How To Choose The Best Steel For Knives

In the production of a custom knife, great attention must be given to the selection of steel used for the blade. Blade steel, along with edge geometry and design, is a critical factor that determines the performance of the knife. 

The quality of the steel used in manufacturing a knife is dependent on the alloy used, which is typically a combination of carbon and iron with other elements added for specific applications. 

Additionally, the varying types of additive elements and techniques of rolling and heating the blade can result in different types of steel. When selecting a type of steel for a knife blade, several key properties must be considered. 

So In this post we’re going to tell you about the best steels for knife manufacturing and how they can impact performance.

Factors to consider when choosing knife steel for manufacturing

When choosing knife steel for manufacturing, several factors must be considered to ensure that, the knife meets the intended use and performs well. Here are some of the critical factors to consider:

Hardness: Hardness implies blade’s ability to resist deformation when subject to stress or any forces applied.  Hardness of knife steels  is immediately connected with strength and is normally measured using the  Rockwell hardness scale.  The hardness of the steel affects how well the blade retains its edge. Harder steel tends to hold an edge longer but can be more challenging to sharpen. On the other hand, softer steel is easier to sharpen but may require more frequent sharpening. At the same time, hard steel blades can be brittle and tend to chip or even shatter under impact.

Toughness: Toughness is blade’s endurance against cracks or chips when subject to abrupt stress or impact. Tougher steel can withstand heavy use without chipping or breaking. Mind that chipping is a major hazard for any knife. This factor is especially important for knives used in outdoor or survival situations.

Corrosion resistance: Depending on the intended use and environment, the blade may be exposed to moisture and harmful elements that can cause rust and corrosion. Corrosion resistance represents metal’s aptitude to stand against corrosion or rust caused by factors like moisture or salt. Corrosion resistance is due to the fact that chromium forms a “passive film” of chromium oxide, which prevents further corrosion. Without the passive film, rust forms which tends to flake off and the steel continues to corrode. More chromium means that the passive film on the steel surface is more complete and better prevents corrosion. There is no fixed limit at which a certain amount of chromium is enough to prevent corrosion, it depends on the environment. Stainless steel is often chosen for its resistance to corrosion. However, not all stainless steel is created equal, and some grades of stainless steel are more corrosion-resistant than others.

Wear resistance: Wear resistance implies that the steel is able to survive impact from wear of various types. It might be abrasive wear when harder particles impact a softer surface, or adhesive wear when wear debris or grit migrate to a foreign surface. Although wear resistance mainly depends on steel’s hardness, the particular chemistry of the steel is also a substantial factor. Steel with high wear resistance tends to last longer and require less frequent sharpening. However, higher wear resistance can also lead to decreased toughness, so it’s important to strike a balance between wear resistance and toughness.

Edge retention: Edge retention indicates how long the blade remains sharp enough to perform intended operations. There is no prescribed set of standards to measure edge retention and user’s evaluations of it will often be subjective.  When comparing steels with constant hardness, edge retention depends on the amount and type of carbide in the steel. More carbide and harder carbide provide better edge retention. You should keep in mind that, in endeavoring to have the best of your blade, you will always have to face a trade-off. Balancing knife’s strength with toughness, or toughness with edge resilience, can be a challenging task. Making a blade extremely hard may pose a risk of its losing toughness and chipping at sudden impact. On the contrary, making your blade very tough may result in its struggling to hold edge well. It’s all about your intended knife use: how exactly you’re going to use your knife shall define an optimal combination of various factors in the blade steel.

Edge geometry: When it comes to edge retention, edge geometry is another factor to consider because the type of steel chosen will indirectly impact the sharpening angle and choosing an incorrect sharpening angle will lead to a decrease in the life expectancy of your knife.

Cost: The cost of the steel can vary significantly, and more expensive steel does not necessarily mean better performance. The intended use of the knife should be weighed against the cost of the steel to determine the best value. For example, a high-end chef’s knife may require a more expensive steel to achieve the desired performance, while a utility knife used for everyday tasks may not require such an expensive steel.

Manufacturing constraints: The manufacturing process can also affect the choice of steel. Some steels may be more difficult to work with or require specialized equipment, which can increase manufacturing costs. The intended manufacturing process should be considered when selecting the steel.

Common Knife Steel Types and Their Characteristics

There are many types of steel used for making knife blades, each with its own characteristics and properties. Here are some of the most common types of knife steel and their characteristics:

Carbon Steel: Carbon steel is a popular choice for knife blades because it is relatively easy to sharpen and holds a sharp edge well. It is also tough and durable. However, it is prone to rust and requires more maintenance than stainless steel.

