knife steel guide for the average line cook of below-average intelligence

[iimi]

One of my coworkers (@Shawndg5) asked me to write him a basic guide to knife steels, so he could look around for knives and have a basic idea of what he was looking at. Some other industry friends have echoed his thoughts, so I typed this up between clopens and mostly inebriated. I don't have experience with all of these steels, so if you guys have any additional info or anything I got blatantly wrong, please correct me. Excuses aside, here it is: the

knife steel guide for the average line cook of below-average intelligence

Basic knowledge to keep in mind:
Steel type is an easy thing to fixate on, but please remember— it's not very important in the overall knife design. Grind, profile, heat treat, and comfort are all more important factors in knife usage.

Simple metallurgy terminology:

• HRC: the scale that we measure hardness of the steel on. Most Japanese kitchen knives are going to land somewhere in the range of 58 to 66 HRC. German knives could be anywhere from the low 50s to 58 on the high end.
• Toughness: in the context of a knife steel, toughness is used to describe the metal's resistance to chipping. Basically, a brittle steel is one lacking in toughness, and vice versa. Toughness has just as much, if not more, to do with heat treatment as with steel type/composition.
• Heat treatment: to make a knife, steel has to be brought to a high temperature, then rapidly cooled to change the structure of the steel. This creates a very hard but also very brittle steel. In order to make this usable, it is tempered at a lower temperature without the rapid cooling, therefore toughening the steel.
• Carbide: Steel is basically composed of very hard carbides (particles composed of iron and carbon molecules, at its simplest) suspended in a matrix of the softer iron. These carbides are what do the cutting work. Different steels will have differently behaving carbides— some have large carbides that create a "toothy" edge, which can be nice on tough produce like tomato or pepper skins and create "bite." Other steels will have very fine, evenly dispersed carbides, which can create smooth, glassy cuts on, for example, raw fish.
• Alloy: Different alloys of steel have different additive elements/compounds to create or enhance certain properties of the steel. Steel at its simplest form is a combination of iron, Fe, and carbon, C. A common additive is chromium, which helps prevent rust and staining.

Stainless steels:
Stainless comes in a very broad range of characteristics, from German and Chinese low-HRC steels to modern powdered metal (PM) super steels.

• AUS8: A very basic/generic steel with lower hardness for Japanese knives, but still often outperforming German stainlesses. Typically seen at around 58-59 HRC. Tough, slightly gummy to sharpen (read: tougher for beginners to deburr) and with low edge retention.
• AUS10: A small compositional change from AUS8, but in my opinion, a large upgrade in terms of useability in the kitchen. Still retaining good toughness, but the increased carbon also means more carbides formed. Usually harder than AUS8, probably 59-61 HRC, and a good, toothy edge. Not the worst steel to deburr, not the easiest. No complaints with this steel. I think this is an underrated one.
• AEB-L: Fine-grained steel, relatively small carbides and easy to sharpen. Very usable steel, holds a more refined edge than the previous steels. Wider range of HRC on this one.
• Ginsan (G3, Silver 3): Popular stainless among both blacksmiths and cooks. For a stainless, this is a pretty easy to sharpen steel, usually sitting at around 62 HRC. Often draws comparisons to shirogami steels.
• HAP-40: Very hard powdered metal that gets insanely hard, one of the best edge retention knife steels currently commonly offered. Considering the high HRCs (high 60's), a tough steel, as well. Tough to sharpen, as you can imagine. Also technically not a full stainless.
• R2 (SG2): A powdered metal that can get really hard, takes and holds a sharp edge for a long time. Can be hard to sharpen, due to its hardness.
• SLD (SKD 11): The Japanese version, simply put, of D2. Large carbides, hard to deburr. Can be chippy due to the size of the carbides. Again, not a full stainless.
• SKD (SKD 12): Japanese version of A2. Finer carbides than SLD, but still a nice, toothy edge. Tougher due to the carbide volume difference. Not a real stainless. One of my favorite steels.
• VG10: A much maligned steel due to its advertised use in cheap factory made knives, VG10 is a stainless steel that can be very good in the hands of the right blacksmith, just like most of the other knives in this guide. Usually found in the 60-62 HRC range, a toothy edge, and usually not the easiest steel to deburr.
• ZDP-189: Take HAP-40 and make it even harder to sharpen, but also a little more stainless. And a little less tough.

