> knife steels > steel CPM S30V

CPM S30V steel is powder steel. This explains her good performance .The powder fabrication process produces a very homogeneous, high quality steel that is characterized by superior stability, uniformity and stiffness compared to steels from traditional heat production.

Knife steel CPM S30V characteristics

CPM S30V steel is manufactured using the amorphous metal alloy technology (Crucible Particle Metallurgy process), which is what the CPM abbreviation says.

CPM S30V was developed specifically to meet the knife industry's need for quality steel with very high (higher than 440C and steels) strength properties. In terms of wear resistance, S30V steel exceeds 440C by 40%, and 154CM by 30%.

Simply put, CPM S30V is an excellent steel with excellent performance. Doesn't get dull for a long time. Despite the high strength, the blade is quite easy to edit.

Like many high-quality steels in all respects, CPM S30V has a minus, this is the price. Knives made of this steel are quite expensive.

The hardness of CPM S30V knife steel is 59-60 HRC

Analog steel CPM S30V - X220CrV17 6 (Germany)

Steel composition CPM S30V

Carbon (C) - 1.45%,

Manganese (Mn) - 0.40%,

Chromium (Cr) - 14%,

Silicon (Si) - 0.40%,

Molybdenum (Mo) - 2.0%,

Vanadium (V) - 4.0%.

When choosing a pocket knife, you should always pay attention to the type of steel used in the manufacture of the blade. After all, it depends on how good the knife will be in use. Essentially, steel is an alloy of iron, carbon, and alloying additives that improve its performance.

In the production of knives, different steels differ in the type of alloying additions, rolling and heat treatment.

There are five main characteristics of steel:

Hardness. Resistance to deformation when exposed to metal, measured by the Rockwell method.

Rigidity. Resistant to damage such as cracks and chips. The harder the steel, the less rigid it is.

Wear resistance to abrasive and adhesive effects. The harder the steel, the more wear resistant it is, but this characteristic also depends on the chemical composition: a greater amount of tungsten carbide improves wear resistance.

Corrosion resistance. Resistant to rust due to moisture or salt. Greater corrosion resistance negatively affects the characteristics of the edges of the steel.

Protecting the edges from "blockages". That is, how long the blade will remain sharp when using it.

Unfortunately, the best knife steel cannot combine the highest performance of all five characteristics. The best knife steel is achieved through compromise, and the hardest part of that is balancing hardness with toughness. You can make a very hard blade, but if you fall it will break into pieces. Conversely, the blade can be very hard, it will bend well, but it will not retain sharpening for a long time.

CPM-S90V

Manufactured by Crucible. Excellent sharpening and wear resistance, which is achieved due to the high carbon content. The main secret- vanadium, which is 3 times more than that of Elmax and S30V steels. It is very expensive, and its sharpening requires angelic patience, but the knife will remain sharp for an incredibly long time. best example a knife with a blade made of this steel - Benchmade 940-1.

M390

The new steel is produced by Bohler-Uddeholm, which uses third-generation powder metal. The blade made of such steel has excellent corrosion resistance, rigidity and wear resistance. Additives of chromium, molybdenum, vanadium and tungsten ensure a long blade sharpening life. On the Rockwell scale, she has an indicator of 60-62 HRC. A blade made of such steel is difficult to sharpen, but it can be polished to a mirror finish.

ZDP-189

Another novelty is produced by Hitachi. Due to the huge content of carbons and chromium, it is extremely hard. On the Rockwell scale, its figure is 64 HRC, but some manufacturers achieve 66 HRC. Holds an edge well, but the sharpening process itself is extremely time-consuming. This steel is more susceptible to corrosion than competitors.

Elmax

Produced by Bohler-Uddeholm, it is a powder metal alloy with a high content of chromium, vanadium and molybdenum. Extremely resistant to corrosion and wear. Perhaps this is the best knife steel, because its sharpening is relatively easy, and lasts for a long time.

CTS-XHP

Steel from the American company Carpenter holds sharpening well, and its hardness reaches 61 HRC. Also produced from the highest quality metal powder. The sharpening process is quite laborious.

CPM M4

This tool steel from Crucible is manufactured using the patented "Crucible Particle Metallurgy" process, which guarantees a more uniform, stable and easy to grind product than the traditional process. This steel provides an excellent balance of wear resistance and toughness due to its high content of molybdenum, vanadium, tungsten and carbon. It is 62-64 HRC on the Rockwell scale, but due to its low chromium content (less than 14%), it is not considered stainless steel, so it requires proper maintenance.

CPM S35VN

In 2009, Crucible, with the help of Chris Reeve, introduced this steel as an improved version of the S30V. With a smaller grain size and the addition of a small amount of niobium, the company has been able to improve hardness and corrosion resistance and make the steel easier to sharpen. Many believe that the best steel with such characteristics cannot be found.

CPM S30V

This steel holds sharpening well and is almost resistant to corrosion. Used in expensive pocket and table knives. In terms of price / quality ratio, this steel is the best way, with an optimal balance of hardness, stiffness and edge retention.