Stainless Steel: Stainless steel is an alloy of iron, carbon, and other elements that resist corrosion. It is easy to maintain and requires little upkeep, making it a popular choice for kitchen knives. However, stainless steel may not hold an edge as well as high-carbon steel.

Damascus Steel:  Damascus steel  is a type of steel that is made by layering and forging multiple types of steel together. It has a distinctive pattern and is known for its strength, durability, and ability to hold a sharp edge.

High-Carbon Steel: High-carbon steel similar to carbon steel but the difference is that it  contains a high percentage of carbon, which makes it tough, durable, and able to hold a sharp edge well. However, just like regular steel, it is also more prone to rust and requires more maintenance than stainless steel.

Tool Steel: Tool steel is a type of steel that is designed for use in cutting and shaping tools, including knives. It is extremely tough and durable and can hold an edge well. However, it can be more difficult to sharpen than other types of steel.

Powder-metallurgical steel: Particle steel steel is a type of steel that is made by mixing different types of steel powders together and then sintering them. It has a fine, even grain structure that makes it strong, durable, and able to hold an edge well.

VG-10: VG-10 is a high-quality Japanese steel that is known for its toughness, durability, and ability to hold an edge well. It is often used in high-end chef knives and other high-performance knives such as hunting knives, carving knives and pocket knives.

These are just a few examples of the many types of knife steel available. When choosing the best steel for a knife, it is important to consider the intended use of the knife and the properties of the steel.

Low-End Steel Types

420J steel

CORROSION RESISTANCE: 8 EDGE RETENTION: 2  EASE OF SHARPENING: 9

A low-end steel that is still fine for many general use applications. A low carbon content (below 0.5%) results in a softer blade and poorer edge retention. However, it is generally tough, highly stain resistant but poorly resistant to wear and tear. This steel is typically used in budget mass-produced knives.

K.I.S.S. Folding Pocket Knife with Frame Lock 5500. Knife blade is 420J stainless steel.

AUS-6 steel

CORROSION RESISTANCE: 5 EDGE RETENTION: 3  EASE OF SHARPENING: 9

The Japanese counterpart to the 420 series steel. This low-quality soft steel has low carbon content but features a fair corrosion resistance index.

Hattori SAN-GECKO Limited Edition GECKO-11 Blue Bowie Hunter. AUS-6 Molybdenum/Vanadium stainless steel blade.

Low-Mid Range Steel Types

440A steel

CORROSION RESISTANCE: 5 EDGE RETENTION: 3  EASE OF SHARPENING: 9

Very similar to 420HC but with a bit more carbon which provides increased wear resistance and better edge retention but poorer anti-rust qualities.

Boker Magnum Eternal Classic. The knife blade made of satin-finished 440A steel.

420HC steel

CORROSION RESISTANCE: 8 EDGE RETENTION: 3  EASE OF SHARPENING: 9

Generally deemed as the ultimate of the 420 steels, 420HC is similar to 420 steel. An increased rate of carbon makes 420HC harder than 420 steel. If properly heat treated it can be honed to fine edge retention and corrosion resistance. A lower-mid range steel that has become quite popular due to its affordability and superb corrosion resistance for the price.

Leatherman FREE T2 Multi-Tool Pocket Knife. Blade Material: 420HC Steel.

13C26 steel

CORROSION RESISTANCE: 4 EDGE RETENTION: 3  EASE OF SHARPENING: 7

A version of the AEB-L steel originally developed for razor blades. Comparable to 440A steel, however a higher carbon-to-chromium ratio makes it a bit harder at the cost of rust resistance. In real world uses the two steels tend to perform quite similarly. 

Buck Bond Arms Liner Lock Folding Knife. The blade of the knife is made of Sandvik 13C26 steel.

1095 steel

CORROSION RESISTANCE: 2 EDGE RETENTION: 3  EASE OF SHARPENING: 8

This standard carbon steel (about 1% carbon) has low corrosion resistance and average edge retention. However it features high toughness – that is, this steel withstands chipping, is easy to hone to a very sharp edge. Also, this steel is moderately priced in terms of production. 1095 is popular in heavy duty and hunting knives facing more roughness than a typical EDC knife. 

TOPS Knives Steel Eagle 107E Fixed. 1095 Carbon steel Blade.

Mid-Upper Range Steel Types

440C steel

CORROSION RESISTANCE: 4 EDGE RETENTION: 4  EASE OF SHARPENING: 6

A decent all-round stainless steel commonly used in many mass-produced pocket knives. Fairly tough and wear resistant, this steel features excellent stain resistance. Has fair edge retention and corrosion resistance, while can be sharpened pretty easily. 