Carbon steels:

• White #1 (Shirogami #1): A very pure carbon steel with few additives and a high carbon content, this stuff gets pretty hard but also can be fragile. At lower HRCs, it tends to have worse edge retention than other carbon steels at similar hardnesses. Very, very, very easy to sharpen, and gets very sharp, with a very refined edge.
• White #2 (Shirogami #2): A popular steel, sort of the comparison standard. Easy to sharpen, gets very sharp, tougher than white 1 steel but usually found at lower hardnesses, around 62.
• Blue #1 (Aogami #1): Similar to white 1, but with slightly greater edge retention and toughness.
• Blue #2 (Aogami #2): Similar to white 2, but with slightly greater edge retention and toughness.
• Aogami Super (AS): Usually harder than Blue #2, with a toothier edge due to added Vanadium and Molybdenum. The longest edge retention of the blue steels, also a very popular steel choice.

 

[Delat]

More carbons: 52100, vtoku2, 1.2419, 1.2519, 26c3 / spicy white, 80crv2, apex ultra

More stainless: Magnacut, SF100

 

[blokey]

Consider the broader market right now also include "German steel" aka Din 1.4116 aka X50CrMoV15, which is often advertised as some high end stainless steel, used by Zwilling and Wusthof, in reality it's really not that good, even their supposed strong suit toughness is pretty bad compare to higher hardness stainless steel s. There's also the 9Cr18MoV and 9Cr15MoV, basically Chinese equivalent to 440C, there's also 10Cr15CoMoV, which is Chinese equivalent to VG10, you often saw them labeled as VG10 on Amazon and AliExpress. They could be fine steel proven heat treat correctly, but sadly that's often not the case.

 

[coxhaus]

I know you guys' list all the German steel as the same but all their knives do not work the same as far as edge retention if I have that term right. I had a lower line Henckels knife and it will not hold an edge the same as the Henckels 4 stars and 5 star knives. Also, within the Henckels knives I have some of the older ones which the steel will pit easier than others. I now have 2 of these older Henckels with wooden handles that are this way. I recently found a 10-inch on eBay. I also have an 11.5 inch one. I guess part of it could be heat treatment and/or a little difference in the steel over the years. I know not but I know there is a difference.

I don't buy the lower line German knives.

 

[JASinIL2006]

One of my coworkers (@Shawndg5) asked me to write him a basic guide to knife steels, so he could look around for knives and have a basic idea of what he was looking at. Some other industry friends have echoed his thoughts, so I typed this up between clopens and mostly inebriated. I don't have experience with all of these steels, so if you guys have any additional info or anything I got blatantly wrong, please correct me. Excuses aside, here it is: the

knife steel guide for the average line cook of below-average intelligence

Basic knowledge to keep in mind:
Steel type is an easy thing to fixate on, but please remember— it's not very important in the overall knife design. Grind, profile, heat treat, and comfort are all more important factors in knife usage.

Simple metallurgy terminology:

• HRC: the scale that we measure hardness of the steel on. Most Japanese kitchen knives are going to land somewhere in the range of 58 to 66 HRC. German knives could be anywhere from the low 50s to 58 on the high end.
• Toughness: in the context of a knife steel, toughness is used to describe the metal's resistance to chipping. Basically, a brittle steel is one lacking in toughness, and vice versa. Toughness has just as much, if not more, to do with heat treatment as with steel type/composition.
• Heat treatment: to make a knife, steel has to be brought to a high temperature, then rapidly cooled to change the structure of the steel. This creates a very hard but also very brittle steel. In order to make this usable, it is tempered at a lower temperature without the rapid cooling, therefore toughening the steel.
• Carbide: Steel is basically composed of very hard carbides (particles composed of iron and carbon molecules, at its simplest) suspended in a matrix of the softer iron. These carbides are what do the cutting work. Different steels will have differently behaving carbides— some have large carbides that create a "toothy" edge, which can be nice on tough produce like tomato or pepper skins and create "bite." Other steels will have very fine, evenly dispersed carbides, which can create smooth, glassy cuts on, for example, raw fish.
• Alloy: Different alloys of steel have different additive elements/compounds to create or enhance certain properties of the steel. Steel at its simplest form is a combination of iron, Fe, and carbon, C. A common additive is chromium, which helps prevent rust and staining.

Stainless steels:
Stainless comes in a very broad range of characteristics, from German and Chinese low-HRC steels to modern powdered metal (PM) super steels.