154CM

The characteristics of this steel are similar to S30V. Its rigidity is sufficient to perform any task, it is almost resistant to corrosion, and keeps sharpening for a long time. The sharpening process itself is quite long, but within reasonable limits. There is also a CPM version of this steel, but ordinary user will not see the difference between them.

ATS-34

Japanese version of 154CM steel with similar characteristics.

D2

This tool steel is also called "semi-stainless" because the amount of chromium contained in it is not enough (you need at least 14%) to be called stainless. But this does not prevent her from having good anti-corrosion properties. It is harder than its competitors, and, accordingly, holds sharpening better. It is less rigid, so it is difficult to sharpen it, and you cannot do without the help of a master.

VG-10

This steel has a slightly higher chromium content than 154CM and ATS-34, and the addition of vanadium makes it a favorite. Made in Japan and widely used in Spyderco knives. It is very very hard, holds an edge well, but is a little brittle.

H1

Spyderco C91SBK Pacific Salt Folding Knife 3-13/16" H1 Satin Serrated Blade, Black FRN Handles

This Japanese steel from Moyodo Metals is a perfect example of a stainless steel that hardly rusts. But there is also a minus: it does not hold sharpening so well, and is very expensive. It is great for diving, but not everyday use.

N680

This steel contains about 0.2% nitrogen and over 17% chromium, making it extremely resistant to corrosion. In fact, this is a cheaper version of the H1, which keeps sharpening longer.

440C

Used in many mainstream pocket knives, it is a good and affordable choice. It is quite rigid and wear-resistant, resistant to corrosion and easily sharpened. The content of chromium and carbon in it is the highest among competitors.

AUS-8

A Japanese version of 440C, it does not hold an edge as well as other high carbon steels.

CTS-BD1

Carpenter's vacuum forged steel is similar in performance to AUS-8 and 8Cr13MoV, but holds an edge better. Due to the higher chromium content, it copes better with corrosion.

8Cr13MoV

This Chinese steel is similar to AUS-8 but contains more carbon. It has an excellent price-performance ratio, and manufacturers like Spyderco, thanks to skillful heat treatment, have been able to achieve High Quality steel.

14C28N

This Swedish steel from Sandvik is an improved version of the 13C26 steel discussed below. It came about when Kershaw asked Sandvik to make 13C26 steel more resistant to corrosion. It has a higher content of chromium and nitrogen and a lower amount of carbon. Possibly the best knife steel in the under $30 category.

420HC

This is a variant of 420 steel, but with a higher carbon content, making it harder. Some manufacturers, like Buck for example, achieve excellent performance with it that outperforms the competition. Despite her low price, it is among the best in anti-corrosion properties.

440A

The same 420HC, but with a high chromium content, which improves wear resistance and sharpening life, but affects corrosion resistance.

13C26

Originally developed for razor blades. It has a higher carbon to chromium ratio, which makes it harder and less resistant to corrosion.

420 and 420J

Despite its low status, it is perfect for everyday use. She has a smaller amount of carbon (less than 0.5%), respectively, she keeps sharpening worse. But this one is so resistant to corrosion, but not to wear. Used in mass products.

AUS-6

Japanese and lower quality steel 420.

“What is the essence of the CPM process?”, you ask. The fact is that the molten metal is poured out through a small hole, where high-pressure gas sprays it into tiny droplets. They are then cooled, solidified to a powder state, and then amenable to the process of hot isostatic pressing. This prevents segregation of alloying elements. The result is a tough, wear-resistant steel that can be ground and heat treated to maximum effect.

But you should not attach such importance to the types of steel. The quality of a knife depends not only on the steel used, but also on the heat treatment technique and on the shape of the blade itself. Any modern steel will work well in any knife. It is better to pay attention to how convenient the knife is in work for you.

1,0 1 -1 20

When choosing a knife, first of all, you should pay attention to the grade of steel from which the blade is made. Steel is the very essence of the blade, and it depends on it how the knife will behave in work. Steel is essentially an alloy of carbon and iron that is often fortified with alloying additions to improve certain characteristics of the material.

In knife production, variations of alloying additives make it possible to obtain different types steels, in addition, the processes of production, rolling and hardening of steels have a great influence on the final result.

Ultimately, to characterize the steels used on the blades of a particular knife, five key properties are distinguished.

Hardness

Hardness is the ability to resist deformation when subjected to pressure and applied forces. Hardness knife steels, usually measured using the Rockwell Scale (HRC).

Strength

Viscosity, the ability to not crack or chip when used under severe conditions. In addition, strength shows the possibility of bending the blade without critical deformations. Chipping and brittleness are the worst enemies of a knife, the consequences of which are sometimes impossible to eliminate. Note that harder steel is likely to be less durable. The measurement of strength is not standardized, unlike hardness.

wear resistance

Wear resistance - the ability of steel to resist abrasive and adhesive wear. Wear resistance is usually directly related to the hardness of the steel, but the chemical composition of the material also plays an important role. In materials of equal hardness, as a rule, steel with larger carbides will resist wear better.

Corrosion resistance

Corrosion resistance is the ability of materials to resist corrosion. Its manifestations, such as rust and pitting, caused by exposure to environment(water, salt, etc.). It should be noted that the generally high anti-corrosion properties of steel have a negative impact on the overall performance of the blade.

