Stainless Steel Chart Comparison EDC Knife Blades v5.5

[KennethW]

Stainless Steel Chart Comparison EDC Knife Blades v5.5

Last Updated 17th September 2019

This Chart compares different Steels and various attributes, to benchmark their performance. If you are confused with all the different types of steels that manufacturers put on their knife blades, this article will help shed 'some' light on the topic.

By kennethw

*more steels and measures will be added to the chart in future, as well as toughness and sharpness attributes.

x-axis = price
y-axis = rating


Disclaimer:
This post is based purely on my opinion and my analysis of various resources both cited in my references and through my experience with the steels. I apologize beforehand if any of the below information has any inaccuracies. I am no Engineer, nor pretend to be one, I am in fact a Government Statistician, but I have a love for knives and blade collecting. Therefore, please use this post purely as an FYI, and NOT as a resource or guide.

Methodology:
Each attribute is ranked from best to worst, and given a numerical value/rating between 1-10 based on its rank in the chart, rank is determined by a combination of the general consensus (Corrosion Resistance from Crucible and various Data Sheets, Hardness from Rockwell tests and Edge Retention CATRA tests, Wear Resistance from SimpleToolSteel Data Sheet) from resources cited in my references. The rating is then divided by the number of attributes measured, as more attributes are added to the chart in future, the individual attribute ratings will change accordingly. All attribute ratings are then aggregated into a total rating for that steel. The maximum sum of all attribute values will always equal to 10. While this post is a crude and oversimplification of the steels mentioned, it should provide an idea of how the specific steels perform when compared to others.



For the purpose of this post, we will only be looking at Stainless Steel, as it is the most common steel found in EDC blades today.

Steel is an alloy of primarily iron and other trace compounds. Carbon has been the main material used in most steel alloys, however other alloying elements like Vanadium, Tungsten, Chromium, Manganese, Molybdenum, Silicon, Boron, Sulphur, Nickel, Aluminium, Cobalt, Copper, Cerium, Niobium, Titanium, Tin and occasionally even Zirconium are used to manipulate Strength, Hardness, Toughness, Wear Resistance, Corrosion Resistance, Edge Retention and Sharpness.

By kennethw

Here is a brief example of the different element types and how they affect Stainless Steel:


Element / Primary function

Carbon (C)

• Increases edge retention and raises tensile strength.
• Increases hardness and improves resistance to wear and abrasion.

Chromium (Cr)

• Increases hardness, tensile strength, and toughness.
• Provides resistance to wear and corrosion.

Cobalt (Co)

• Increases strength and hardness, and permits quenching in higher temperatures.
• Intensifies the individual effects of other elements in more complex steels.

Copper (Cu)

• Increases corrosion resistance.

Manganese (Mn)

• Increases hardenability, wear resistance, and tensile strength.
• Deoxidizes and degasifies to remove oxygen from molten metal.
• In larger quantities, increases hardness and brittleness.

Molybdenum (Mo)

• Increases strength, hardness, hardenability, and toughness.
• Improves machinability and resistance to corrosion.

Nickel (Ni)

• Adds strength and toughness.

Niobium(Nb)

• Stabilizes carbon.
• Strengthens steel at high temperatures

Nitrogen (N)

• Used in place of carbon for the steel matrix.

Phosphorus (P)

• Improves strength, machinability, and hardness.
• Creates brittleness in high concentrations.

Silicon (Si)

• Increases strength.
• Deoxidizes and degasifies (if thats even a word) to remove oxygen from molten metal.

Sulfur (S)

• Improves machinability when added in minute quantities.

Tungsten (W)

• Adds strength, toughness, and improves hardenability.

Vanadium (V)

• Increases strength, wear resistance, and increases toughness.

Note of Caution: The Steel used is not the exclusively the only determinant in blade performance. One has to take into account if the blade has been properly Heat Treated, the design and geometry of the blade, the design of the handle, the dimensions, the weight, and the overall build quality of the entire product.