• AUS8: A very basic/generic steel with lower hardness for Japanese knives, but still often outperforming German stainlesses. Typically seen at around 58-59 HRC. Tough, slightly gummy to sharpen (read: tougher for beginners to deburr) and with low edge retention.
• AUS10: A small compositional change from AUS8, but in my opinion, a large upgrade in terms of useability in the kitchen. Still retaining good toughness, but the increased carbon also means more carbides formed. Usually harder than AUS8, probably 59-61 HRC, and a good, toothy edge. Not the worst steel to deburr, not the easiest. No complaints with this steel. I think this is an underrated one.
• AEB-L: Fine-grained steel, relatively small carbides and easy to sharpen. Very usable steel, holds a more refined edge than the previous steels. Wider range of HRC on this one.
• Ginsan (G3, Silver 3): Popular stainless among both blacksmiths and cooks. For a stainless, this is a pretty easy to sharpen steel, usually sitting at around 62 HRC. Often draws comparisons to shirogami steels.
• HAP-40: Very hard powdered metal that gets insanely hard, one of the best edge retention knife steels currently commonly offered. Considering the high HRCs (high 60's), a tough steel, as well. Tough to sharpen, as you can imagine. Also technically not a full stainless.
• R2 (SG2): A powdered metal that can get really hard, takes and holds a sharp edge for a long time. Can be hard to sharpen, due to its hardness.
• SLD (SKD 11): The Japanese version, simply put, of D2. Large carbides, hard to deburr. Can be chippy due to the size of the carbides. Again, not a full stainless.
• SKD (SKD 12): Japanese version of A2. Finer carbides than SLD, but still a nice, toothy edge. Tougher due to the carbide volume difference. Not a real stainless. One of my favorite steels.
• VG10: A much maligned steel due to its advertised use in cheap factory made knives, VG10 is a stainless steel that can be very good in the hands of the right blacksmith, just like most of the other knives in this guide. Usually found in the 60-62 HRC range, a toothy edge, and usually not the easiest steel to deburr.
• ZDP-189: Take HAP-40 and make it even harder to sharpen, but also a little more stainless. And a little less tough.

Carbon steels:

• White #1 (Shirogami #1): A very pure carbon steel with few additives and a high carbon content, this stuff gets pretty hard but also can be fragile. At lower HRCs, it tends to have worse edge retention than other carbon steels at similar hardnesses. Very, very, very easy to sharpen, and gets very sharp, with a very refined edge.
• White #2 (Shirogami #2): A popular steel, sort of the comparison standard. Easy to sharpen, gets very sharp, tougher than white 1 steel but usually found at lower hardnesses, around 62.
• Blue #1 (Aogami #1): Similar to white 1, but with slightly greater edge retention and toughness.
• Blue #2 (Aogami #2): Similar to white 2, but with slightly greater edge retention and toughness.
• Aogami Super (AS): Usually harder than Blue #2, with a toothier edge due to added Vanadium and Molybdenum. The longest edge retention of the blue steels, also a very popular steel choice.

That is a nice and simple explanation! Question: in your discussion of SLD and SKD, you make reference to D2 and A2, but don't see them defined anywhere... what are D2 and A2?

 

[coxhaus]

D2 and A2 steels were US steels used in hunting knives a long time ago. D2 is Knives of Alaska and Randal RAT and A2 are knives from Bark River. I am sure there are others but that is what comes to mind right now. I own several. From what I have seen is the A2 develops a little more patina than the D2 over the 15 years I have owned them. I have not seen patina on D2.

I have not seen chipping, but the edge is not as thin or as great of sharpening angle as a kitchen knife. Yes, they would be more chippy that a 1095 steel.

 

[Troopah_Knives]

Great work! I'd like to offer a few slight tweaks

Toughness has just as much, if not more, to do with heat treatment as with steel type/composition

Toughness is much more steel-dependent then HT dependant (assuming the company isn't doing anything totally insane). Personally, I would remove this.

Fine-grained steel, relatively small carbides and easy to sharpen.

AEB-L doesn't have any finer or less fine grain than most other steels. It does have some of the finest carbides out there (finer than white 1).

Ginsan (G3, Silver 3): Popular stainless among both blacksmiths and cooks. For a stainless, this is a pretty easy to sharpen steel, usually sitting at around 62 HRC. Often draws comparisons to shirogami steels.

While Ginsan does draw comparisons to shiro class steels as far as I can tell this is mostly due to the compositional similarities and really doesn't have anything to do with the properties so it might make sense to remove this to avoid confusion

Can be hard to sharpen, due to its hardness.

