Which is the best steel for kitchen knives?

Steel is an alloy. It is basically a combination of iron and carbon and when no other element is present is called plain carbon steel. Usually, today’s steels contain small amounts of various elements such as Silicon, Manganese, and Vanadium that give to the steel different properties. For example, steels that have added chromium over 12-14% are considered corrosion resistant (labeled as “stainless steels” in the market) or steel that contains manganese have increased strength, toughness and hardenability.

Hardness, in general, is a good thing. The harder the blade the better the edge has (edge stability and edge holding). It is preferably measured using the Rockwell scale (HRC) and commercial kitchen knives typically range between 55-60 HRC.  Usually handmade kitchen knives are hardened more to the 60-65 HRC range or even higher.

Strength: The ability to resist applied forces.

Hardness: The ability to resist permanent deformations.

Toughness: The ability to resist prior to fracturing (also resistibility to cracks /chips when used in heavy duty applications). The harder the steel the less tough it is.

Wear Resistance: The ability to resist wear and abrasion.

Corrosion Resistance: The ability to resist corrosion as a result of reaction with external elements.

Edge Retention: The ability to hold an edge without re-sharpening

Hardenability: The ability of a steel to be hardened through the heat-treating process

Steel performance depends on many factors and many of its properties are inversely proportional to each other.

With that said, when an element is added to the recipe- because we want a specific property – we inevitably sacrifice another one and its properties. Subsequently, we have to trade-off some properties and usually this is between hardness/edge retention and toughness. The bet in knifemaking is to find the best steel, geometry and heat treatment for your knife, in order to perform optimal in specific tasks.

There are some very important elements in knife making that give steel specific properties. Below you will find some of the most important.

Carbon: Increases hardness and strength. Over 0.5% carbon in an alloy is considered “high-carbon”.

Nitrogen: Substitute of Carbon. New technologies use nitrogen in place/ complimentary of carbon to increase hardness.

Chromium: Increases hardenability, corrosion resistance and wear resistance, but in high amounts decreases toughness. Over 12%, a steel is considered “stainless”.

Molybdenum: Increases hardenability, tensile strength, and corrosion resistance.

Nickel: Increases toughness, hardenability and corrosion resistance.

Niobium: Forms very hard but also very small carbides that lead in wear resistance. Keeps the grain small and refines structure.

Vanadium: Increases hardenability and promotes fine grain structure.

Tungsten: Increases wear resistance and is the second strongest carbide* former after vanadium.

*carbide: A compound of carbon and another element.

Steel acquires its properties (see above) through heat treatment. In this procedure the steel is heated in high temperature (called austenitizing temperature) where it changes its structure and then it is quenched in a medium (oil/water/air) in order to “lock” and keep that structure. The new phase of the steel (which is now called martensite) gives us the desired properties of the steel , hardness, strength etc. Then it is tempered (re-heated into lower temperature) to release stresses and define hardness according to our needs. Also, almost all steels benefit from an extra treatment, called “cryo teatment”, where the steel is placed, before tempering, in liguid nitrogen (or even dry ice / alcohol solution) dewar for couple of hours. This procedure, which badly is considered by many an extra (due to cost), helps extract even more hardness ( through carbide precipitation/reduced retained austenite) .

The procedure may sound easy, but it requires perfect timing and preparation as is one of the most crucial steps in the knifemaking process. It requires countless hours of testing, knowledge of metallurgy and proper equipment.

Choose a kitchen knife based on performance and looks. Beauty is something subjective, so I will focus and analyze on the performance. Performance depends on many factors, and some of them, unfortunately, are inversely proportional to each other so choose a knife based on your needs.

Define your needs by asking yourself some questions and consider:

What task do you want to perform? light tasks(vegetables, boneless proteins etc) or hard tasks? Slicing or paring?

Are you familiar with sharpening a knife?Do you enjoy it?

Is it going to be used for pull / push cut, chopping or rocking?

Will you work it for hours? Or will be something for special occasions?

Knife performance factors

A knife’s performance directly depends on factors such as steel, heat treatment, blade geometry, thickness behind the edge and sharpening angle while depends indirectly with weight and knife shape.

Steel

The choice of a steel must be done depending whether you search for edge retention, toughness, sharpenability, fine or coarse edge, stainless or not etc.

A high alloy steel that has high carbide volume ( Vanadium, Niobium, Tungsteen and more) along with high hardness will have the greatest edge retention/ wear resistance, will take a coarser edge, but somewhat decreased toughness and more difficulties sharpening.

A low alloy steel with few impurities (Sulfur/ Phosphorus) will take the finest edge, have increased toughness ( due to absence of carbides and grain size) and easier sharpening but low wear resistance.