By kennethw


As mentioned above, there are several attributes that determine the Steel. Let’s take an in depth look at these attributes, and how they will play an important role in the choice of you blade.


Tensile Strength:
Strength or Tensile Strength which is the maximum stress the steel can withstand while being stretched or pulled before necking or deforming.

Hardness:
The stress applied to the tip or edge of the blade before the edge curls or deforms will dependent on the hardness of the steel. The harder the steel, the more resistant to deforming it is. The Rockwell test is commonly used to determine the hardness of steels.

Toughness:
The blades resistance to damage like chipping, cracking or breaking will be determined by its Toughness.

Wear Resistance:
The ability to withstand abrasion. Carbides distribution within the steel matrix is usually the main determinant of Wear Resistance.

Corrosive Resistance v1:
All steel, even Stainless Steel is not immune to corrosion. Oxidation at the surface of the blade steel will lead to rust formations.

Corrosive Resistance v2:
New Chart! Using a modified PREN with Carbon and Vanadium formula modifications, instead of v1 which relies on user testing. In this new v2 chart, the values a logarithmic, and a steel with 20 is twice as corrosion resistant as 10, and 40 is twice as resistant as 20, so on an so forth.

*Always remember that heat treatment, finishing and other factors can also play a big role in corrosion resistance.

Edge Retention:
The ability to stay sharp. Losing the edge on your blade can be attributed to several factors, mainly edge deformation, chipping, corrosion or oxidative stress. Knowing the task you will use your blade for, and selecting appropriate steel will help keep your blade sharp for longer.
*edge retention for this article is based of a stabilized working edge, rather than a hair popping razor edge.

Sharpness:
The ‘fine-ness’ of the grain will determine how sharp you will be able to sharpen your blade. The grain is affected by both the methodology in the forging process and the elemental additives used in the alloy.

Ease to Sharpen:
This is not part of the comparison chart, however it gives us an indication of how easy it is to sharpen a blade depending on the type of steel. As a rule of thumb in most cases, the harder the steel the more unforgiving and harder it is to bring the blade back, to a razor sharpness.


“There is no such thing as ‘The Best Steel’, only ‘The Right Steel’. Knowing the primary function or use for the knife will help in determining the optimal steel to use for its blade.” :thumbup:

Article continued below....

 

[KennethW]

By kennethw


The Chart Explained:

420/420J2
At the lowest end of the spectrum on the far left and by far the cheapest steel in the range, we have the 420/420J2 steels. These are typically used in low cost China made knives or display knives and swords. Practical use of these blade steels is generally not recommended as they are very soft, very weak and not very wear resistant. They lose their edge really quickly from use. They are however, very corrosive resistant and sharpen like butter, which makes them good as disposable knives, and IMO is one of the better candidates to use in wet or corrosive environments. "Cheap and nasty, I have display knives with this steel, but no working blades. Rust on these blades are deep orange, ugly, and impossible to remove." :thumbdn:

x55CrMo14
This steel is used almost exclusively by Victorinox in most of their knife blades. It’s a tad harder, stronger, more wear resistant than and as corrosive resistant as the 420/420J2. It has a max Cr of 15% and can be polished to a mirror finish. It also has a 0.15% Vanadium which gives it a slightly better edge retention. "Dont know, but my Swiss army knives cant hold an edge even if my life depended on it."

420HC/425M
The 420HC is probably my favorite of the 420 family. It is superior to 420J2 in almost every aspect, and is extremely good in terms of the cost to value ratio. It’s much harder, stronger, tougher, more wear resistant than and even more corrosive resistant than the 420/420J2. IMO is one of the most corrosive resistant stainless steel available today, albeit not as good as H-1. It has slightly less carbon than x55CrMo14, but has slightly more Vanadium which lets it keep its edge almost as well as the x55CrMo14. It is probably the most common steel on low end production knives available today. "Price vs Performance, this steel is unmatched!."

