Knife making: what steel is best

What criteria must the steel meet? 

Different types of steel have different properties. Material for the production of knives is evaluated according to the following criteria: 

  * Resistant to a wide range of temperatures (-30…+100°C). 

  * Susceptibility to corrosion. 

  * Strength, elasticity. Minimal metal deformation and resistance to longitudinal bending are important during the operation of the product. 

  * Hardness. The indicator is abbreviated HRC (in Europe - RC), it is evaluated according to the Rockwell scale. The index of knives exceeding 55 units is considered optimal. As hardness increases, resistance decreases. 

  * Need for sharpening. The harder the material, the less often the blade snaps. 

Steel composition and additives 

  Steel is an alloy of iron and carbon. Blades made of unalloyed steel (without additives) are flexible, but susceptible to corrosion and damage. In order to improve the properties of the metal, impurities are added to the alloy.

  Sulfur and phosphorus are technological impurities. Sulfur reduces the hardness and strength of the metal, in high-quality alloys the percentage does not exceed 0.065. Phosphorus increases the brittleness of steel. This element is present in all alloys, but the maximum amount of material in an alloy can be 0.045%. 

The best types of steel by country 

  Different types of steel have different performance characteristics, and all types have advantages and disadvantages. 

D2 steel 

  It is a type of high-quality German tool steel that has a uniform structure after hardening. One of the most demanded steels in the world. Advantages: 

  * little need for sharpening; 

  * high cutting quality; 

  * resistance to corrosion and deformation. 

  D2 steel is a high carbon steel. It is often used to make teeth for cutting techniques, and is also used in the production of hunting knives. Contains a lot of chromium (up to 14%). Hardened (55-69 HRC). It's reasonably hard for its low price, but it's hard to sharpen. To extend the life of the blade, it is recommended to clean it thoroughly after each use. 

CPM S35VN steel 

  The brand of the American company belongs to the premium class, is characterized by hardness, wear resistance. The abbreviation CPM is the technology name of Crucible Particle Metallurgy. The alloy is obtained by the powder method, which consists of the following steps: 

  a) The liquid alloy is cooled with nitrogen, then it crystallizes and turns into a powder.
  b) The dry material is exposed to high temperature and pressure, thus sintering the powder.
  c) The alloy is pressed until the final product is obtained. 

  Grade S35VN is an improved version of S30V (niobium is added to the alloy and fine powder is used in production). The combination of alloyed elements made it possible to improve the properties of steel without losing strength: 

  * Due to the structure of the fine-grained material, the product retains its sharpness for a long time and is less crushed compared to the previous brand. 

  * The blade is impact resistant.

  * Steel is less susceptible to decay. 

  * The alloy is characterized by plasticity. 

  The disadvantages of the brand are: the difficulty of sharpening and the high price. Such knives are not intended for cutting hard surfaces, they are not resistant to bending (blade hardness is from 58 to 62 units according to the Rockwell scale). 

440C steel 

  Considered a classic knife steel in Europe and America, it has increased chromium and carbon content. Knives made of 440C steel do not rust. Main features: 

  * hardness 59 HRC; 

  * withstands bending, rotation (can be used when cutting solid dense products); 

  * belongs to the stainless steel category (suitable for use by divers and fishermen); 

  * requires more frequent sharpening; 

  Classic and folding knife models are often made of 440C steel. Products require regular maintenance. Due to the absence of vanadium in the alloy, the blades have no wear resistance. Compared to premium products, they are sensitive to salts and acids. 

ELMAX steel 

  Steel of the Swedish brand is produced using powder technology. It is a high carbon alloy. It is used for the production of knives in the high price category. It has good cutting properties. Advantages: 

  * hardened 58-62 (according to the Rockwell scale); 

  * impact resistant; 

  * abrasion resistant; 

  * corrosion resistant. 

  High hardness steel lends itself well to sharpening. Regular grinding and polishing of the blade is necessary to maintain its anti-corrosion properties. 

M390 steel 

  The M390 brand, developed by an Austrian metallurgical concern, is one of the best. It is resistant to breakage. It was developed as a material for making medical instruments. The main advantage is the hardness of 60 to 62 HRC. With this indicator, the surface of the knife can be polished to a mirror level. A desktop machine is required for sharpening. 

ZDP189 steel 

  The ZDP189 brand belongs to a Japanese corporation. This high-carbon tool steel, with a hardness of up to 69 HRC, is high in chromium. Created on the basis of powder technology. It stands out for its cutting properties and is used for the production of limited series knives. Due to its fragility, it is not suitable for all shapes of knives (for example, it is not recommended for concave models). Metal is impact sensitive. 