SG2 can be hard to sharpen due to its vanadium carbides it doesn't really get harder than other steels.

toothier edge due to added Vanadium and Molybdenum

Tungsten and Vanadium

Once again fantastic work this was a great read! Would it not make sense to add a Semi-stainless section so the non-stainless and stainless high alloy steels aren't mixed?
.

 

[Troopah_Knives]

SF100

SF100 = AEB-L right?

 

[jedy617]

Nice summary, besides a few additions like Troopah mentioned. In the pocket knife world, we see AUS-10 as very chippy, and AUS-8/AUS-10 being very subpar budget steels, nothing you would pay more than $50-$100 for on a knife. Always interesting to see other users takes for knives in different forms. I know people love the JKI gesshin knives with AUS-8 and AUS-10 here and no one bats an eye. If a company uses AUS-8 in a pocket knife over $30 people freak out haha, vice versa for AUS-10 over about 100-150.

 

[Barmoley]

Nice summary, besides a few additions like Troopah mentioned. In the pocket knife world, we see AUS-10 as very chippy, and AUS-8/AUS-10 being very subpar budget steels, nothing you would pay more than $50-$100 for on a knife. Always interesting to see other users takes for knives in different forms. I know people love the JKI gesshin knives with AUS-8 and AUS-10 here and no one bats an eye. If a company uses AUS-8 in a pocket knife over $30 people freak out haha, vice versa for AUS-10 over about 100-150.

Yet same people will rave and sing praises to how great and tough 1095 is, so what does that say about people's abilities to judge steel qualities from using knives.

 

[coxhaus]

I think 1095 is tough as it will bend rather than break like some of these super steels.

 

[jedy617]

Yet same people will rave and sing praises to how great and tough 1095 is, so what does that say about people's abilities to judge steel qualities from using knives.

Well usually I only hear about boomers liking 1095 for camp knives/fixed blades, different group of people. Don't know anyone in my pocket knife circle (150 or so) who will buy AUS-8. But yeah I totally admit there is warped thinking on lots of steels.

 

[blokey]

I know you guys' list all the German steel as the same but all their knives do not work the same as far as edge retention if I have that term right. I had a lower line Henckels knife and it will not hold an edge the same as the Henckels 4 stars and 5 star knives. Also, within the Henckels knives I have some of the older ones which the steel will pit easier than others. I now have 2 of these older Henckels with wooden handles that are this way. I recently found a 10-inch on eBay. I also have an 11.5 inch one. I guess part of it could be heat treatment and/or a little difference in the steel over the years. I know not but I know there is a difference.

I don't buy the lower line German knives.

I'm not listing all the German steel the same, Im specifically referring to the marketing term "German steel" which refers to Din 1.4116, and heat treatment makes a large difference in edge retention. Lower end German stuff could use 3cr13 which is the bottom of the barrel stuff as far as knife steel go.

 

[coxhaus]

Super steels have other properties than bending so it is a tradeoff.

 

[jedy617]

@Troopah_Knives I liked your steel Saturday post about ginsan. I am quite new to the steel and there is not much data on it or 19c27 from Larrin. Edge retention wise where we would put it? I'm assuming somewhat less than vg10, but more than Hitachi white and blue as it has less carbide forming elements, compared to vg10 but much more (although be it softer chromium carbides) compared mainly to blue and white? I'm guessing similarly for toughness it would fall somewhere in that range or is this flawed reasoning?

 

[Barmoley]

I think 1095 is tough as it will bend rather than break like some of these super steels.

But it really isn't tough at all. It is one of the most brittle steels commonly used in knives. Manufacturers get around it by using thick geometry or heat treating it relatively soft at which point it is tough enough so it bends instead of breaking.

I don't like the term "supersteels", since that really doesn't say anything about any particular quality of the steel. Many high alloy steels are much tougher than 1095.

 

[blokey]

TBH with Din 1.4116 there's not much of a trade off in anything, in its typical heat treatment it has worse edge retention and toughness than 14c28n, Aeb-L, Aus8 and even many of the "super steels". The toughness of mainstream German knives seems come more from being thick rather than the steel, I would love to see German manufacturers switch to something like Aeb-l in the future.
Courtesy of Larrin
https://knifesteelnerds.com/2021/10...ness-edge-retention-and-corrosion-resistance/

 

[coxhaus]

Nice. I don't chase steel anymore. I haven't in many years.