440A/AUS-6
440A blades have had a bad rep historically due to cheap China knives labelling 440 on their blades. I would put this steel on par with 420HC and AUS-6. It is a little more wear resistant than 420HC, but is nowhere near as tough, as hard or as corrosive resistant. Many manufacturers used 440A before switching over to 420HC, which IMO is the better steel. "I dont have any blades with this steel."

8Cr13Mov
This steel is made in China. It's very cheap and easy to use. It has similar properties to AUS-8, but doesnt perform as well. IMO, its somewhere in the middle of AUS-8 and AUS-6, in terms of quality. It's a reasonable steel for its price.
440B/AUS-8
440B and AUS-8 steels are comparable. 440B is very rare and is almost identical to 440A except for the 0.15% extra carbon, which gives it just a tad bit more strength and hardness. On the chart both 440A and 440B are equal; this is due to a rounding error, my apologies. "I don't have any blades with this steel."

440C/AUS-10
Similarly with the previous 2 steels, 440C is comparable to AUS-10. It has almost double to the carbon content of 440A. It is much harder and more wear resistant than any or the steels previously mentioned, and can also hold an edge much longer when used. However, 440C also has its drawbacks. It’s not as tough as the other 440’s and 420HC steels, and not as corrosive resistant. 440C was considered a ‘Super-Steel’ for a long time by some before the emergence of higher end stainless steels. "Have many of old folders with this steel, IMO its the best cheap steel." :thumbup:

H-1
Not to be confused with the H-series of tool steels. This is a specialists steel which excels at corrosion resistance. H-1 is probably the only steel here which is 99.99% rust resistant.
"Perfect for divers or people who constantly work in a wet environment."[/B]

CPM440V/S60V
440V or S60V is a very strange steel IMO. It works of the 440C formula but raises the carbon content to 2.15%and Vanadium to 5.5%. It has insane wear resistance for a stainless steel, one of best of all stainless steels IMO, but can be as soft as 420 steels to get an adequate toughness. A thicker blade geometry would be best to see this steel excel. "I don't really use this steel much, even pressing a screwdriver on the blade will put a pretty huge dent in it , but my Mantis Pit Boss does look pretty wicked."

154CM/ATS34
154CM and its Japanese counterpart the ATS34 are almost identical. 154CM is harder, and tougher than any of the previously mentioned steels, and holds it edge extremely well, albeit not as well as the 440V/S60V. It is possibly the entry level steel for higher end knives. Almost every Emerson knife uses 154CM. "Best overall value for money steel, nuff said."

VG-10
VG-10 is a high end stainless steel, and quite expensive, but cheaper than 154CM/ATS34. Unlike any other steel discussed here, it uses Cobalt in its formula which makes its substrate stronger. IMO, VG-10 has the sharpest edge of any stainless steel. It’s tougher and more rust resistant than 154CM. Many Spyderco knives use VG-10. "I absolutely love this steel, and its the main reason why my left arm is hairless."

CPM154
Identical to 154CM in terms of composition, but undergoes a different process. The CPM version has more evenly distributed carbides and a finer grain structure, with fewer weak spots. Given the choice of CPM154 or 154CM, go for CPM154. "Improved 154CM, no complaints!."

D-2
I've decided to include this into the chart, even though it borders on being stainless. The minimum level of chromium for stainless steels is 13% and D-2 has 12%. This makes it almost a stainless steel, but not really. That a side, D-2 is an excellent steel. It is much tougher than premium stainless steels like 154CM, and has greater wear resistance, but has not much rust resistance when compared to the stainless steels. "A great hard tool steel, with brute force."

CPMS30V
Considered a Super-Steel by many, IMO the best performing stainless steel for my EDC (Spyderco Native S30V, what a beauty! ). Almost A-2 class toughness and almost S90V wear resistance, hardened to 58-61 Rc. Similarly with the CPM154, the CPM process gives it a very fine grain micro-structure, and very evenly distributed Vanadium Carbides, allowing for a more consistent stainless steel that holds an edge like no other. "However, sharpening this blade can be a b!@tch. If you want toner triceps, CPMS30V is the way to go."

