I have written a number of in-depth articles on the topic of blade steels and their relative strengths and weaknesses over the years – from detailing whether or not I think super steels for knives are worth it, to guides on how to sharpen stainless steels, all the way over to common knife myths and why they’re not true (again, many of which are about knife steels).
I think it’s fair to say that I have a lot to say on the matter. However, even with all I’ve already written on the topic, I still do get a number of related questions directed my way. This made me feel that a truly comprehensive guide on the topic of blade steels was warranted; so here’s my attempt – with a basic overview of steel as a whole, a decent (non-exhaustive) list of all the steels I consider to be relevant in the knife community by today’s standards, and an outline of each steel’s place in the market. So let’s start at the very beginning…
Spyderco Sage 2 Titanium Framelock Knife – Amazon
Why Does Knife Steel Matter?
A very good place to start.
While steel in itself is not the only determining factor you’d use when discussing the performance of a knife, it’s certainly important, and arguably has taken front and center stage when it comes to advertising.
Very rarely do manufacturers discuss grinds or heat treat, and yet every year we are flooded with a deluge of the “next greatest super steel” that will completely revolutionize knives as you know them! This is of course absolute baloney because the upgrades in steels are incremental at best, and last year’s “top end steel” truly won’t be significantly (or noticeably) inferior to the current flavor of the month.
At the end of the day, edge geometry, and not blade steel, is the most significant aspect of a knife with regards to real-world impact. A glorified pry bar of a knife will not become a super slicer just because it has a high carbide super steel that is conceived with edge retention in mind, and in the same vein, an anemic filleting knife in CPM-3V will not be optimal as a beater/rough duty blade just because it features a tough steel. Like everything in life, we should try to view things logically and not get swindled and carried away by marketing nonsense. And while yes, it’d be nice to think your recently purchased knife with some newly created super steel meant that you were holding the latest, greatest, very best thing since sliced bread in realm of knives – if you’ve led yourself to believe this and thereby bought into the product hype, you’re unfortunately deluding yourself.
With that said, some steels are better than others, and if you wish to drop big bucks to have the optimal performing blade in terms of matching the blade profile, edge geometry, and blade steel, then certainly there are steels that would be better suited compared to others.
It all depends on what you’re planning on using that steel for. Right tool for the right job? Always true. And in this case, you’re going to be learning which blade steels make for the right tool for your particular right job.
What Makes a Steel? Steel Composition & Properties
First, let’s take a look at the more common elements used to manufacture steel.
It’s important to note that I didn’t list all of the elements of steel composition to the chart below. Nitrogen (used in H1 steel and supposedly in Busse’s INFI steel), for instance, I have not listed. I did not go into length over the elements’ reactions with other elements either, but rather, just focused on an overview so as to help you clearly understand what goes into the making of a steel. Bare this in mind as you take a look!
Blade Steel Compositions
|Carbon (C)||-Increases resistance to wear & hardness
-Improves edge retention & tensile strength
-Single most important hardening element
|Chromium (Cr)||-Imporoves hardness, toughness & tensile strength.
-Significantly improves corrosion resistance.
|Cobalt (Co)||-Enables higher temps when quenching during heat treat.
-Works well with other elements to boost properties in complex steels.
-Increases strength and hardness
|Copper (Cu)||-Increases wear resistance as well as corrosion resistance|
|Manganese (Mn)||-Allows higher levels of hardening.
-Improves wear resistance & tensile strength
|Molybdenum (Mo)||-Improves ease of machining.
-Increases harden-ability, toughness & strength.
|Nickel (Ni)||-Adds corrosion resistance, hardness & strength.|
|Phosphorous (P)||-Increases machinability, hardness and strength.
-In high enough concentration, causes brittleness.
|Silicon (Si)||-Increases tensile & yield strength.|
|Sulphur (S)||-Improves machinability but lowers toughness.|
|Tungsten (W)||-Increases strength, hardness & toughness.|
|Vanadium (V)||-Increases strength, hardness and shock (impact) resistance.
