium have been added to it. This makes the steel stainless and wear resistant. With a hardness of 60 HRC, it is a very hard stainless steel with a high carbon content of about 1.05. However, due to the addition of elements such as nickel, manganese, and silicon, it does not break easily. AUS-10 is relatively easy to grind compared to other hard steels.
X50CrMoV15 is the most commonly used stainless steel grade for kitchen knives, among others by German manufacturers. It is a good steel for a very large audience. The corrosion resistance is very good, and the cutting properties are excellent.
Exceptional for use in the family and at work, where not everyone treats knives with the same care. For your information, X stands for stainless, 50 for 0.50% carbon, and 15 for 15% chromium. This addition of chromium makes the steel stainless. In addition, the steel contains small amounts of molybdenum (Mo) and vanadium (V) to improve grain structure and wear resistance.
1.4116 is a stainless steel with a high carbon content. This steel grade is used, among other things, for the well-known Swiss Army Knives and is almost identical in its properties to the steel X50CrMoV15. Excellent corrosion resistance, stays sharp for a long time, and is easy to sharpen yourself.
VG10 is a stainless steel with a high carbon content. At least for stainless steel. VG10 contains 1% carbon. This makes VG-10 harder than most stainless steel. The cutting properties are very good, and it is easy to sharpen it yourself.
Rust resistance is generally considered good, but VG10 steel is more susceptible to pitting corrosion than steels with lower carbon content. Once a rust spot occurs, it should be ground out or polished to prevent further corrosion. Regular sharpening of the blade will prevent corrosion that can cause parts to break out. Never put VG10 steel knives in the dishwasher or leave them in the sink. Softer steels are more forgiving in this regard.
VG10 steel is almost always laminated between two layers of softer and stainless steel. This increases corrosion resistance and simplifies the production process. Sometimes only layers of stainless steel are used, resulting in a 3-layer blade, and sometimes 16 or 32 layers of Damascus are used, resulting in a 33- or 65-layer blade. The manufacturer of VG10 steel is Hitachi, but the name Takefu, which sells the steel in laminated form, is also often used.
Another name for VG10 steel is “V-Gold 10.” Occasionally, the term “cobalt steel” is also used, but this can of course refer to any other type of steel containing cobalt. In addition to VG10 steel, there is also VG MAX. VG MAX has been further optimized with a higher chromium and vanadium content.
Cromova is Global’s name for the stainless steel they use. The steel consists of 0.8% carbon and the additions of chromium, molybdenum, and vanadium. Cromova steel has a fine-grain structure and can be sharpened to a very sharp edge. It combines good cutting properties with good corrosion resistance.
Friodur steel is a stainless steel grade mainly used by J.A. Henckels. Known from the Zwilling kitchen knives. The special feature of this steel grade is the heat treatment it undergoes. First, the steel is made very hot and then cooled. In this way, almost every knife is hardened. However, the Friodur steel is then cooled to -70°C degrees. This makes the knife even harder and more resistant to rust.
440A and 440C
440 steel is stainless steel with good corrosion resistance and excellent sharpness retention. With 440A steel, the main focus is on corrosion resistance. For 440C, on the other hand, the focus is on hardness. With proper heat treatment, 440C steels can achieve the highest strength, hardness, and wear resistance of all stainless steels.
440C and 440A are basically the same steels. The difference is in the carbon content. 440A has a carbon content that ranges from 0.60% to 0.75%. 440C has a high carbon content, ranging from 0.95% to 1.2%.
Sandvik 12C27 and 14C28N
Sandvik is a manufacturer of various stainless steel grades. The best-known steel grade is 12C27. This steel grade is used for the popular Morakniv knives, but Opinel, Laguiole and Aubrac have also been using it for years. This is because it is an easy-to-work steel with excellent corrosion resistance. It is not the hardest type of steel, but it is easy to sharpen yourself.
Sandvik 14C28N steel is similar to 12C27 steel but contains additional nitrogen and slightly more carbon. This makes the knife slightly harder and more wear resistant. In practice, you will hardly notice this difference.
Carbon Steel in general
Carbon steel by definition is steel with a carbon content of at least 0.05% to 2.1%. However, we often see manufacturers refer to anything that is not stainless steel as carbon steel. Carbon is the element that gives the knife its hardness. All other additives frequently make the steel more corrosion-resistant or tougher but at the expense of hardness. And the harder the blade, the thinner you can grind it and the sharper you can make it. However, this hardness is regularly accompanied by a high susceptibility to rust and brittleness. Perfect carbon steel is, therefore, a perfect balance between high carbon content and minimal additions of elements such as cobalt, molybdenum, or vanadium.
Stainless Steel in general
Stainless steel, or RVS, is a collective term for all steels with a carbon content of no more than 1.2% and a chromium content of at least 11%. The addition of chromium makes rust much less likely to occur. As described earlier, this addition of chromium affects the hardness of the steel. However, to make this steel suitable as knife steel, elements such as vanadium, molybdenum, titanium nitrogen, or silicon are added. This often makes the steel harder and more wear resistant.
A carbon steel kitchen knife and the care that comes with it is not for everyone. Therefore, choosing stainless steel is not a bad choice at all. Nowadays, there are stainless steel grades that are harder and more wear-resistant than certain carbon steels. Stainless steel kitchen knives are easier to maintain, but there is always the risk of rust.
Damascus steel is not actually a type of steel, but it has become very popular and is appearing more and more frequently in kitchen knives. Damascus steel is usually made of two different types of steel with different carbon contents. These two steels are forged alternately on top of each other. After forging, the blade is etched so that the high-carbon steel becomes dark. The low-carbon steel remains bright. This creates a beautiful contrast where all the layers are clearly visible.