Bohler N695 steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 5  EASE OF SHARPENING: 6

An improved version of 440C, this stainless steel is used in many survival knives. A softer steel as compared to most other available higher-end steels, it is similar to VG-10.

The popular Boker Arbolito Hunter knife. The blade made of Bohler N695 stainless steel.

AUS-8 steel

CORROSION RESISTANCE: 4 EDGE RETENTION: 3  EASE OF SHARPENING: 8

The Japanese alloy is slightly more resistant to corrosion than 440C but less hard. Has similar toughness but poorer edge retention, while being easy to sharpen to a razor edge.

Cold Steel OSS Double-Edged Fighter fixed blade knife. Japanese AUS 8A stainless steel blade.

CTS-BD1 steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 4  EASE OF SHARPENING: 6

A vacuum-melted stainless steel comparable to AUS-8 and 8Cr13MoV. A relish of chromium imparts better corrosion resistance. Is easy at sharpening but has poorer wear resistance than similar high carbide steels.

Spyderco Polestar Liner Lock Knife. Blade of American-made CTS BD1N stainless steel.

8Cr13MoV steel

CORROSION RESISTANCE: 5 EDGE RETENTION: 3  EASE OF SHARPENING: 8

Comparable to AUS-8 but features a bit higher carbon content. Easy to manufacture and being a part of the CR13 series, rich in carbon and chromium, it is basically used for kitchen knives and home scissors.

Cold Steel 62K1 SR1 Lite Folding Knife. Blade of affordable 8Cr14MoV steel.

14C28N steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 4  EASE OF SHARPENING: 6

This Swedish stainless steel is considered an upgrade to their 13C26 steel with an intent of achieving a better rust resistance via adding some nitrogen. A fair mid-range steel that can be made very sharp.

Real Steel Knives H6 Plus Folding knife 3.75″. Blade of Sandvik 14C28N steel.

High End Steel Types

154CM steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 6  EASE OF SHARPENING: 5

A relatively hard steel that has fine edge holding, an excellent level of corrosion resistance (despite having less chromium) and decent toughness good enough for most uses. This steel is also relatively easy to sharpen and used in many premium pocket knives.

Bear OPS Small Bear Song VIII Butterfly Knife. Satin-finished, bayonet blade made from 154CM steel.

ATS-34 steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 6  EASE OF SHARPENING: 5

The Japanese counterpart to the 154CM steel (see above) having very similar characteristics. Good edge retention and fair rust resistance have made it popular with knife makers. 

Dew Hara DH-60B knife. ATS-34 steel blade.

D2 steel

CORROSION RESISTANCE: 2 EDGE RETENTION: 8  EASE OF SHARPENING: 3

Often referred to as “semi-stainless” as it falls just short of the required amount of chromium (13%) to qualify as full stainless steel. Still has a fair corrosion resistance index and is much harder than other comparable steels (better edge retention, but tougher to sharpen).

Kershaw 2076 Strata KVT Pocket Knife. Made from wear resistant D2 high-carbon steel.

VG-10 steel

CORROSION RESISTANCE: 7 EDGE RETENTION: 6  EASE OF SHARPENING: 6

Very similar to 154CM and ATS-34 steels, with a bit more chromium to increase rust resistance and a relish of Vanadium to make it a bit tougher than these two. Relatively hard and easy to sharpen.

Real Steel Huginn EDC Wild And Pocket Knife. Blade Material: VG-10 steel.

H1 steel

CORROSION RESISTANCE: 9 EDGE RETENTION: 2  EASE OF SHARPENING: 8

The expensive Japanese stainless steel is believed to be the ultimate in corrosion resistance (basically does not rust). However, edge retention is (predictably) poor. Good for diving but, of course, not for every day carry knives. 

Spyderco Tasman Salt 2 Pocket Knife. Ultra-corrosion-resistant H-1 steel blade.

N680 steel

CORROSION RESISTANCE: 8 EDGE RETENTION: 5  EASE OF SHARPENING: 6

A relish of nitrogen (0.20%) and a dollop of chromium (17%) ensure this steel’s exceeding rust resistance. This fine-grained steel can take a very fine edge. 

Trauma First Response Tool: 3.4″. Blade Material: Bohler N680 Stainless Steel.