Cutting edge retention

This characteristic indicates how long the blade will retain its sharpness with constant use. Edge retention is constantly discussed in knife circles, but does not have a standard way of measuring until now and is more of a subjective assessment. Personally, I consider this property as a combination of wear resistance and resistance to deformation of the PK.

Unfortunately, it is not possible to obtain the "best" steel by increasing all of these properties, usually a compromise. The biggest difficulty is the balance between hardness and strength. The blade can be exceptionally hard, but at the same time will be brittle and brittle when interacting with hard materials. Conversely, a blade can be extremely strong, bend well without breaking, but fail to hold an edge at all. Also, note that "stainless steel" is just a term, and with prolonged exposure to a corrosive environment, almost any steel will corrode. Therefore, considering the intended use of the knife and guided by this article, you will be able to choose the most suitable blade steel option for long and enjoyable use.

Steel types

Tool steel- These are hard alloys, mainly used for the production of cutting tools. This category includes the fairly popular D2, O1 and Crucible's CPM series steels (CPM 3V), as well as the more advanced high speed M4.

Carbon steel A steel typically used in harsh environments where strength and endurance are critical. A common material for the production of survival knives and machetes. These steels hold the cutting edge well and are easy to sharpen, but due to the low chromium content, they are more susceptible to corrosion. The most popular carbon steel for knives is 1095.

Stainless steel is typically carbon steel with chromium added for better corrosion resistance and other additives that increase performance, but usually at the expense of strength. Probably the most popular category of knife steels today, it includes: 400, 154CM, AUS, VG, CTS, MoV, Sandvik and Crucible SxxV powder steels. Please note that stainless steel must contain at least 13% chromium.

Modern steels used to make knives

Below I will give the most popular steel grades in modern knife production. This article should not be taken as the ultimate truth, this is not an exact science, but just my way of classifying various steels based on many different factors.

ULTRA PREMIUM STEEL

CPM-S90V

This steel features extreme wear resistance and edge retention. Along with the expected high carbon content, the main feature of this material is the extraordinary percentage of vanadium, which is almost three times higher than steels such as Elmax or S30V. Of course, it is very expensive and very difficult to handle. machining, but no one can match the abrasive wear resistance and edge retention of the CPM S90V. You can find this steel on a great knife.

M390

It is one of the newest supersteels produced by the Bohler-Uddeholm Corporation (a merger between Bohler of Austria and Uddeholm of Sweden). M390 uses third-generation powder metallurgy, resulting in a knife steel with high corrosion resistance, hardness and wear resistance. Chromium, molybdenum, vanadium and tungsten help improve edge retention. Unlike ZDP-189, most M390 carbides are formed from vanadium and molybdenum, leaving more "free chromium" to fight corrosion. After heat treatment, this steel allows you to get a hardness in the region of 60-62 HRC. A striking example of the use of this material is the latest Saber knife.

ZDP-189

ZDP-189 is another super steel from Hitachi that contains huge amounts of carbon and chromium, resulting in amazing hardness values. On average, it is hardened at 64 HRC, but some knife manufacturers reach values ​​​​of 66 HRC. Naturally, with such hardness, one can expect excellent cutting edge retention, but also very laborious sharpening. You might think that a large number of chromium contributes to corrosion resistance, but it does not. As a result of the interaction of carbon and chromium, there is not much “free chromium” left in the material to resist rust. So this steel, although harder than S30V, is also more prone to corrosion. As you understand, this material is not cheap.

Elmax

Bohler-Uddeholm introduces Elmax as a high chromium, vanadium and molybdenum powdered steel with extremely high wear and corrosion resistance. Elmax is stainless steel but acts like carbon steel in many ways. It holds the cutting edge perfectly, sharpens relatively easily and has good anti-corrosion properties. Is it really the “best in the world” steel? Perhaps. At the very least, Bohler creates huge competition for Crucible powders. An example of using Elmax is a great knife.

CTS-XHP

CTS-XHP is a relatively new American steel (manufactured by Carpenter) that has excellent edge retention and a hardness of around 61 HRC. This is another creation of powder metallurgy where Carpenter engineers have developed an extremely fine grain powder resulting in amazing performance. Edge retention is superior to the S30V, although this steel is a bit more difficult to sharpen. I generally consider CTS-XHP to be a corrosion resistant form of D2 with slightly better edge retention.

PREMIUM STEEL

CPM M4

A high performance tool steel with high toughness and perhaps the best cutting edge retention of any carbon steel. Like all CPM steels, CPM M4 is created using the patented Crucible Particle Metallurgy (CPM) technology, which provides an extremely uniform, stable and easy to machine product compared to traditional steels. CPM M4 has an excellent balance between strength and wear resistance, due to the high percentage of molybdenum (hence the M in the name), vanadium, tungsten, together with a high percentage of carbon. At heat treatment it can reach a hardness of 62-64 HRC. But the main disadvantage of CPM M4 is the low chromium content, so this steel is not stainless and belongs to high carbon steels. The result is the best steel for cutting, but requires constant care to avoid corrosion. Many manufacturers use various coatings that significantly improve oxidation resistance, but note that this is a short-lived solution. Is it easy to sharpen a CPM M4 knife? NO!