While the above table is a good primer on steel composition, steel foundries have over the years developed new ways to make steel – from powder metallurgy to exotic friction forging. The elemental composition will only tell you so much, and at the end of the day, you will have to go with your own experiences on top of the information floating around the internet when ascertaining the viability of a specific steel for your given purpose, especially considering the ridiculous amount of hype on various forums whenever something new is introduced to the market. Being a cynic is strongly recommended these days.
Kershaw Thermite Everyday Carry Knife – Amazon
How to Choose a Blade Steel
The core attributes you will want to use when categorizing steels are the following;
Edge retention & stability: Ability to hold an acute edge. This is probably the most important metric if you consider a knife’s core purpose to cut. When discussing steels and super steels, the measuring rod is usually based on edge retention. Check out the excellent testing by Jim Ankerson concerning edge retention of the current crop of modern steels at their respective hardness.
Ductility: The ability to flex under load without fracturing. Not necessarily tied with toughness, as a filleting knife needs to have high ductility without needing to be tough.
Toughness: The ability for a steel to absorb impact before fracturing under stress. A good example of a tough steel is S7 tool steel. Note: toughness is not at all the same thing as hardness. In fact, many times the hardest steels are not the toughest, as the hardest steels will fracture under stress much easier than slightly softer steels.
Corrosion Resistance: If you work near salt water or live in a high humidity area (looking at you Florida!) then corrosion resistance will probably matter a great deal to you. Stainless steel is generally considered to be a steel with 13% or more of chromium. As per the name, stainless only means it is resistant to staining (i.e. “stain less” not “stain free”). Stainless steel can still rust under the right conditions. If you are having issues with stainless steel, and want something that’s basically rust proof (not merely stainless), then check out blades made out of H1 steel (example: the Spyderco Salt series knives, like the Pacific Salt) and X15TN (example: this version of the Benchmade Pardue). Blades made out of these steels will be an optimal choice for high humidity areas.
Rockwell Hardness: Some manufacturers chose not to harden steel to optimal levels for edge retention. Some do this due to lack of manufacturing tolerances, others because they prefer to heat treat a knife to the lower end of the hardness scale so that it can handle higher levels rough use and thus do not have to budget for more returns under warranty. Whatever the reason, it’s important to note that CPM S30V from Spyderco (used for the Paramilitary 2) will have marked difference compared to CPM S30V from Kershaw (used for this version of the Kershaw Blur); so don’t go looking at the steel type exclusively without doing your due diligence.
Kershaw Shuffle EDC Folding Knife – Amazon
My Compendium of Steels
Before we get to the nitty gritty, I want to explain my choice to not use numerical values in my tables. I do not wish to use loosely defined metrics such as “7.5 out of 10 edge holding” or any other derivative metric due to the shifts in the steel landscape over time. To use a metric today would mean that in 10 years time, that metric would no longer be accurate, as the ceiling gets pushed higher and higher over time. Consider that 30 years ago, 440C was considered a premium steel!
As a result, here I’ve used metrics (ambiguously) that I think will stand the test of time: the name, general purpose of the steel, and ease of sharpening.
My list is not exhaustive. If you want a digital spread sheet of all steels and their compositions, check out the zknives steel chart!
Concerning edge retention and toughness, for further research you may want to consult charts from credible third party sources, as well as rankings from respected aficionados like Frank R. and Jim Ankerson. You’ll also find the world of performance cutlery interesting if you’re looking for a more exhaustive analysis; if this strikes your fancy, check out the detailed work of Cliff Stamp here and the CATRA testing results here.
And finally, if you want me to add a steel that’s not listed below, please just leave a comment and I will get to it (even if it’s not suggested I will update these tables with more steels as time allows).