Looks like D2 and A2 steel are missing? 1095.

 

[Troopah_Knives]

@Troopah_Knives I liked your steel Saturday post about ginsan. I am quite new to the steel and there is not much data on it or 19c27 from Larrin. Edge retention wise where we would put it? I'm assuming somewhat less than vg10, but more than Hitachi white and blue as it has less carbide forming elements, compared to vg10 but much more (although be it softer chromium carbides) compared mainly to blue and white? I'm guessing similarly for toughness it would fall somewhere in that range or is this flawed reasoning?

I believe he has a data toughness data point on 19c27. Its gonna be a touch less wear-resistant then vg-10 and a bit more then 14c28n. The important part is that micrographs of 19c27 show very chunky carbides.

Looks like D2 and A2 steel are missing?

SLD = D2 SKD = A2

 

[M1k3]

"Super steels" translation: "super hard to sharpen on regular stones for most people steel"

 

[ReiHamono]

Can anyone explain the big deal about Apex Ultra?

 

[coxhaus]

"Super steels" translation: "super hard to sharpen on regular stones for most people steel"

Yes, in the old days it was very hard to sharpen. I used a Gerber steel to sharpen with and stones to finish on. I have the original Gerber steel that came out when they were made in the US. No diamond stones and no Worksharp sharpener.

 

[jedy617]

I believe he has a data toughness data point on 19c27. Its gonna be a touch less wear-resistant then vg-10 and a bit more then 14c28n. The important part is that micrographs of 19c27 show very chunky carbides.

SLD = D2 SKD = A2

Interesting, I really expected ginsan to be relatively finer carbide wise. So toughness wise would we be around vg-10?

 

[blokey]

Can anyone explain the big deal about Apex Ultra?

Very good toughness at high hardness, really good wear resistance for a low alloy steel. Also relatively easy to forge and heat treat for most blade smith. Sharpening one of those feels very smooth and creamy to me, almost feel like white than blue super .

 

[coxhaus]

But it really isn't tough at all. It is one of the most brittle steels commonly used in knives. Manufacturers get around it by using thick geometry or heat treating it relatively soft at which point it is tough enough so it bends instead of breaking.

I don't like the term "supersteels", since that really doesn't say anything about any particular quality of the steel. Many high alloy steels are much tougher than 1095.

Yea, Buck knives tried 440C steel years ago and went back to 420 steel with good heat treatment. I have some of both. Heat treatment seems to bring out the best in some steels.

 

[Delat]

SF100 = AEB-L right?

Hmmm, I thought it was different but seems close enough to call it the same
SF100: .67% carbon and 13.02% chromium

 

[Troopah_Knives]

Interesting, I really expected ginsan to be relatively finer carbide wise. So toughness wise would we be around vg-10?

The one data point I have seen has it much higher in toughness probably because it has a lower carbide volume. This page has the micrographs

 

[superworrier]

Can anyone explain the big deal about Apex Ultra?

I think the main takeaway is there hasn't been any recent modern research into forgeable low-allow steel for high end knives with new technology, and thus most existing steels fall short in comparison

 

[iimi]

Great work! I'd like to offer a few slight tweaks

Toughness is much more steel-dependent then HT dependant (assuming the company isn't doing anything totally insane). Personally, I would remove this.

AEB-L doesn't have any finer or less fine grain than most other steels. It does have some of the finest carbides out there (finer than white 1).

While Ginsan does draw comparisons to shiro class steels as far as I can tell this is mostly due to the compositional similarities and really doesn't have anything to do with the properties so it might make sense to remove this to avoid confusion

SG2 can be hard to sharpen due to its vanadium carbides it doesn't really get harder than other steels.

Tungsten and Vanadium

Once again fantastic work this was a great read! Would it not make sense to add a Semi-stainless section so the non-stainless and stainless high alloy steels aren't mixed?
.

Will get around to all of this when I'm not at work or drinking after work, could be weeks who knows. Also, I didn't add a semi-stainless category because I got lazy and also wasn't sure which steels that kinda walk the like between stainless and semi-stainless would go where, and I was done using my brain for the time being. Nice to have a solid fact check source, thanks.

 

[Dan-]

Take this how you will, but your writing seems far more sophisticated than your average line cook can understand.

For example, “HAP-40: Very hard powdered metal that gets insanely hard” and I wonder if that HAP40 is after the new hostess.