Tactical Knives part II

[Overload]

There's an article in one of the knife magazines this month that says that even knives made with the same steel can have different edge keeping characteristics.  It says that even today there's still luck in creating a knife that keeps its edge.

Material hardness is measured on the Rockwell scale.  The higher the number, the harder it is.  However, if it's made too hard, it may become brittle.  The harder a blade is, the longer it will stay sharp.  A harder knife will also be harder to sharpen once it does get dull.  In addition, some materials take an edge better than others.  Cost is also involved in makers choosing what material to use for a blade.

D2 and M2 were designed for high speed tool use.  This means high heat and great wear resistance.
ATS-34 and 154CM are considered the same steel, made by two different manufacturers.
S30V is considered the first steel made specifically for blades.
VG-10 and GIN-1 are the same steel.
S60V and 440V are the same steel.

The newest evolution in steels for knives is powdered steels.  The making of these steels involve putting the powdered ingredients under high pressure until they 'melt' together.  CPM-S30V is the powdered version of S30V.  The powdered process creates a more uniform molecular structure.

[Michael Janich]

With the vast amount of quality "Tactical" knives on the market, I wonder if Mr. Janich might jump in and give us some brief thoughts on the pros/cons of the various types of steel used in manufacturing knives.  Even though I have some knife fighting skills in my toolbox, I'm relatively ignorant when it comes to the properties of the various types of steel. 

Not sure if you would normally touch upon it, but any thoughts on Damascus steel would be appreciated.  Damascus blades sure are beautiful, just not sure if they make good fighting/working blades.

Thanks,
USSA-1

Sorry for the slow response. I've been in Germany for the past week at the IWA (the European equivalent of SHOT) show and have been away from the forums. Thanks for your patience.

This is a question I get a lot. The bottom line is that the performance of different steels can really only be objectively quantified when they are used in knives of identical design. Cutting and puncturing performance are more a matter of blade design and edge geometry that they are steel composition--especially when it comes to defensive knives.

Consider two well-designed, identical knives made from different steels that are properly heat treated to comparable hardnesses. Ergonomically they're the same and their cutting potential (based on edge geometry) starts off exactly the same. If both are tested in exactly the same way, the qualities of the steels will shine through and allow you to quantify things like edge retention, ease of sharpening, etc. Unfortunately, many people get a poorly designed knife made from a particular steel and, when the knife performs poorly, claim that the steel sucks. A lousy design rendered with the latest super steel will still perform poorly, even if the POTENTIAL of that steel is better than that of other materials.

It should also be remembered that the ability to sharpen a knife properly determined how well that knife will cut. I've had many people condemn a particular steel because it didn't perform well. When I hear that, I often ask to see their carry knife. All too often, that knife is not sharpened properly and has no hope of performing well.

Since knife maintenance is a HUGE part of achieving proper performance, I should also address stainless versus carbon/tool steel. Stainless steel is any steel that has a specific amount of chromium in the alloy (by definition, at least 10%, but in cutlery steels typically at least 13%). It helps prevent rust, but does not make a steel completely stain or rust proof. If you live in a humid climate, carry your knife in a leather sheath, carry your knife close to your body, or fail to maintain your knife, it will rust.

Damascus steel, made properly, can be stronger than homogenous steel because its multiple layers give it strength--much like plywood can be stronger than ordinary solid wood. Some folks claim it's also "toothier" and can cut a bit more aggressively than ordinary steel, but I think that's more of a matter of sharpening than the steel properties themselves.

For small knives intended primarily for personal defense, just about any modern cutlery steel is up to the job and will perform well. I have had very good experience with AUS8A, 440C, 154CM, ATS-34, ATS-55, GIN-1, S30V, BG42, VG-10, and even the "alphabet soup" Chinese steels. On the tool steel side, I've also had great experiences with O-1, 1085, 1095, A2, D2, L6 and others. At the same time, I've had some terrible experiences with poorly ground knives made from very high-speed materials.

For long fixed-blade knives, utility knives that will see lots of use between sharpenings, and specialized pieces, steel choice can have a significant impact on a knife's performance. For folding knives--especially those reserved primarily for personal defense--I think the steel issue is overblown and there ought to be more focus on edge geometry and proper sharpening.

I hope this helps.

Stay safe,

Mike

[DonWorsham]

there ought to be more focus on edge geometry and proper sharpening.

So, what is the best way to sharpen a knife? I currently use a tool similar the one in the picture below to sharpen my carry knife. I don't use the knife to cut much,  prefering to use a razor-blade type knife for chores.

[Overload]

Don,
 IMHO, the best bang for the buck is the Spyderco 204 Tri-Angle Sharpmaker.  I like it because it comes with sticks of different grit, and the flat and ends allow a total of 4 stages of sharpening.  I like the angles these sticks are set at, so all you have to do is hold the knife straight down every time.  There are even two different angles usable for profiling and sharpening.  I also like the included DVD that walks you through sharpening knives as well as other edged and pointed items.  All for around $55 street price.

[Ping]

Autos are legal in Tennessee also Hazcat. That is why I try to add to my collection while visiting Gatlinburg. 

[Sponsor]

[Hazcat]

Ping,

I'm looking for a good auto with a 3 inch MAX blade for everyday pocket carry.  A 'utility' knife that I can work with one hand easily.  A half serrated blade would be nice but NOT necessary.

Right now I carry an old (at least 30 years) K Bar with a 2 3/4 inch drop point blade.   LOVE IT but it is hard to open and is getting in need of serious TLC.  If I could send it to someone who would 'do it right' for oh say under 100 I would go for it.