On the above two categories we have sub categories of stainless and non stainless steels. An increase in chromium ( and/or molybdenum) will have a direct effect on the performance of these steels. Generally speaking, the more stainless the less tough, the coarser the edge, the more difficult to sharpen but the greater stain resistance and edge retention will have.

Heat Treatment

Heat treatment directly affects all of these properties of the steel (stain resistance/ wear resistance/ toughness etc). Unfortunately it cannot be analyzed in few words (paragraphs or even better, pages), but have in mind that you cannot compare directly two steels because a steel that has “more of X element than Y” or even “more of that X element than the other steel” . Heat treatment affects hardness/ edge retention , toughness, corrosion resistance so  it has the final word in the end product. With that said, a steel in 62HRC can outperform (in terms of edge retention or toughness) a steel in 64HRC depending whether it is high alloy or low alloy and depending the use.

Geometry

The typical blade geometries are convex, hollow, flat, “S”  and combination of these. Depending the geometry and the spine thickness the knife will have greater resistance while cutting, better or worse edge stability, food release etc. 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 (and some rare) kitchen knife steels available mostly in the handmade knife 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. Please note that some good/average steels may perform exceptionally (and even better from more expensive and high end steels) depending the use and type of knife. Also the following listing is based mostly on the wear resistance /edge holding of a steel rather than edge stability or toughness.

Top options

Premium, high wear resistant stainless steels, that take a good edge (often referred as super steels).

MAGNACUT : The latest development in cutlery steels, MagnaCut is manufactured with PM metallurgy that means great purity and grain size. It features an amazing toughness to edge retention ratio which means that is top choice for those fine kitchen knife edges.

ELMAX : A high-end, steel alloy which is considered a super steel. 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.

SG2: A high end alloy steel from Takefu Japan with very good wear resistance that can take an exceptional edge. One of my favorites for kitchen knives as it provides good balance.

S60V / S90V/ S110V/ S125V : Crucible manufactures a series of high-end alloy steels with amazing edge retention abilities. 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. The larger the number of the steel, the more wear resistant (60<90<110<125) which mean difficult machining, polishing and sharpening. Preferably used on kitchen knives that take heavy work load with -not so- acute edges.

M390 :  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. Equivalents CPM 20CV / CTS 204P.

–NON stainless (Carbon) steels-

Apex Ultra : New knife steel developed especially for handmade knives. Low alloy with fine carbides make this steel easy to forge and sharpen. Well-balanced steel that has the highest toughness of all knife steels (in the 66+ HRC range). Top choice.

ZDP-189 : Non stainless, high chromium carbide super steel  from Hitachi. It can achieve extreme hardness of 64-67 HRC (contains very high amounts of carbon – 3%) and holds excellent edge for a long time. It is considered  difficult to sharpen and chips easily in those high hardness values. It contains very high amounts of chromium (20%) so it is promoted as stainless but in fact it is not as it forms chromium carbides.  Moderately hard to find cause of the manufacturer’s (Hitachi) strict policy to heat treatment (must be made in-house/ specific heat treating spots etc). Equivalent MC66. Used mostly on knives that must have a long lasting edge with moderate toughness.

CPM M4 : Non stainless, high alloy, high toughness steel (popular in cutting competitions) produced with Particle Metallurgy process, with working hardness 62-64 HRC. High levels of Molybdenum (hence the M in the M4). Excellent edge retention.

Shirogami 1 or White 1 (Hitachi): Very pure and famous steel for Japanese kitchen knives as it takes the finest edge among the Aogami/ Shirogami steel series. 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.

Shirogami 2 or White 2 (Hitachi): Same steel as White 1 but with 0,10-0,30% less Carbon. Achieves great hardness and support excellently thin edges, a little bit tougher than white 1.

Shirogami 3 or White 3 (Hitachi): Same steel as White 2 but with 0,15-0,35% less Carbon. 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)

Aogami 2 or Blue 2 (Hitachi): Virtually the same as Aogami 1 but a little bit tougher and less wear resistant/ edge holding.

Aogami Super or Blue super (Hitachi):  The best edge holding among the other two Aogami steels. 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.

In conclusion, the Shirogami / white steels take the best edge with white 1 to take the finest edge and white 3 being the toughest. The Aogami / Blue steels have the best edge retention with blue super being the most wear resistant and blue 1 being the most tough.

Very Good options:

Upper range steels. These are considered great for making knives by many knifemakers.

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. 13C26 is similar (essentially the same) to AEB-L, steel developed for razor blades too. 14C28N is an improvement of 13C26 basically in the corrosion resistance department. Another steel that is similar and can fit in this “category” is 12c27 which is also a similar steel to 13C26/ AEB-L, with more Chromium (better corrosion resistance) and less Carbon (less wear resistance) though.

