Harder steels have better resistance to wear. Softer materials are easier to gouge or scratch. Carbide hardness. Harder carbides, just like harder steel, are more resistant to wear. Here is a chart showing different steel carbide types with their range of hardness. Carbide volume fraction. A larger volume of carbides means better resistance to wear.
The carbides act like bricks in a brick and mortar road. More carbides means there is less wear to the overall steel.
Carbide size. Larger carbides mean better wear resistance when the abrasive is large and small carbides mean better wear resistance with fine abrasive or in sliding wear tests where two surfaces are rubbed against each other. Vanadium-alloyed steels are known for their high wear resistance because of the very hard vanadium carbides.
However, they do not show superior behavior in every wear test. For example, in a pin-on-table test reported in the S90V patent [2], D2 showed better wear resistance than S90V despite the high vanadium content in S90V. The D2 at 60 Rc lost The fact that vanadium carbide is much harder than garnet did not help it provide better wear resistance than D2.
In the patent they also reported the result of a crossed-cylinder wear test, where a cylinder of steel is worn on a cylinder of tungsten carbide. So the question is: which test better correlates with slicing edge retention? The crossed-cylinder wear test which shows S90V being an order of magnitude more wear resistant than D2, or the pin-on-table test that shows D2 as being slightly superior? Or neither? The edge geometry, including the thickness behind the edge, the angle of the edge, the sharpening of the knife, etc all affect the result.
One very strong controlling factor for cutting ability and edge retention is edge angle, which was shown in the earlier CATRA article , with a secondary effect of thickness behind the edge:. Changing Edge Angle with the same thickness behind the edge. Changing thickness behind the edge with the same edge angle. Higher sharpness increases cutting ability.
Lower edge angle or thickness behind the edge increases cutting ability independent of sharpness. You can read more in this article on sharpness vs cutting ability. So while the cutting ability is reduced throughout the test by a reduction in sharpness, it is not actually measuring sharpness.
This is important when comparing tests with different edge angles as the cutting ability is different independent of sharpness. A major knife company with a CATRA tester recently agreed to send me a large amount of their test data. They performed tests on a wide range of steels, including, but not limited to:.
There is a dizzying amount of data and not all of the tests can be easily compared with each other. All of the test reports include the steel type, most of the tests included the edge angle that it was sharpened to, about half of the data includes the hardness of the steel, some of the tests included the sharpening procedure such as the grit of the sharpening medium , and none included measurements of the thickness behind the edge.
They have been using a standard test mule and sharpening procedure since March which makes recent data more consistent. Similar to the previously published CM study, a strong effect of edge angle was also seen in this broad set of tests:. It is apparent that the difference between the high wear resistance and the relatively low wear resistance steels increases with lower edge angles.
As discussed earlier, the volume fraction of carbide is important for overall wear resistance. Unfortunately, the volume and type of carbides present in a heat treated steel is not always known.
In many cases there are values reported in different journal articles or datasheets but this is often for only one heat treatment. I used all values of which I am aware for the steels that were tested from a variety of sources [3,]. It is also possible to calculate carbide fractions with Thermodynamic software like JMatPro or ThermoCalc but I have restricted this article to the discussion of experimentally reported carbide content.
Or, you can just ask a pro which is also what we did. According to the World Steel Association , over 1. There are three levels of carbon steel; low. Carbon steel, although very strong, is more dull and prone to corrosion. Alloy steels are often used in electronics, pipes, or auto parts.
Tool steel is used for precisely what it sounds like, tools. Tool steel is incredibly hard and heat resistant thanks to the inclusion of durable elements like tungsten, molybdenum, cobalt, and vanadium. Many of these factors are reliant upon one another. However, some qualities must be given up for others in their chemical composition when developing particular steel.
For instance, when crafting stainless steel, some of the carbon needed for hardness must be given up for elements that contribute to non-corrosiveness, like chromium. The first thing that comes to mind when you think of a knife is its sharpness.
After all, its primary purpose is to cut through materials quickly and effectively. A precise combination of strengthening elements, combined with naturally malleable iron, allows for excellent sharpness and edge retention. To understand hardness in steel, you should familiarize yourself with the Rockwell Hardness Scale , which is used to classify hardness in steel. Very high carbon steel combined with elements like manganese will make the steel very hard yet brittle.
Elements that rank mid-range on the Mohs Scale of Mineral Hardness, like nickel, will add toughness to the steel. Sporting and combat knives with shorter, thicker blades typically have high ratings in the hardness and toughness departments.