CPM420V/S90V
At the pinnacle of steels when it comes to wear resistance. S90V however, is fairly expensive, and harder to obtain than other steels. It holds its edge extremely well.
"If you want a steel which is second to none in terms of wear resistance, look no further."

ZDP-189/Cowry-X
ZDP-189 is a very exotic steel, and only premium knife makers use this steel. ZDP-189 can get very hard, harder and tougher than S30V. Some speculate that it chips when used where S30V does not. It’s much more expensive than S30V, but is less rust resistant. If you like exotic steels and have no budget constraints, ZDP-189 will not disappoint. It will hold an edge much longer than even S30V. “If you think S30V is a b!@tch to sharpen, you aint seen nothin yet.”


More Steels: (more may be included into the chart in future)


CTS-XHP
More on this steel later…

9Cr18MoV
More on this steel later…

CPM S35VN
More on this steel later…

ELMAX
More on this steel later…

M390
More on this steel later…

By kennethw


References:
http://en.wikipedia.org/wiki/Stainless_steel
http://en.wikipedia.org/wiki/Crucible_steel
http://en.wikipedia.org/wiki/Alloy_steel
http://en.wikipedia.org/wiki/SAE_steel_grades
http://en.wikipedia.org/wiki/Carbon_steel
http://en.wikipedia.org/wiki/Steel
http://www.machinist-materials.com/stainless_table.htm
http://www.spyderco.com/forums/showthread.php?t=47155
http://www.leatherman.com/products/faq.asp?c=2
http://www.emersonknives.com/ekEK_FAQ.php
http://mantisknives.com/faqs.html
http://www.spyderco.com/edge-u-cation/steel.php
http://www.swissarmy.com/CustomerService/FAQs/Pages/pocket tools.aspx?
http://www.gerberuk.com/index.php/faq/cat_id/5
http://www.ausknives.com/
http://www.coldsteel.com/faqs.html#Made
http://zknives.com/knives/articles/knifesteelfaq.shtml
http://www.unitedcutlery.com/United.aspx
http://www.latrobesteel.com/assets/documents/datasheets/LSS_420_HC.pdf
http://www.survivaltopics.com/forums/knives-blades/5052-info-steel-quality-in-victorinox-knives.html
http://willamette.edu/~jgates/steelfaq.html
http://www.knivestown.com/ktown/blade_steels.asp
http://faq.customtacticals.com/steels/
http://bit.ly/lv4yeF
http://www.spyderco.com/edge-u-cation/steel.php
http://www.spyderco.com/edge-u-cation/index.php?item=3
http://www.foodieforums.com/vbullet...59-Hitachi-Steel-Spec-Sheet-(AS-ZDP-189-etc.)
http://www.simplytoolsteel.com/stainless-steel-comparison-chart.html
http://www.bladeforums.com/forums/showthread.php/368828-Steel-FAQ


-KennethW

 

[RokBoks]

uhhh cant see the chart

 

[KennethW]

Sorry, re-uploaded using imageshack. original hosting may have been inaccessible from the US.

Thanks RokBoks.

 

[brets-ftw]

very cool though i think your lacking a lot of common place steels that are used in the industry these days

 

[neuron]

Interesting chart. A few quick comments/questions.

1. Are the data based on tests you've conducted yourself, or on information compiled from steelmakers' product data sheets?

2. I find it rather odd that you have "Max Rockwell Hardness" as one of the three properties -- before the image was working, I was expecting toughness to the third property. At least for cutlery purposes, maximum attainable hardness is really only of interest insofar as it correlates positively with wear resistance, which of course is already incorporated into the rating as its own separate component. So I'm not really sure what useful information having hardness as its own separate component of the rating is contributing. To the extent that it positively correlates with a property of interest to knife users (wear resistance) it's already present in the rating, and beyond that it may only be adding noise to the rating.