CPM S35VN

In 2009, Crucible and Chris Reeve introduced an improved version of their bestselling S30V and called it the CPM S35VN. With a finer grain structure and the addition of niobium (N in the name), they achieve superior strength and ease of sharpening compared to the S30V. To be honest, I can hardly tell the difference between the two steels. There is an opinion that today it is the best supersteel in terms of the combination of its properties: cutting edge retention, strength, corrosion resistance and, of course, cost.

CPM S30V

Crucible's American steel, CPM S30V (often referred to simply as S30V), has excellent edge retention and excellent anti-corrosion properties. This material, developed in the USA, is commonly used on blades of high quality pocket knives and professional kitchen tools. The introduction of vanadium carbides brings extreme hardness to the alloy steel matrix. Considering the cost, this is one of the best knife steels with an optimal balance between edge retention, hardness and toughness. Please note that this steel has an older brother - CPM S35VN, this steel is very similar to S30V, but due to the content of niobium it is easier to process and more convenient for knife manufacturers. However, S30V is quite common these days and is one of the favorite steels for knife makers.

HIGH QUALITY STEELS

154CM

It is a steel of relatively high hardness, which is considered to be an upgraded version of 440C steel by the addition of molybdenum, which retains the same excellent anti-corrosion properties, despite a lower chromium content. 154CM has decent toughness and excellent edge retention. When using the right abrasives, it sharpens quite easily. You can easily find examples of its use from leading knife manufacturers, for example. Also, you can find CPM 154, which is a powdered equivalent made by Crucible. The CPM process produces finer and more uniform carbides resulting in improved steel properties, but I won't claim that the average user will be able to notice this.

ATS-34

This steel can be seen as the Japanese equivalent of the American 154CM. Accordingly, it has very similar properties and characteristics, and is a high-quality steel that has won fame from many knife manufacturers. Compared to 440C, ATS-34 has better edge retention but is less resistant to corrosion.

D2

D2 is a tool steel, often referred to as "semi-stainless" because it contains less chromium than stainless steels, but still resists corrosion quite well. On the other hand, D2 is harder than the 154CM and ATS-34 steels already presented above and as a result has better edge retention. However, it is not as strong as many other steels, and sharpens rather poorly. You need to be patient to sharpen the blade from D2 well.

VG-10

VG-10 is very similar to 154CM and ATS-34, but has a slightly higher percentage of chromium for corrosion resistance. In addition, VG-10 contains vanadium, which increases strength slightly. This steel appeared in Japan and was gradually distributed to the knife market by such companies as etc. This steel has sufficient hardness and can stay sharp for a long time, but it is a bit brittle and prone to chipping. Overall, I really like this time-tested material.

H1

H1 from the Japanese company Myodo Metals has excellent corrosion resistance and virtually no rust. This is the embodiment of true "stainless steel". Naturally, such a property is expensive, and the price is the ability to hold the cutting edge. Therefore, it is great for scuba diving, but I don't think the H1 will suit you on an EDC knife. In addition, it is expensive.

N680

N680 steel contains 0.2% nitrogen and 17% chromium, making it extremely resistant to corrosion. If you plan to use the knife in salt water, then this option is for you. This is a fine steel that is easy to sharpen. Consider it a cheaper alternative to the H1 but with decent edge retention, but don't think it can match the 154CM or ATS-34 in that regard.

QUALITY STEELS

440C

440C is a good general purpose knife steel that has fallen out of favor with the advent of modern super steels. This is a stainless steel widely used on mid-range knives, fully meeting the requirements put forward for knife materials. It has sufficient hardness and wear resistance, but the main difference of this material is its excellent corrosion resistance. It holds a cutting edge much better than the 420HC, but is also easy to sharpen. 440С contains maximum amount chromium and carbon from steels of this subgroup.

AUS-8

This Japanese-made steel strongly resembles 440C in its properties, and even better resists corrosion, but has a slightly lower hardness. It is relatively strong, but will not be able to hold an edge like its older carbon-rich counterparts. Remember, the more carbon, the greater the hardness and the longer the edge retention. AUS-8 will be easy to sharpen to a razor-sharp finish.

CTS-BD1

This is stainless steel, created by order of Spyderco. It is produced by the American company Carpenter and its properties resemble AUS-8 and 8Cr13MoV, but are slightly ahead of them in terms of cutting edge retention. Due to the higher percentage of chromium, it also has better anti-corrosion characteristics. Being a steel with small carbides, it sharpens quite easily, but will not be able to hold an edge as long as, for example, VG-10 (which has large carbides).

8Cr13MoV

This steel is made in China. Its properties can be compared with AUS-8, but 8Cr13MoV has a higher carbon content. This material has an excellent price-performance ratio and many knife manufacturers use this steel. For example, company.

14C28N

Sandvik's 14C28N stainless steel is an improved version of their 13C26 steel, described below. In fact, Kershaw asked for more corrosion resistance on 13C26, resulting in 14C28N. This steel has a little more chromium and a little less carbon, but the real secret is the addition of nitrogen to help fight corrosion. In general, a very worthy material that is relatively easy to sharpen to a razor-like state. You can find examples of the use of 14C28N in the company's products.

