What is the best steel for a kitchen knife?
The Science Behind a Blade - Different Qualities of Steel
How many times did you use a knife today? We probably use a knife every time we go into the kitchen and don’t even realize it. Whether it’s cutting an apple, chopping onions, crushing garlic, or peeling potatoes, there’s not much to do in the kitchen where knife doesn’t place an indispensable role.
What looks like a simple tool can do wonders. And it’s all possible with the blade of the knife. So what is the best steel for a kitchen knife? What makes a quality kitchen knife such a special tool? Do all knives have similar blades? Are all the blades the same shape and cut equally well? Do all the blades use the same kind of stainless steel in them? Let’s read on and learn a little more about the science behind the blade of the best kitchen knife. We've put together an overview for what we think is best knife steel chart for the purpose.
How does a blade cut?
How does the best kitchen knife make it effortless to cut all kinds of food items in the kitchen? What goes on at the anatomic level when you grab an onion and chop it with a knife? How are you able to make all those crisp thin slices from a whole onion? All the secrets lie within the blade. It’s not as simple as it seems.
So how does a blade make the cut?
Now the entire cut happens in the blink of an eye, but we’ll need to inspect it in slow motion to be able to understand what really goes on during that fraction of a second.
There are generally two types of cuts that go on in the kitchen. You either chop something or you slice it. Both types are slightly different in terms of the force that you apply and the angle at which you apply it. The blade will also perform differently for the two types of cuts. Let’s see what happens for both types:
When you chop an onion with your quality kitchen knife, you apply a force in the downward direction. You press the surface of the onion and in that fraction of a second, a trench will form on the onion skin under the blade, where you are applying the downward force. Microseconds later, that trench will split open under that force that’s being applied.
Now that a crack forms on the onion skin, the blade simply keeps moving downwards, opening up the crack and making way for its path. This is pretty much the same way in which an ax cuts down a piece of wood.
Slicing is different from chopping. Your purpose here is to make finer cuts to create thin slices of food. Unlike you do with chopping, you won’t apply a downward force here with the best kitchen knife. Instead, the blade is simply run across the surface of the food that you plan on cutting.
By driving the blade of your quality kitchen knife across the skin, you stretch the surface of the food item at the microscopic level. The food isn’t as resistant in the face of the stretching force that’s applied as it was during the compression force applied while chopping. This makes it a lot easier to rip open the skin of the food and results in a cleaner cut.
Slicing is only possible with a sharp knife since it will need a certain amount of friction between the knife and the food to rip open the skin. With a dull knife, you’ll need to apply a certain amount of downward force to press the food in order to make up for the lack of ample friction between the two surfaces.
Sharp vs dull: Which is safer?
Hard to believe? How could a sharp knife be safer? The best kitchen knife will be the one that has a sharp blade, among all the other superior qualities that are present.
● Dull knife
When you inspect a blade under the microscope, you’ll find that the dull knife has a round, smooth surface. This not only makes it difficult to rip open the skin of the food but also makes it dangerous for the user. How? It’s because the smooth surface of the blade means there isn’t going to be much friction between the blade and the food. This may result in the blade sliding off the food and piercing through your finger.
● Sharp knife
In contrast to a dull knife, a sharp knife has a sharp cutting edge that will allow lots of friction between the food surface and the blade. The overload of friction quickly brings about the rip. Once the first rip is made, only a little bit of downward force is sufficient to slice the food. There is absolutely no chance that your quality kitchen knife made out of stainless steel will slide off the food surface and onto your finger. The best kitchen knife with a sharp blade is the safest cutting option you could go for.
Different types of steel used for making the blade
The cutting quality of a kitchen knife isn’t just determined by the sharpness of the blade. The type of stainless steel or other materials that it uses also play a major role in determining how well or how poorly it’s going to cut. Know a bit more about the materials used in the making of the blade so that you can select the best kitchen knife for your kitchen:
● Carbon steel
Carbon steels are made using iron and carbon, in addition to a trace of manganese. The slight difference in the ratios of these elements used results in the difference in the name and performance. 10XX is the code used for high-carbon steel varieties. You can find different varieties ranging from 1045 to 1095 for the manufacture of the best kitchen knife.
Out of these, 1095 is the most popular one in use for this purpose for the excellent edge it offers. It has 0.95% carbon, which is higher than the content of carbon in 1045. The manganese content is lower in this variety. It’s not stainless steel and easily gets corroded. This is the reason why it’s usually accompanied by some form of coating to save it from rusting. Other than that, it’s tough and fairly easy to sharpen.
In contrast to 1095, 1045 uses lower carbon content (0.45%) and a bit higher manganese content. On the downside, the edge isn’t as great as it is for 1095.
Others from these series are also in use. 1060 and 1084 offer good edges too. 1050 is more common in swords than it is in a quality kitchen knife.
● Alloy steel
The 5160 steel is carbon steel that has been combined with a bit of chromium. It is actually 1060 carbon steel with the addition of just 1% chromium to make it harder. It one of the preferred varieties used in making swords, in addition to a quality kitchen knife because of the strength it offers.
● Tool steel
Tool steels are a combination of carbon and alloy steels that are especially suited for making tools. There are many varieties of tool steel.