3. Even assuming that you replaced hardness with toughness as the third component of the rating, the use of this sort of chart would still be somewhat limited since it presupposes (from what I can tell) that all three of the properties -- corrosion resistance, wear resistance, and toughness -- are weighted equally. But of course which of these properties is given greatest weight will vary significantly depending on the intended use of the knife, the location/environment in which it's being used (e.g., humid/rainy versus arid/dry), and numerous other factors.

4. Finally, I think that, in future versions, it would be helpful if you had a more informative way of incorporating the price information. Right now, all you have is a rank-ordering without any values attached, which depending on the precise values and how they're clustered, can make small differences in price seem large, or vice versa.

 

[Sami P]

An informative chart indeed. Saved and thanks for your time.

 

[The Mastiff]

Interesting chart. It doesn't have the 3rd attribute commonly used which is toughness. I don't get the hardness measurement. Price I do find interesting.

I also would have to wonder why Aus 6, and aus 8 perform and image each other in all respects. They are definitely not the same in wear resistance or corrosion resistance. Still, interesting chart.

 

[knarfeng]

As an engineer, I find the chart a gross oversimplification and rather worthless.

Stacked charts suck for making comparisons.

Based on whose data?
I cannot imagine anyone having access to enough data to generate a valid chart covering the factors you have chosen.

Based on what factors? Was the "cost" based on Raw cost of the steel, or did it factor in the varying difficulties in machining and heat treating, which also add to final cost. Did you factor in purchasing quantity? The more you buy, the lower the cost.

Whose Max Rockwell did you take? Different blade makers may set different targets for hardness of the same alloy depending on what final properties they are optimizing.

Every steel type will vary in quality depending on the manufacturer despite using similar steels.

Nonsense. The alloy is the alloy. It's "quality" is unchanged no matter who heat treats it. "Quality" is a measure of how well the alloy meets its spec. So, whose spec are you referencing as a standard?

 

[marcinek]

As an engineer, I find the chart a gross oversimplification and rather worthless.

I strongly disagree. I find it utter nonsense.

Lets ignore for a second that we have no idea where any of these numbers came from or how they were determined.

The graph says 420 J2 has a corrosion resistance around 2.5, edge holding around 1, and max rockwell hardness around 1.5. What does that mean?!? Is there a scale of measurement of rust resistance with a "1" on it?

It's like saying San Diego is a 7 because it has a temperature of 3, and an average per capita income of 4.

Meaningless.

Maybe if you clear up what these numbers are supposed to mean, we can begin looking at if the numbers were arrived at in a scientific manner.

 

[neuron]

As an engineer, I find the chart a gross oversimplification and rather worthless.

I strongly disagree. I find it utter nonsense.

Heh...I tried to sugarcoat it and be at least somewhat constructive in my reply, but I have to confess this is exactly what I was thinking too.

 

[marcinek]

Heh...I tried to sugarcoat it and be at least somewhat constructive in my reply, but I have to confess this was exactly what I was thinking too.

It is an impeccably executed bar graph, and I do admire/appreciate the effort and work involved in creating it. But I think all that sugarcoating it does is lower the credibility of BF.

No doubt Kenneth is a great guy and I'm sure everyone is glad to have him as a fellow BF member (I know I am). But it's just bad science. It's the 500 pound gorilla in the room.

 

[neuron]

It is an impeccably executed bar graph, and I do admire/appreciate the effort and work involved in creating it. But I think all that sugarcoating it does is lower the credibility of BF.

No doubt Kenneth is a great guy and I'm sure everyone is glad to have him as a fellow BF member (I know I am). But it's just bad science. It's the 500 pound gorilla in the room.

Yeah, I agree completely.

 

[KennethW]

Apologies for the oversimplification of this chart. This is my first post.