Hardness and wear resistance go hand in hand because steel with high levels of carbides carbon are more wear-resistant, and high carbon steel is some of the hardest. But, a knife that is too hard will chip or break, and for it to be able to perform, it has to have elements within the steel that make it tough. Any steel can rust under the right conditions. Yet, steel with high levels of corrosion-resistant elements like chromium stainless steel makes it that much harder. Often steel strength and wear resistance are sacrificed for anti-corrosive properties.
It uses a four-digit code to classify carbon and alloy steel and a three-digit code for stainless steel. With carbon and alloys, the first number denotes the main component. For example, 1xxx is carbon steel the most common steel for knives. McHone Industries has a great article explaining this topic in more depth. To make matters more complicated, steel from other countries like Germany and Japan — where many kitchen knives are crafted — has a different grading system.
On top of that, steel companies that paten steel they develop will have another name entirely. Well, we hate to break it to you, but in the end, there are no one or two definitive best types of steel. Forgers, like Brelje, have a favorite kind of steel. Big knife manufacturers prefer certain types. Then you have knife enthusiasts that have tested endless knives yet still have varying opinions.
The best we can do for you is mention some common types of steel used in very well-respected and high-performing knife brands. I feel the reliability comes from working with the same material steel until you figure it out and get consistent results. As we mentioned, knives that are designed for utility or tactical purposes need to use tough, hard, and wear-resistant steel. Here are some of the most commonly used tool steels used in knives.
Kitchen knives are most commonly made from high carbon steel, stainless steel, or a combination of both. The most significant improvement of the AUS series made in Japan over the Series is the addition of vanadium, which improves wear resistance and provides excellent toughness. In general, a thin knife behind the edge and through the spine will cut better than a thick, a s-grind will have better food release and a convex will support an edge better for abuse. Also, lower sharpening angles perform better but must be applied to steels that can support those edges in order to avoid collapsing.
Below you will find information about few popular kitchen knife steels available in the market, in order to know where to look further and what to expect. The list does not cover, by any means, the variety of the kitchen knife steels available. Premium, high wear resistant stainless steels, that take a good edge often referred as super steels.
Its high content of vanadium, molybdenum and chromium contributes to high wear and corrosion resistance as well as edge retention. One of the best options for stainless, wear resistant, kitchen knives. These steels contains high amounts of Carbon, Vanadium and Chromium that form high amounts of carbides wear resistance and contain enough chromium for corrosion resistance. M : Top knife making option but very rare for kitchen knives.
It is produced by third generation powder metal technology that gives very fine grain, high wear resistance with good toughness! It has exceptional corrosion resistance abilities and can be hardened to 62 HRC, moderate difficult to sharpen. ZDP : Non stainless, high chromium carbide super steel from Hitachi. It is considered difficult to sharpen and chips easily in those high hardness values.
Equivalent MC High levels of Molybdenum hence the M in the M4. Excellent edge retention. Gets super hard, holds a good edge for low alloy steel, it is very reactive rust and needs regular maintenance. Same steel as Blue 1 without Chromium and Tungsten.
Achieves great hardness and support excellently thin edges, a little bit tougher than white 1. As you can see, the higher the number of reference, the lower the carbon content, the lower the max hardness but, the higher the toughness! Aogami 1 or Blue 1 Hitachi : Very popular steel in Japanese kitchen knives.
Non stainless and high carbon steel that can achieve high hardness and takes a fine edge all Aogami steels are very pure. Easy to sharpen and good edge retention for a low alloy steel. It can achieve great hardness and take amazing fine edge but it requires the most attention of all also as it is the less tough.
AEB-L : A steel that was originally developed for razor blades. It forms an extremely fine grain, have good edge holding, edge stability, toughness and it is easy to sharpen. A favorite among many knife makers, myself, included. Contains Niobium and Vanadium, which are great carbide formers. Very good edge retention, good toughness for stainless and moderate easy to sharpen. It is a bit tougher and has good corrosion resistance but has reduced edge retention.
S45VN is the newest improvement with better edge retention than S35VN but slightly worse toughness. Better toughness than S30V in higher hardness also. It is preferred because it provides better edge retention in comparison with the other stainless steels.
The Japanese equivalent is ATS BG42 : A very good edge holding stainless steel used in the aerospace industry. It can achieve high Rockwell hardness 62 and it is known for its high strength, good corrosion resistance and fine grain structure. It is moderate hard to sharpen.
D2 : Semi stainless that hardens good, holds a good edge and has good wear resistance. Their element composition is virtually the same. This happens to be to every household somehow and you probably used it at least once in your lifetime.
Sharpens easy. Equivalent: UHB20C. W1 : Famous steel among knifemakers as it is easy to work with and creates fine edge.
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