MIDDLE RANGE STEELS

440A

440A is very similar to 420CH, but contains more carbon, which makes it harder and keeps the cutting edge longer, but is more prone to corrosion.

420HC

It is considered the best steel in the 420 series, due to the increased carbon content (HC - High Carbon) it has a relatively high hardness. However, it is considered a medium range steel, but manufacturers such as 420HC achieve very good performance through competent heat treatment, which leads to decent cutting edge retention and excellent anti-corrosion properties. By and large, this is one of the best steels in terms of corrosion resistance, despite its low cost.

13C26

Sandvik launches its version of AEB-L, designed for razor blades. 13C26 can be compared to 440A but has slightly more carbon and chromium making it slightly harder and more corrosion resistant. However, in real conditions it is very difficult to distinguish them from each other, since their “behavior” is almost the same. Sandvik later released an improved version of this steel, 14C28N.

1095

It is one of the most popular carbon steels (approximately 1% carbon) and has poor corrosion resistance and good edge retention. Then where does the popularity come from? It's simple, it is a strong steel, resistant to chipping, non-brittle, easily sharpened to razor sharpness and relatively cheap to manufacture. These properties make the 1095 indispensable on large knives with fixed blades for heavy work or on outdoor knives that will be subjected to more severe use than your typical EDC folders. To combat corrosion, manufacturers quite successfully use various coatings and oxidation.

LOW RANGE STEELS

420 and 420J

420 series is at the bottom of the list of knife steels, but can still be used quite successfully in mass production. It has a low carbon content (typically on the order of 0.5%), resulting in low hardness and poor edge retention when compared to higher quality steels. But 420 steel has a decent strength and corrosion resistance, which allows it to be used for the production of kitchen knives and other inexpensive knife products.

AUS-6

It is usually compared to 420 steel. AUS-6 is a relatively soft steel with low carbon content but excellent anti-corrosion properties.

What is the secret of CPM steels?

CPM is an abbreviation for Crucible Particle Metallurgy (Powder Metallurgy Crucible), this technology allows you to get high quality tool steels. American company Crucible is the only manufacturer of CPM steels that are obtained through a complex process. Molten steel under high pressure passed through special fine nozzles, as a result of which the steel is instantly cooled, turning into a fine metal powder. Further, this powder is pressed in special forms and baked. The peculiarity of CPM is that this process allows to obtain fine particles with a uniform composition and allows you to enter the exact amount of alloying additives. The result is a steel with precisely defined properties, increased hardness and wear resistance, which is machined and hardened with maximum efficiency.

What can you say about Damascus steel?

Damascus steel began its history a very long time ago and its roots go to the east, to countries such as India and Pakistan. It is widely known for its characteristic swirling pattern obtained by welding several layers of metal, due to which it is often called "multilayer" (please do not confuse with damask steel, they only have a similar pattern). There are many myths about the magical properties of Damascus steel, but today it is in demand only because of its aesthetic beauty. As a rule, interest in it is shown mainly by collectors.

findings

Remember that knife steel is the main thing, but not everything. Buyers should be careful with their choice of steel so as not to get bogged down in the nuances and differences of the “ideal material”, as this alone is not the only thing that will determine the performance of a knife. The fact that a knife has a blade made of premium steel does not make it better than a knife with a blade made of a simpler material. The heat treatment methods used by the manufacturer, as well as the design of the product itself, play a huge role in obtaining a quality end product.

In fact, all modern steels fully satisfy the average needs of most users. Therefore, I suggest paying enough attention to other aspects of the knife, such as form factor, handle, ergonomics, etc.

Analogues of Russian and foreign steels

The countries and their metal standards are listed below:

• Australia - AS (Australian Standard)
• Austria - ONORM
• Belgium - NBN
• Bulgaria - BDS
• Hungary-MSZ
• United Kingdom - B.S. (British standard)
• Germany - DIN (Deutsche Normen), WN
• European Union - EN (European Standard)
• Italy - UNI (Italian National Standards)
• Spain - UNE (Espaniol National Standards)
• Canada-CSA (Canadian Standards Association)
• China - GB
• Norway-NS (Standards Norway)
• Poland-PN (Poland Standard)
• Romania - STAS
• Russia - GOST (State standard) , THAT (Specifications)
• USA - AISI (American Iron and Steel Institute), ACI (American Concrete Institute), ANSI (American National Standards Institute), AMS (American Mathematical Society: Mathematics Research and Scholarship) API (American Petroleum Institute), ASME (American Society of Mechanical Engineers), ASTM (American Society of Testing and Materials), AWS (American Welding Society), SAE (Society of Automotive Engineers), UNS
• Finland-SFS (Finnish Standards Association)
• France - AFNOR NF (association francaise de normalization)
• Czech Republic - CSN (Czech State Norm)
• Sweden-SS (Swedish standard)
• Switzerland-SNV (Schweizerische Normen-Vereinigung)
• Yugoslavia - JUS
• Japan - JIS (Japanese Industrial Standard)
• International Standard - ISO (International Organization for Standardization)

In the United States, several systems are used to designate metals and alloys associated with existing organizations for standardization. The most famous organizations are:

• AISI - American Iron and Steel Institute
• ACI - American Institute of Casting
• ANSI - American National Institute Standardization
• AMS - Aerospace Materials Specification
• ASME - American Society of Mechanical Engineers
• ASTM - American Society for Testing and Materials
• AWS - American Welding Society
• SAE - Society of Engineers - Motorists

Below are the most popular steel designations used in the US.