This chart was initially designed for a friend who had asked me "What is the difference between knife blades, and which should he get, and how much to spend?" As he had gone through numerous sites not being able to find and compare different knife blade steels side by side.

It was by no means an absolute definitive guide, nor was it intended to be so. It was just a guide for him to buy a new knife. Simple as that.

Initially, I had thought to include toughness as well, but thought that a quadrupedal stacked graph looked a little messy. in hindsight, I do agree that toughness would be more relevant than hardness. All info displayed in the graph is not based on my own testing, but a compilation of a few steel manufacturer sites, and a few knife sites.

In future, I will definitely include more details and scientific references to ensure the data is as sound as possible to avoid flaming.

Again, thanks for the constructive feedback, and apologies for the ambiguity.

 

[marcinek]

In future, I will definitely include more details and scientific references to ensure the data is as sound as possible to avoid flaming.

No one is "flaming" you. We are pointing out that your graph makes no sense and doesn't appear to be grounded in anything like science.

Discounting nonsense mumbo-jumbo is not a "flame war."

 

[Revolverrodger]

It's a nice graph... but very subjective and not very objective. To be objective you need references to the original data.

 

[ono724]

As an engineer, I find the chart a gross oversimplification and rather worthless.

Stacked charts suck for making comparisons.

Based on whose data?
I cannot imagine anyone having access to enough data to generate a valid chart covering the factors you have chosen.

Based on what factors? Was the "cost" based on Raw cost of the steel, or did it factor in the varying difficulties in machining and heat treating, which also add to final cost. Did you factor in purchasing quantity? The more you buy, the lower the cost.

Whose Max Rockwell did you take? Different blade makers may set different targets for hardness of the same alloy depending on what final properties they are optimizing.


Nonsense. The alloy is the alloy. It's "quality" is unchanged no matter who heat treats it. "Quality" is a measure of how well the alloy meets its spec. So, whose spec are you referencing as a standard?

So, since you're an engineer, how about you create a steel chart, that uses meaningful data, and that isn't a "gross oversimplification" I think that would be an excellent idea, don't you?

 

[Gator97]

So, since you're an engineer, how about you create a steel chart, that uses meaningful data, and that isn't a "gross oversimplification" I think that would be an excellent idea, don't you?

It is not doable, because the chart deals with the data that is not quantifiable. Therefore, any chart will be oversimplification of some magnitude, or biased or whatever else.
I don't quite understand what is the index of corrosion resistance, is it on the scale from 1 to 10? What is 10? Depending on HT that might vary for a given alloy.
Edge holding translation into numbers like that... Also highly questionable. CATRA machines cost thousands of dollars and still, their data can produce numbers only for very specific type of cutting, which doesn't do much as soon as you add human element into the mix, let alone different types of cutting and chopping.
Max Rockwell hardness seems also off, I have VG-10 and 154CM at 62HRC, but I've never seen CPM S30V at 62HRC, 61 was the max, yet on the chart seems like S30V is harder. Well, at least that criteria can be translated into numbers easily, but doesn't tell the whole story. Just look at the discussions here, there's plenty of 154CM vs. S30V and similar threads, there is no consensus...

 

[BITEME]

It seems to me that a steel chart would have a of a lot more variables,even any of those steels cited you could do a whole series of charts of each particular steel at different rockwell values,then at different blade geometries,then at different thicknesses and so on.I don't understand how any of these steels listed are getting a number? where is this coming from????

 

[Buck_110]

I cannot imagine anyone having access to enough data to generate a valid chart covering the factors you have chosen.

So, since you're an engineer, how about you create a steel chart, that uses meaningful data, and that isn't a "gross oversimplification" I think that would be an excellent idea, don't you?

My bet is it'll go over your head if he did; just like his statement you chose to ignore.

knarfeng is not just any engineer. He contributed to the development of the SR-71 Blackbird(the plane pictured in his avatar). He does know a thing or two about metals.