N690 steel

CORROSION RESISTANCE: 4 EDGE RETENTION: 8  EASE OF SHARPENING: 4

This high-end stainless steel has the edge holding of D2 with less toughness and better corrosion resistance. The durable, wear-resistant, hard knife steel is common in many premium knives. 

Amare Knives Paragon Slip Joint Knife. Bohler N690 steel provides a hard blade with excellent wear resistance.

Premium Steel Types

CTS-XHP steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 8  EASE OF SHARPENING: 5

CTS-XHP is another new knife steel with very good hardness and edge retention. A better edge retention results in a more strenuous sharpening. Also, a higher corrosion resistance contributes to a bigger risk of chipping.

Spyderco Techno 2 Pocket Knife. Stonewash finish CTS-XHP stainless blade.

CPM M4 steel

CORROSION RESISTANCE: 2 EDGE RETENTION: 9  EASE OF SHARPENING: 2

A high-efficiency tool steel with excellent toughness and edge retention indices among carbon steels. Crucible’s patented Crucible Particle Metallurgy process provides an exceedingly homogeneous, stable and grindable product featuring outstanding levels of abrasion resistance and toughness.

Benchmade – Bailout Axis Knife. The blade is made of CPM-M4, a super steel, with a corrosion-resistant.

CPM S35VN steel 

CORROSION RESISTANCE: 7 EDGE RETENTION: 7  EASE OF SHARPENING: 5

A superior version of the S30V steel. A finer grain structure and small quantities of niobium improve machine processing properties, toughness and ability to sharpen. Arguably, the ultimate in ‘mainstream’ knife steels with superb edge retention, toughness and stain resistance. 

Zero Tolerance 0452CF; Pocket Knife 4.1”. Knife designer Dmitry Sinkevich. CPM S35VN steel blade shows amazing toughness and resistance to edge chipping, with improved edge retention.

CPM S30V steel

CORROSION RESISTANCE: 7 EDGE RETENTION: 7  EASE OF SHARPENING: 5

This steel has excellent edge retention and withstands rust with ease. It is normally used for high-end pocket knives and expensive kitchen cutlery. The steel is highly regarded for the fine balance of edge retention, hardness and toughness. 

Buck 841 Sprint Pro Knife. The CPM S30V stainless steel blade.

Ultra High End Steel Types

CPM S110V steel

CORROSION RESISTANCE: 6 EDGE RETENTION: 10  EASE OF SHARPENING: 1

This one is the utmost in wear resistance and edge retention. CPM-S110V is expensive, hard to work with and sharpen, but holds edge excellently.

Spyderco Military Folding Knife 4″ .

CPM S30V seemed the logical choice for the blade given its reputation for long-term edge retention and rust resistance.

CPM S90V steel

CORROSION RESISTANCE: 5 EDGE RETENTION: 9  EASE OF SHARPENING: 1

CPM S90V approaches the very peak of wear resistance and edge retention due to the extreme rate of vanadium. It is incredibly expensive and very hard to sharpen but (quite on a par with CPM-S110V) is excellent in holding edge and resisting abrasion. 

Benchmade 535-3 BUGOUT Folding Knife. Blade material: premium CPM S90V super steel.

M390 steel

CORROSION RESISTANCE: 7 EDGE RETENTION: 9  EASE OF SHARPENING: 2

M390 is a new super steel using third generation powder metal technology. Chromium, molybdenum, vanadium, and tungsten in it provide excellent corrosion resistance, very high hardness for superior wear resistance, sharpness and eminent edge retention. It is also a bit easier to sharpen than S90V. 

Microtech Socom Bravo Folding Knife. Bohler M390 steel blade.

M398 steel

CORROSION RESISTANCE: 7 EDGE RETENTION: 9  EASE OF SHARPENING: 2

A modification of the older stainless powder metallurgy M390 steel, crafted primarily via increasing the vanadium and carbon rates. 

Shirogorov Limited Edition RJ Martin Knife. Böhler M398  steel blade.

ZDP-189 steel

CORROSION RESISTANCE: 4 EDGE RETENTION: 8  EASE OF SHARPENING: 1

ZDP-189 is another new super steel containing large amounts of carbon and chromium that secure an excellent level of hardness, providing very high edge retention but at the cost of extreme difficulty in sharpening. The high chromium content (ca. 20%) is mostly amalgamated with carbon to form carbides, so little free chromium is left to withstand corrosion. 

Rockstead SAI-T-ZDP Japanese Folding Knife. ZDP-189 steel mirror finish blade. With proper maintenance, Rocksteads are known to keep a sharp edge for 2-3 years.