AISI notation system:

Carbon and alloy steels:
In the AISI designation system, carbon and alloy steels are usually designated with four digits. The first two digits indicate the number of the steel group, and the last two indicate the average carbon content in steel multiplied by 100. So steel 1045 belongs to the group 10XX high-quality structural steels (non-sulfinated with Mn content less than 1%) and contains about 0.45% carbon.
Steel 4032 is doped (group 40XX), with an average content of C - 0.32% and Mo - 0.2 or 0.25% (the actual content of C in steel 4032 - 0.30 - 0.35%, Mo - 0.2 - 0.3%).
Steel 8625 is also doped (group 86XX) with an average content: C - 0.25% (real values ​​0.23 - 0.28%), Ni - 0.55% (0.40 - 0.70%), Cr - 0.50% (0.4 - 0.6%), Mo - 0.20% (0.15 - 0.25%) .
In addition to four digits, letters can also be found in the names of steels. At the same time, the letters B and L, meaning that the steel is alloyed with boron (0.0005 - 0.03%) or lead (0.15 - 0.35%), respectively, are placed between the second and third digits of its designation, for example: 51B60 or 15L48.
Letters M and E put in front of the name of the steel, this means that the steel is intended for the production of non-responsible long products (letter M) or smelted in an electric furnace (letter E). A letter may be present at the end of the steel name H, meaning that a characteristic feature of this steel is hardenability.

Stainless steels:
AISI designations for standard stainless steels include three digits followed in some cases by one, two or more letters. The first digit of the designation determines the steel class. So the designations of austenitic stainless steels begin with numbers 2XX and 3XX, while ferritic and martensitic steels are defined in the class 4XX. At the same time, the last two digits, unlike carbon and alloy steels, are in no way connected with chemical composition, but simply determine the serial number of steel in the group.

Designations in carbon steels:
10XX - Unrefined steels, Mn: less than 1%
11XX - Resulphinated steels
12XX - Rephosphorized and resulphinated steels
15XX - Unrefined steels, Mn: more than 1%

Designations in alloy steels:
13XX - Mn: 1.75%
40XX - Mo: 0.2, 0.25% or Mo: 0.25% and S: 0.042%
41XX - Cr: 0.5, 0.8 or 0.95% and Mo: 0.12, 0.20 or 0.30%
43XX - Ni: 1.83%, Cr: 0.50 - 0.80%, Mo: 0.25%
46XX - Ni: 0.85 or 1.83% and Mo: 0.2 or 0.25%
47XX - Ni: 1.05%, Cr: 0.45% and Mo: 0.2 or 0.35%
48XX - Ni: 3.5% and Mo: 0.25%
51XX - Cr: 0.8, 0.88, 0.93, 0.95 or 1.0%
51XXX - Cr: 1.03%
52XXX - Cr: 1.45%
61XX - Cr: 0.6 or 0.95% and V: 0.13% min or 0.15% min
86XX - Ni: 0.55%, Cr: 0.50% and Mo: 0.20%
87XX - Ni: 0.55%, Cr: 0.50% and Mo: 0.25%
88XX - Ni: 0.55%, Cr: 0.50% and Mo: 0.35%
92XX - Si: 2.0% or Si: 1.40% and Cr: 0.70%
50BXX - Cr: 0.28 or 0.50%
51BXX - Cr: 0.80%
81BXX - Ni: 0.30%, Cr: 0.45% and Mo: 0.12%
94BXX - Ni: 0.45%, Cr: 0.40% and Mo: 0.12%

Additional letters and numbers following the numbers used to designate AISI stainless steels mean:
xxxL - Low carbon content< 0.03%
xxxS - Normal carbon content< 0.08%
xxxN - Added nitrogen
xxxLN - Low Carbon< 0.03% + добавлен азот
xxxF - Increased content of sulfur and phosphorus
xxxSe - Added selenium
xxxB - Added silicon
xxxH - Extended range of carbon content
xxxCu - Added copper

Examples:
Steel 304 belongs to the austenitic class, the carbon content in it< 0.08%. В то же время в стали 304 L total carbon< 0.03%, а в стали 304H carbon is determined by the interval 0.04 - 0.10%. The specified steel, in addition, can be alloyed with nitrogen (then its name will be 304 N) or copper ( 304 Cu).
in steel 410 , belonging to the martensite - ferritic class, the carbon content<< 0.15%, а в стали 410S- carbon< 0.08%. В стали 430F unlike steel 430 high content of sulfur and phosphorus, and in steel 430 FSe added selenium.