Common Stainless Blade Steels
|Steel Name||Type||Ease of Sharpening|
|CPM S90V||High Edge Retention||Very Hard|
|M390||High Edge Retention||Very Hard|
|ZDP-189||High Edge Retention||Very Hard|
|Elmax||General use (Premium)||Hard|
|CTS-XHP||General use (Premium)||Hard|
|CPM S35VN||General use (Mainstream)||Moderate|
|CPM S30V||General use (Mainstream)||Moderate|
|CPM 154||General use (Mainstream)||Moderate|
|154CM||General use (Mainstream)||Moderate|
|ATS-34||General use (Mainstream)||Moderate|
|D2 *Semi-Stainless||General use (Mainstream)||Moderate|
|VG-10||General use (Budget)||Easy|
|H1||Marine use (Rust Proof)||Easy|
|X15TN||Marine use (Rust Proof)||Easy|
|N690||General use (Mainstream)||Easy|
|440C||General use (Budget)||Easy|
|AUS-8||General use (Budget)||Easy|
|CTS-BD1||General use (Budget)||Easy|
|8Cr13MoV||General use (Budget)||Easy|
|14C28N||General use (Budget)||Easy|
|13C26||General use (Budget)||Easy|
|12C27||General use (Budget)||Easy|
|420HC||General use (Budget)||Extremely Easy|
|440A||General use (Budget)||Extremely Easy|
|AUS-6||General use (Budget)||Extremely Easy|
Common Carbon Blade Steels
|Steel Name||Type||Ease of sharpening|
|CPM M4||General use (Premium)||Moderate|
|D2 *Semi-Stainless||General use (Mainstream)||Moderate|
|INFI *Semi-Stainless||Toughness (Premium)||Moderate|
|M2||General Use (Mainstream)||Moderate|
|Carbon V||General use (Mainstream)||Moderate|
|1075||General use (Budget)||Easy|
|1095||General use (mainstream/budget)||Easy|
|W1||General use (Mainstream)||Easy|
|52100||General use (Mainstream)||Easy|
|Super Blue||General use (Premium)||Easy|
Spyderco Paramilitary 2 Folding Knife – Amazon
Blade Steel Misconceptions & Myths
The following are common misconceptions that are spread around the internet and/or that have been submitted as questions from readers. If you have any others please comment so they can be included here!
1. Inox, Rosterfrei, & surgical steel are not the names of steels, but undefined categories that denote a stainless steel. There is no reference for composition or quality (they could be composed of just about anything).
2. As noted previously – hardness does not imply toughness. A hard blade designed for edge retention like a CTS-204P Southard by Spyderco will not be tough in terms of tensile strength. The same thing can be said about a 1075 chopper like the Condor Hudson Bay; it’s tough but definitely not hard.
3. A CPM-S30V blade hardened at 60HRC will handle very differently to a CPM-S30V blade at 57HRC. Check out Ankerson’s steel rankings for real world testing.
4. A better steel won’t necessarily make a better knife. The steel may be the soul of the blade but the ergonomics are the heart. A comfortable knife with good edge geometry will perform better in real world scenarios. Don’t be blinded by marketing gimmicks.
5. A hair whittling sharp edge is dependent on your patience when sharpening. Steel matters up to a point, but more importantly, it should be obvious that the edge stability of a hair whittling sharp knife will be sub par. The edge will deform very quickly should you use it for any kind of real, practical work. Once again – marketing gimmicks are not representative of real world performance. A hair whittling sharp edge can be put on an inexpensive Victorinox Swiss Army knife, but slice a sheet of paper and it will be gone.
6. San Mai & Laminated steels are not types of steels, but rather a process of cladding a steel with a different steel to offer a benefit, whether its corrosion resistance (inner carbon steel core clad with stainless steel) or for strength/toughness benefits like Cold Steel’s San Mai III.
7. Damascus steel is the process of folding or fusing two different steels together. Known for its unique patterns when etched with acid, it is primarily used for aesthetic purposes and not (contrary to popular belief) for performance.
8. Collectors on forums will often dismiss some steels based on perceived inferiority, but realistically speaking, there are no “pot metal” steels used for knives from known manufacturers these days. Technology has advanced significantly enough to make a passable steel knife trivial to mass manufacture. Some may hold an edge better than others but unless your buying a Pakistan garage sale special, all will hold an edge. For a while at least.