How to Determine the Blade Performance of a Tactical Knife?

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Well, the first thing in my opinion to consider when determining the performance of a tactical knife or tactical blade is will the steel that is used by the manufacturer or custom maker be able to withstand stress well? Will it take the stress of the environment you subject it to and the chores you demand from it? Will you get the cutting performance that you want?

So, one needs to consider a number of factors when, say, one is looking for the best bang for their buck in a knife, folding or fixed. This article Best Tactical Folding Knife provides detailed insight into just such a selection process.

The Angle

If a knife’s edge has an angle or profile that is too thick you might lose cutting performance over the “long term” or if the steel hardness is not “hard enough” for the tasks you perform then you take a hit in blade strength and possible wear resistance. Of course on the other side of the coin if a blade has a thinner profile and a harder Rockwell Hardness (RC) rating this will of course raise the bar on cutting performance.

Determining what the tactical knife will be used for is of course integral to the decision process. In reality, generally, we all use knives for pretty much the same thing and if you are going to test those limits or use it for a purpose it was never intended to fulfill, well the results, whatever they are, will be well earned. That said the standard measures still apply – edge retention, wear resistance, profile, sharpening ability, grip, easy of use and portability.

As has been noted before in other related Prepper Journal articles, the base material is steel and this little guide as to the components of steel will help you make a better choice.

As a collector tactical knives, I consider the following when deciding what to carry and how to use my tactical knives in my daily life. Wear resistance, toughness, edge holding ability, sharpen ability, general overall strength, and of course stain resistant qualities Let’s look at some of the aspects that one would look for in a tactical knife steel.

Wear Resistance

No other way to say it except that this is the ability of the tactical blade steel to withstand wear, be scratch resistance and not becoming “malformed” from hard use. The main focus here is on durability of steel, the way the carbides of the steel are allocated within the blade steel of choice.

  

Blade Strength

Tactical knife blade strength is determined by how much punishment the overall knife can take as well as how much the blade can take before it becomes deformed. This is important in certain cutting chores and strength goes hand in hand with its brother hardness. The fact of the matter is that the harder tactical blade steel is the longer it will stay sharp and resist becoming deformed.

Steel Toughness

The toughness of the steel is the ability of the steel to take an impact without suffering any major damage. I am referring to things like the steel chipping or cracking under the stress of an impact. Will the blade steel chip or crack from being used in certain chores like chopping? Was the knife intended for this type of chopping chores in the first place? Doubtful, though it may have been a consideration and part of the quality assurance testing. When it comes to deciding what steel you want to use for a tactical knife, this will make or break most manufacturers.

The big decision is strength versus toughness. Many people think this means the same thing but it does not. Tensile strength vs fracture toughness is the reality:

Tensile strength is a measure of the maximum stress that a metal can support before starting to fracture. Fracture toughness is a measure of the energy required to fracture a material that contains a crack. As the yield strength increases, the amount of stress a metal can support without deforming increases.

Kinda complicated. So blade manufactures, like anyone working with steel in their product development process, have to consider the physics of the steel they use, based on the “designed purpose” of the product, the projected misuses that will have an adverse affect on the product while, as with EVERYTHING, factoring in costs. And you just wanted to know the name of a knife and where to but it 😉

Steels Stain Resistance

This is of course the ability of the chosen steel to resist rust and oxidation, in other words the steels corrosion resistance. Can the tactical knife steel handle a salt water environment like Spyderco’s new Salt-2 folder knife in which the carbon, the standard hardening ingredient in steel, has been removed and nitrogen has been put in its place giving this particular steel superior performance against rust.

  

Does the steel that a manufacturer or maker has chosen have stain resistance resistance to things that are acidic like lemons, or other citrus fruits, or the blistering agents in say an Agave plant (tequila in its original form is a powerful blistering agent)? Additionally things like oxidation and pitting can affect  edge loss on the very primary edge of the tactical blade, that part that makes contact with that which you want to cut.

Edge Holding Abilities

This is of course how well the chosen tactical knife blade steel holds an edge. While there are many people out there that have a decent knowledge of tactical knives, there is a common misconception that wear resistance and edge retention abilities are the same thing.

They are not! The ability of blade steel to hold or retain an edge is job/chore specific. If blade steel can hold an edge, then it can resist wear to a certain point. The fact of the matter is that different chores or cutting duties will require different edge angles and grinds as well as different edge retention properties. Isn’t this all so simple?

There are some other things to consider when learning about the properties of steel and steel performance and they are things like the steels ability to take a tactical knife edge. Let’s face it; some steels just take a better edge than other steels. They will sharpen keener.

A fine carbide structure will produce a finer/keener edge, while steel that has a coarser carbide structure at the primary edge may not sharpen so keen. Another thing to consider when picking steel is how the steel is produced. Steel that has impurities will not perform as well as steel that manufactured to demanding standards. Is the edge of the steel toothy enough?

I like D2 steel for a toothy edge on my tactical knives. It goes back to the carbide structure of the edge, the mini serrations that you can see if you can magnify a tactical knife edge enough. The carbide structure will denote the toothy nature of the edge.

So here comes the eternal question again: What is the best tactical knife blade steel? I truly do not believe any such animal exists because there is steel for every job. Some of them are good and some of them are bad. If we stick with good quality steel there are still many choices, and generalization is just a scapegoat -“stainless steel is better than carbon steel.”

I just do not follow that kind of reasoning and that is because you have to consider what kind of work the intended steel is going to be used for. So the best thing I can suggest for tactical knife enthusiasts, collectors and lovers is to learn as much as you can about steel properties and then in time you can decide what the best steel is for you at that time.

I hope you have enjoyed this post!

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4 Comments on "How to Determine the Blade Performance of a Tactical Knife?"

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John
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The problem is, that although the particular steel is of great importance in choosing a knife for a particular purpose, that is not the only factor. It’s not like a maker chooses a steel and just cuts out the blade. There are several manufacturing steps which impact the desirability of the resulting knife. Forged or not, hardening and quenching steps, and general processes will result in two knives which started with the same steel and look the same, being completely different in performance.

Les
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I’m not sure exactly what a “tactical” knife really is. I am of the opinion that application of the word “tactical” is more of a marketing ploy by manufacturers/retailers. Most knives I’ve seen with the tactical title appear a bit Rambo’ish, and may be OK for prying open ammo crates but not so much for the normal daily tasks most of us use a blade for. Steel type is diffidently a factor and of consideration, however. Its impossible to “have your cake and eat it to” when it comes to ease of sharpening AND edge retention unless there is a… Read more »
John
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“The tactical knife is a knife with one or more military features designed for use in extreme situations, which may or may not include a design capability as a fighting or combat weapon. Since World War I, the fighting knife in military service has gradually evolved into a dual-purpose or ‘fighting-utility’ knife, suited for both knife fighting and utility roles. As a consequence, the terms ‘fighting knife’ and ‘tactical knife’ are frequently employed interchangeably.” (Wikipedia) So yes, the term “tactical” is applied anywhere it can conceivably be used in order to encourage people to buy them. Like with “survival” knives,… Read more »
Les
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Dead on.

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