ASTM notation:

The designation of steels in the ASTM system includes:

• letter A, meaning that we are talking about black metal;
• serial number of the normative document ASTM (standard);
• the actual designation of the steel grade.

Typically, ASTM standards use the American notation for physical quantities. In the same case, if the metric notation is given in the standard, a letter is placed after its number M. ASTM standards, as a rule, determine not only the chemical composition of steel, but also a complete list of requirements for steel products. To designate the steel grades themselves and determine their chemical composition, both ASTM's own designation system can be used (in this case, the chemical composition of steels and their marking are determined directly in the standard), as well as other designation systems, for example AISI - for bars, wire, billets and etc., or ACI - for stainless steel castings.

Examples:
A 516 / A 516M - 90 Grade 70 Here A defines that it is black metal; 516 is the serial number of the ASTM standard ( 516M- this is the same standard, but in the metric notation); 90 - year of publication of the standard; Grade 70- steel grade. In this case, ASTM's own steel designation system is used, here 70 defines the minimum tensile strength of steel in tensile tests (in ksi, which is about 485 MPa).
A 276 Type 304 L. This standard uses the designation of the steel grade in the AISI system - 304 L.
A 351 Grade CF8M. The ACI notation is used here: first letter C means that the steel belongs to the group of corrosion-resistant, 8 - determines the average content of carbon in it (0.08%), M- means that molybdenum is added to the steel.
A 335 / A 335M grade P22; A 213 / A 213M grade T22; A 336 / A 336M class F22. These examples use ASTM's own steel markings. The first letters mean that the steel is intended for the production of pipes ( P or T) or forgings ( F).
A 269 grade TP304. A combined notation is used here. Letters TP determine that the steel is intended for the production of pipes, 304 - this is the designation of steel in the AISI system.

Universal notation UNS:

UNS is a universal designation system for metals and alloys. It was created in 1975 to unify the various notation systems used in the United States. According to UNS, steel designations consist of a letter that defines the steel group and five digits.
In the UNS system, it is easiest to classify AISI steels. For structural and alloy steels included in the group G, the first four digits of the name are the steel designation in the AISI system, the last digit replaces the letters that occur in the AISI designations. So letters B and L, meaning that the steel is alloyed with boron or lead, correspond to the numbers 1 and 4 , but the letter E, meaning that the steel was smelted in an electric furnace, - a figure 6 .
The names of AISI stainless steels begin with the letter S and include the AISI designation of the steel (the first three digits) and two additional digits corresponding to the additional letters in the AISI designation.

Designations of steels in the UNS system:
Dxxxxx - Steels with prescribed mechanical properties
Gxxxxx - AISI carbon and alloy steels (excluding tool steels)
Hxxxxx - Same, but for hardenable steels
Jxxxxx - Cast steels
Kxxxxx - Steels not included in the AISI system
Sxxxxx - Heat and corrosion resistant stainless steels
Txxxxx - Tool steels
Wxxxxx - Welding consumables

Additional letters and numbers following the numbers used to designate UNS stainless steels mean:
xxx01 - Low carbon content< 0.03%
xxx08 - Normal carbon content< 0.08%
xxx09 - Extended range of carbon content
xxx15 - Added silicon
xxx20 - Increased content of sulfur and phosphorus
хxx23 - Added selenium
xxx30 - Added copper
xxx51 - Added nitrogen
xxx53 - Low carbon content< 0.03% + добавлен азот

Examples:
Carbon steel 1045 has a designation in the system UNS G 10450, and alloy steel 4032 - G40320.
Steel 51B60, doped with boron, is called in the system UNS G51601, and steel 15L48, doped with lead, - G 15484.
Stainless steels are designated: 304 - S30400, 304 L - S30401, 304H - S30409, a 304 Cu - S30430.

steel grade			Analogues in US standards
CIS countries GOST	Euronorms
R0 M2 SF10-MP
R2 M10 K8-MP
R6 M5 K5-MP
R6 M5 F3-MP
R6 M5 F4-MP
R6 M5 F3 K8-MP
R10 M4 F3 K10-MP
R6 M5 F3 K9-MP
R12 M6 F5-MP
R12 F4 K5-MP
R12 F5 K5-MP

Structural steel:

steel grade			Analogues in US standards
CIS countries GOST	Euronorms

Basic range of stainless steel grades:

CIS (GOST)	Euronorms (EN)	Germany (DIN)	USA (AISI)
03 X17 H13 M2		X2 CrNiMo 17-12-2
03 X17 H14 M3		X2 CrNiMo 18-4-3
03 X18 H10 T-U
06 HN28 MDT		X3 NiCrCuMoTi 27-23
08 X17 H13 M2		X5CrNiMo 17-13-3
08 X17 H13 M2 T		Х6 CrNiMoTi 17-12-2
		Х6 CrNiTi 18-10
20 Х25 Н20 С2		X56 CrNiSi 25-20
03 X19 H13 M3
02 X18 M2 BT
02 X28 N30 MDB		X1 NiCrMoCu 31-27-4
03 X17 H13 AM3		X2 CrNiMoN 17-13-3
03 X22 H5 AM2		X2 CrNiMoN 22-5-3
03 X24 H13 G2 S
08 X16 H13 M2 B		X1 CrNiMoNb 17-12-2
08 X18 H14 M2 B	1.4583 X10 CrNiMoNb	X10 CrNiMoNb 18-12
		X8 CrNiAlTi 20-20
		X3 CrnImOn 27-5-2
		Х6 CrNiMoNb 17-12-2
		Х12 CrMnNiN 18-9-5