Elmax steel

CORROSION RESISTANCE: 5 EDGE RETENTION: 8  EASE OF SHARPENING: 3

Elmax is a high chromium-vanadium-molybdenum steel with extremely high wear and corrosion resistance. Elmax being stainless but performing in many ways like a carbon steel provides very high edge holding and easiness of sharpening making it perhaps the ‘best all round’ knife steel. 

Heretic Knives Custom Colossus OTF AUTO. The blade made from Elmax stainless steel.

CPM-20CV steel

CORROSION RESISTANCE: 7 EDGE RETENTION: 9  EASE OF SHARPENING: 2

CPM-20CV is Crucible’s version of the popular M390 steel. It features a combination of high wear resistance, excellent edge retention and high corrosion resistance due to a high level of chromium. 

Gerber Savvy Folder. Premium CPM 20CV steel.

Popular Applications For Different Types Of Knives

The best knife steel for a particular application depends on several factors, including the intended use of the knife, the user’s skill level, and personal preferences. Here are some examples of knife applications and the recommended types of steel:

Kitchen knives: Kitchen knives are used for food preparation and require a steel that is corrosion-resistant and able to hold a sharp edge well. Stainless steel, such as 440C or VG-10, is often recommended for kitchen knives.

Outdoor/survival knives: Outdoor/survival knives are commonly used for camping, hunting, skinning and cutting. They require a steel that is tough, durable, and able to withstand heavy use. High-carbon steel or tool steel, such as 1095 or D2, are often recommended for survival knives.

Pocket knives: Pocket knives are used for everyday carry and require a steel that is easy to sharpen and able to hold a sharp edge well. Stainless steel or powdered steel, such as S30V or S35VN, are often recommended for pocket knives.

Tactical/military knives: Tactical/military knives are used for combat and other military applications such as self-defense. They require a steel that is tough, durable, and able to pierce effectively. High-carbon steel or tool steel, such as 154CM or CPM-S30V, are often recommended for tactical/military knives.

Hunting knives: Hunting knives are used for skinning and field dressing game. They  also require a steel that is tough and durable. High-carbon steel or Damascus steel are often recommended for hunting knives.

These are just a few examples of knife applications and the recommended types of steel. When choosing the best steel for a knife, it is essential to keep your intended use in mind and make sure that the type of knife steel corresponds with other factors such as toughness and wear resistance.

Manufacturing Considerations

There are some important manufacturing considerations for knife production, which can impact the decision on which knife steel to choose. 

Machinability of different knife steels: Different steels have varying levels of machinability, which is the ability to be cut, drilled, or shaped with ease. Some steels, such as stainless steel, can be more difficult to machine due to their toughness and hardness. Manufacturers must consider the machinability of the steel when selecting the appropriate type for the intended knife.

Heat treatment requirements: Heat treatment is a critical step in the manufacturing process that affects the steel’s properties and ultimately, the knife’s performance. Different steels have varying heat treatment requirements to achieve the desired properties. Manufacturers must follow the correct heat treatment process to achieve the desired performance of the knife.

Compatibility with different manufacturing methods: The manufacturing method used can also affect the choice of steel. Some steels may be more compatible with certain manufacturing methods, such as forging or stamping, than others. Manufacturers must consider the intended manufacturing method when selecting the appropriate steel for the intended knife.

Corrosion resistance requirements: Corrosion resistance is an important consideration for knives that will be used in environments where they may be exposed to moisture, such as in outdoor or kitchen settings. Stainless steel is often the go-to choice for knives that require corrosion resistance, although other types of steel can be coated or treated to improve their resistance.

Surface finish requirements: The surface finish of the blade can affect the knife’s performance and appearance. The manufacturing method used can affect the finish, and some steels may require additional steps, such as polishing or sandblasting, to achieve the desired finish.

By considering these manufacturing considerations, knife manufacturers can select the appropriate steel and manufacturing method for the intended knife and produce high-quality knives that meet the needs and preferences of their customers.

Conclusion

In conclusion, selecting the right kind of knife steel is crucial to producing a high-quality knife that performs well and meets the intended use of the knife. Because if the correct type of steel is not used, it can lead to several manufacturing defects and even design flaws, which can impact how the knife performs in the field. Therefore, its important to consider the choice of steel because it affects the knife’s performance, durability, how it’s manufactured and maintenance requirements.

References

Knife Blade Steels. Blade HQ. https://www.bladehq.com/cat–Steel-Types–332

The Ultimate Guide to Knife Steel. Knife Informer. https://knifeinformer.com/discovering-the-best-knife-steel/