VG-10 steel 

  Alloyed with cobalt and molybdenum, Japanese grade VG-10 excels in cutting edge sharpness, hardness, impact resistance and anti-corrosion properties. The cobalt alloy in the composition makes the steel harder. The cutting edge remains sharp for a long time even with a hardness of 60-62 HRC. The quality of the steel is maintained by a special heat treatment method, which the manufacturer keeps secret. 

CPM S30V steel 

  The American brand CPM S30V steel has from 13 to 18% chromium, is characterized by strength and rust resistance. The alloy contains carbides of vanadium and chromium. The material combines impact resistance and abrasion resistance, and is resistant to breakage. The hardness of the blade is up to 58-61 HRC. 

AUS-8 steel 

  Made in Japan, AUS-8 steel has high performance. Due to the presence of molybdenum and nickel in the alloy, corrosion resistance is ensured. The melting and tempering process does not use expensive technologies, so the metal has a low price. Knives made of this material do not require special maintenance, combine hardness and elasticity, and are easy to sharpen. 

The best types of household steel 

  The designation of two numbers and the letter "X" indicates the percentage (in hundredths) of carbon and chromium (the first number is carbon, the second is chromium). Actual numbers may vary slightly. The 5 best steels for making knives can be distinguished: 

50x14MF steel 

  Universal steel 50x14MF, with which the production of weapons began. It is used in the production of knives, medical instruments. The alloy is resistant to chemical and humid environments. The hardness can be up to 57-58 HRC. 

40x12 steel 

  It is a soft highly alloyed steel used in the production of inexpensive knives and souvenir knives. It is difficult to harden, so the blade bends easily and the cutting edge hardly retains its sharpness. The advantage is corrosion resistance. The hardness of the material is 51 or 52 HRC. 

H12MF steel 

  It was originally developed for use in the engineering industry. The brand is widely used in the production of knives. The alloy includes secondary raw materials, which reduces the cost of production. Disadvantages include sensitivity to bending and acidic environments, the need for special sharpening equipment, and the dull appearance of the blade. 

95x18 steel 

  Often used to make knives. The material is resistant to corrosion, durable, does not wear out for a long time. The advantage is the ease of sharpening the blade, the disadvantage is the average cutting sharpness. Hardness up to 58 HRC. 

65x13 steel 

  Refers to inexpensive brands. Rust resistant due to chromium content. The hardness ranges from 56 to 59 HRC. Steel is resistant to impacts and deformations. The maintenance of the knife is also simple, it is easy to sharpen. The disadvantage is that it wears out quickly. 

What steel to choose 

  When choosing a kitchen knife or hunting knife, the quality of the material and the reputation of the manufacturer are taken into account. 

Steel for kitchen knives 

  A knife to be used in the kitchen must be durable. An important parameter is the cutting quality. The blade should be easy to sharpen, but not require frequent sharpening. The best kitchen knives meet the following parameters: 

  * resistant to rust; 

  * does not crumble with frequent use;

  * no irregularities in the cutting edge. 

  In Russia, the steel most commonly used for kitchen knives is labeled:

65X13;

40X12;

95X18; 

50x14MF. 

  Among the brands of other countries, 440C steel has a high rating. For kitchen knives, Japanese steel AUS10 and ATS34 are recommended, as well as American 154 CM. Steel 420 is also often used, but preference should be given to manufacturers from the USA, Switzerland, Austria, Germany. Spanish knives made of 420 steel are soft. In European versions, massive knives are often found, with which it is difficult to cut products accurately. 

Steel for hunting knives 

  Fishing and hunting knives must be made of durable material. Commonly used types: 

  420 (inexpensive models); 

  440A, B, C; 

  JAV 4-10;

  Elmax;

  95X18; 

  H1 (American chrome nickel steel). 

  The knife must stand out for its cutting properties, remain sharp for a long time, be strong and not crumble. Alloys with a hardness lower than 55 and higher than 60 HRC are not suitable for a hunting knife. Steel with a higher hardness index can break quickly. 

Is Damascus steel really that good? 

  High-quality Damascus steel surpasses many types of steel in its cutting properties. Damascus alloy has a hardness of 60 HRC, is durable and has a very sharp edge. Another advantage is good retention of cutting properties. Products are often decorated with patterns, which are formed due to the heterogeneous structure. But Damascus steel also has disadvantages - it is not completely resistant to corrosion and requires careful maintenance.