Niolox/SB1 : Good wear resistance, fine grained steel with decent toughness and easy to sharpen. It has 12,7 % Chromium that makes is stainless (or better, more stain resistant). Contains Niobium and Vanadium, which are great carbide formers.

CPM S30V, S35VN & S45VN : S30V was designed as a cutlery steel. Very good edge retention, good toughness for stainless and moderate easy to sharpen. S35VN is an “improved” version of S30V that hit the market in 2009.It is a bit tougher and has good corrosion resistance but has reduced edge retention. S45VN is the newest improvement (2019) with better edge retention than S35VN but slightly worse toughness. Better toughness than S30V (in higher hardness also).

154CM : A high carbon, stainless steel with Molybdenum added. It is preferred because it provides better edge retention in comparison with the other stainless steels.it is moderately hard to sharpen. The Japanese equivalent is ATS-34.

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. It is moderate hard to sharpen.

VG-10 / VG-10 Cobalt:  Stain resistant steel that can achieve great hardness and very sharp edge. It doesn’t have great toughness though and it is prone to chipping especially in acute angles, but overall  is one very famous and favorite cutlery steel. There are two producers Takefu (Japan) which produces the VG10 and Ahonest Changjiang (China) which produces VG10 Cobalt. Their element composition is virtually the same.

440C : Probably the most well-known stainless steel out there. This happens to be to every household somehow and you probably used it at least once in your lifetime. Very corrosion resistant, good toughness and decent wear resistance, it doesn’t achieve the finest edge though.  Equivalents Bohler – Uddeholm N695 / Carpenter CTS-40P and more

–NON stainless (Carbon) steels-

1095 : This is a very simple, high carbon steel popular among knifemakers because it can be worked easily. It forms great hamon (differential hardening), rusts easily and doesn’t hold an edge very well comparing to other, alloy steels. Sharpens easy. Equivalent: UHB20C

W1 : Famous steel among knifemakers as it is easy to work with and creates fine edge. Good wear resistance for non stainless steel and good toughness depending on the heat treatment. Can be hardened to about 65 HRC. W2 is similar steel with a little more Vanadium.

52100 : Famous forging steel (also called ball bearing), usually used on hunting knives due to good toughness and decent wear resistance on high hardness. Has some minor applications on kitchen knives.

Average – Lower options:

Lower range steels: These steels are usually made for budget knives or specialized uses. Many of them are considered “good value for money” and some of them, may, under specific conditions perform (visually or on the field) very well.

N690 : Similar to VG10 with slightly higher amount of Chromium and Carbon. Stainless with slightly improved edge retention than VG10. Popular blade steel used from companies for mass production knives.

N680 :  Steel that was designed for high corrosion resistant applications like diving knives. Doesn’t harden enough for a good kitchen knife though.

VG-1 / O1 / 420 /420HC / 420J / 420J2 / 440A /440C / ATS-8A / 425M

Special Category:

The following steels have shown extreme wear resistant and edge holding capabilities. They are very (to extremely) hard to grind, polish and sharpen. The higher the hardness the lower the toughness.

CPM Rex 121: The king of wear resistance. It can achieve an amazing of 72 HRC with immense amount of carbides (about 25%). It is extremely difficult to sharpen at higher hardness.

Z max: Made with PM technology this steel can achieve hardness of 71 and show extreme edge holding. Low toughness though, as expected. Not stainless.

CPM 15V: Super wear resistant as well. With Carbon 3,4% and Vanadium about 15% is on the top wear resistant steels out there. Not stainless.

HAP72: Another high carbide steel from Hitachi. Can achieve hardness of 70 HRC and has extreme wear resistance capabilities.

Maxamet: Not stainless, high carbide steel that is top in wear resistance as well.

Damascus steel is made by forge welding two or more steels. The idea is to heat and weld the steel, create a pattern, acid etch the blade and create a nice aesthetic and eye pleasing result. Originally Damascus steel was originated from today’s India and Pakistan area and nowadays its “secret technique” is considered lost. At that time, the welding technique helped distributing impurities of the steel evenly and therefore creating a better/stronger blade. The Damascus blades are not considered top performance kitchen knives because of the poor performance steels used to make the patterns. Of course, there are some rare exceptions of damascus performing brilliantly!

A great example is the work of Damasteel which makes Damascus patterned steel with PM technology combining RWL 34 steel with PMC27 (for their DS93X variation). The final result is a very pure, fine grained stainless steel that performs amazingly, highly recommended!

4 different Damascus pattern examples