Bearing steel:

steel grade			Analogues in US standards
CIS countries GOST	Euronorms

Spring steel:

steel grade			Analogues in US standards
CIS countries GOST	Euronorms

Heat resistant steel:

steel grade			Analogues in US standards
CIS countries GOST	Euronorms

Compliance between domestic and foreign steel and pipe standards

Steel standards

Germany		European Union	ISO standard	England	France	Italy	Russia
DIN 17200 SEW 550 SEW 555	heat-treated steel				NFA 35-552 EN 10083	UNI 7845 UNI 7874	GOST 4543-71
	case hardened steel						GOST 4543-71
	hot rolled steel for annealed springs
	spring wire and steel tape of rustless steel
	ball bearing /trolley steel
	temperature and high temperature material grade for screws and nuts						GOST 5632-72
	forging and rolled or forged steel bar of temperature, weldable steel		ISO 2604/1 ISO/TR 4956
	tool steel including high-speed steel						GOST 1435 GOST 19265 GOST 5950
DIN 17440 SEW 400				BS 970/1 BS 1554-81 BS 1502-82 BS 1503-89		UNI 6900 UNI 6901	GOST 5632-72
	rustless steel for medical equipment
	rustless steel for surgical implant
	valve material grade						GOST 5632-72
	non magnetic steel
SEW 470 DIN 17145	heat resistant steel			BS 1554-81 BS 970/1		UNI 6900 UNI 6901	GOST 5632-72
	construction steel

Steel CPM® 3V ™ - high-strength wear-resistant tool powder steel from the American metallurgical company "Crucible Industries" (USA). In terms of impact strength, CPM 3V surpasses such steels as, Cru-Wear, CPM M4 and perfectly holds power and cutting loads. This means that it is possible to give a knife made of CPM 3V a greater load with the same thickness of the slopes and makes it possible to make the reduction even thinner, which means that it will be easier to cut with such a knife.

Powder steel CPM 3V is intended for use in the production of blades in the hardness range of 58-60 HRc with a high probability of chipping or breakage during operation. CPM 3V is one of the most mechanically strong and tough steels. Excellent balance of hardness, wear resistance and strength.

Not being stainless, CPM 3V still has a sufficiently high corrosion resistance, so knives made from it, although they require maintenance, are not afraid of being used in corrosive environments.

Quite popular on custom knives, often the potential of this steel is unrevealed due to processing for low hardness (typically 58 HRc, sometimes even 56 ..). When processed to a hardness of 62-63 HRc, the steel has a cutting edge life of about 50% of CPM 10V, at 58 HRc - several times less ...

The steel is made using the technology of amorphous metal alloys, better known among knife makers and hobbyists under the acronym CPM (Crucible Particle Metallurgy). The CPM process makes it possible to produce a very uniform, high quality steel that is characterized by superior stability, uniformity and toughness compared to steels from traditional heat production.

Powdered high speed steel was developed in Sweden in the late 60s of the last century. The powder metallurgy method makes it possible to introduce more alloying elements into the steel without reducing the strength and machinability.

Powder steel, unlike ordinary steel, is fed in molten form through a special nozzle through a stream of liquid nitrogen. Steel quickly hardens into small particles. The result is a powder with a uniform arrangement of carbides (the place of accumulation of carbides is the place where cracks originate). Carbides perform the same function in the composition of steel as cobblestones on the street: they (carbides) are harder than the steel surrounding them, and contribute to its increase in wear resistance.

The resulting powder is sieved and placed in a steel container in which a vacuum is created. Next, the contents of the container are sintered at high temperature and pressure - thus achieving material homogeneity. This process is called hot isostatic pressing. The steel is then pressure treated. The result is a high speed steel with very small carbide particles evenly distributed in the steel substrate. The resulting steel can be rolled in the traditional way, as well as serial grades of steel, resulting in its increased strength.

Differences in the wear resistance of different grades of powder steel are explained by the presence of different carbides in their composition in different proportions and with different distribution uniformity throughout the steel volume. Of two steels having approximately the same hardness, the more wear-resistant will be the one in which there are more carbides or they are harder.

Steel composition:

C 0.83%- the carbon content in the alloy is 0.83%. Carbon is the most important element in steel, it increases its strength and gives the metal good hardness.

Cr 7.49%- the content of chromium in the alloy is 7.49%. Chromium is a greyish-white lustrous hard metal. Chromium affects the ability of steel to harden, gives the alloy anti-corrosion properties and increases its wear resistance. Contained in stainless steel of any brand.

Mo 1.3%- the content of molybdenum in the alloy is 1.3%. Molybdenum is a silvery white metal. Molybdenum is a hard-melting element, it prevents the blade from brittleness and fragility, giving it the necessary rigidity, making it sufficiently resistant to high temperatures.