A2 is strong steel which offers excellent resistance. It is not as resistant to wear as other varieties of tool steel. The chromium content is low (around 5%) while the carbon content is around 0.95 to 1.05%.
51200 is a high carbon tool steel that includes around 0.98 to 1.10% carbon which makes it strong and capable of holding an edge nicely. Just like A2, the chromium content is a bit low making it susceptible to rust. So you won’t find this material in a quality kitchen knife.
Crucible Particle Metallurgy produces a series of steels for making knives and other tools. CPM 3V is wear-resistant steel fashioned for toughness and hardness. CPM 10V and CPM M4 also exist. However, they aren’t very tough to qualify for the steel of the best kitchen knife.
D2 steel offers excellent resistance against wear. It’s somewhat tougher than stainless steel but still less wear-resistant in comparison to the stainless varieties. It holds an edge well but is not very easy to sharpen.
● Stainless steel
Stainless steel is characterized by its high chromium content. That’s where the wear resistance of stainless steel comes from. You’ll usually find a minimum of 12% chromium in most kinds of stainless steel used for making the best kitchen knife.
This steel lies between 60 – 62 HRC: Sharpness is about same as AUS 10 or VG10 steel and it's almost as brittle and easy to chip as the VG10. Edge retention is not as good as VG10 or AUS-10 steel. Rust and corrosion resistance also lacks in comparison. However it's a very good complement to VG10 in a Damascus steel blade which we at Eversharpe use it for.
The 420 stainless steel has a lower carbon content as compared to other varieties. About 0.38% carbon is included in this variety which makes it slightly softer than others and also lowers its ability to hold an edge. Rust resistance is excellent, on the bright side. A quality kitchen knife won’t use this material, though.
The 440steel comes in a range of varieties. 440A in inexpensive stainless steel with a carbon content of about 0.7%. It offers the most rust resistance in the 440 series. 440B isn’t much different from 440A. The only thing that’s different is the slightly higher carbon content, which is about 0.8% in this variety. 440C is one of the toughest varieties of stainless steel and a preferred material in making a quality kitchen knife.
425 is pretty similar to the 420 series, except that the carbon content is a bit lower at 0.5%.
154 CM Steel
With a high carbon content of 1.05%, this type of stainless steel isn’t just hard but very tough as well which makes it a popular material for a quality kitchen knife. As far as toughness is concerned, 154 CM Steel even beats the 440 series. It is one of the best varieties available; no wonder it’s sometimes called “super steel”. If you’re using the best kitchen knife, it may be made out of 154 CM.
ATS is Japanese made stainless steel that comes in two varieties. ATS 34 is similar to 154 CM. the only difference is in the manufacturer. 154 CM is made in America while ATS 34 is made in Japan. The carbon content is similar too, at about 1.05%. It qualifies as one of the best stainless steels available and a popular material used in the making of a quality kitchen knife.
ATS 55 is different from ATS 34 because it does not have vanadium in it. The carbon content is about 1%. ATS 55 isn’t as capable of holding an edge as ATS 34 and is also not as rust-resistant. So, if you’re using the best kitchen knife, chances are the blade wouldn’t be made out of ATS 55.
Steel for Eversharpe knives
The premium quality knives we present at Eversharpe have blades made out of the best quality steel. We use steel with a hardness at 54-56 HRC for some knife sets. Different varieties of knives available at our store.
How is it different from other steels?
The range 54-56 HRC is the ideal hardness for steel that’s preferred for kitchen use. It’s the steel of choice for many French chefs because of the durability and sharpness it offers. The sharpness of the blade makes it effortless to complete kitchen chores. Also, blades with steel in this hardness range are particularly simple to sharpen.
Steels with greater RCs value exist, but the higher level of hardness comes at a cost. While they have higher edge retention, the knife is also brittle and susceptible to cracks and breakage.
Measuring steel quality
Steel quality is measured in terms of multiple factors: hardness, corrosion resistance, edge retention, and ease of sharpness. While all the factors are highly important in dictating the worth of a knife, hardness is easily the most important one out of the lot. After all, it’s the knife’s ability to cut that will tell if it deserves a spot in your kitchen or not.
● Rockwell scale to measure hardness
Steel quality is measured on the Rockwell scale. The Rockwell test involves the application of different loads to check the hardness of steel and give value to it. Different standards of load applications are available and based on which different letters are denoted.
If you see HRA as the units of steel hardness, a 60 kgf force was applied to measure its hardness, HRB means 100kgf, while HRC means 150 kgf. Other scales are also used but HRB and HRC are the standards used most commonly.
● Test to measure hardness
The hardness test for steel will involve an indenter with a diamond tip that is pushed through steel under a large load to measure the depth it penetrates. This is compared to the depth of penetration under a small pre-load to determine the dimensionless RC value.
We started out with a question - What is the best steel for a kitchen knife? The correct answer is that it depends on the situation, the chef and the food. Boring answer. Possibly, but also pretty natural. As the steel of a kitchen knife should serve a purpose in supporting your everyday cooking. Eversharpe provides a range of different kitchen knives and kitchen knife sets. We carefully choose the ones we find that are best. The best steel for a kitchen knife is a very important part in our choice.