Optimal edge type for self defence applications?

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Mar 4, 1999
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Given that a knife employed purely for self defence could come across leather, cloth (synthetic and natural), hair, skin, bone, teeth, metal (zips, etc.), plastic (zips, buttons)...

What do you think is the best all around plain edge finish (grabby coarse finish or fine razor finish) for this purpose, and why?

And how does blade profile (hawkbill, trailing point, recurve, etc.) affect this choice?

How does a serrated edge (eg. spyderedge) compare?

What can happen in a real fight, that might highlight the relative merits of each type of edge?

Please be as specific and opinionated as possible, regardless of whether you're basing your answer on experience or conjecture.

Thanks for you opinions.

Dom
 
If you have time to avoid using a knife for defense you should try other means. If you are attacked you are likely to be rushed and put into an awkward posture. You may not be able to make a optimal thrust or slash. You also may only be able to get in one cut. For these reasons I go for an extremely sharp thin edge. This cuts through leather well. I also leave the edge micro-serrated by finishing with a medium-fine diamond hone. This works well with leather. In some cases I will use a file to sharpen the edge of a comparitively soft carbon steel knife or bayonet. This really zips through leather and clothing.

I like a blade that has a lot of belly. This slashes optimally and is less inclined to snag. I don't go for hawkbill or flat blades. I usually avoid serrations due to concerns of snagging. I like serpentine blades like some old switchblades and german sailors daggers. These leave nasty wounds and cut well.
 
I once read a reply to a post like this one stating that the best self-defense knife is a cheap one you wouldn't mind throwing away. The point was that in liberal jurisdictions (also where most of the crime is and where one is most likely to be attacked), the district attorney and lawyers are likely to try to make the person who acted in self-defense into the criminal. So, you should carry a knife you won't mind throwing in the nearest river should you ever have to use it in self-defense, and if you are able to escape from the scene before the cops arrive.

Well, I guess I have gotten off the subject of edges, but cheap knives usually come with hollow ground blades, and those can be gotten very sharp, so maybe throw-away knives also have the best edges for self-defense!
 
Little Claw,

Should - God forbid - you ever have to defend yourself with a knife, remember an old maxim: flight = guilt.

If you cut an assailant, no matter how legitimately you have acted, the fact that you ran away and discarded the knife will weigh heavily against you.

Also, even if you throw the knife away, modern advances in forensics can & will link it to you. You think you've wiped off every trace of every fingerprint? Think again. One hair, one drop of blood or spit, one fleck of dandruff trapped in the innards of the knife will identify you via your DNA.

Don't think you fled past a surveillance camera? Think again.

Honesty is the best and only policy.

maximus "28 year LEO" otter
 
Hopefully you'll receive a reply from Brownie, who instructs law enforcement personnel in the use of knives for self-defense.

All I have to say on the matter is that there are so many variables involved in attacks and armed encounters, it's unlikely that any given equipment and/or specific tactic is going to prove to be anywhere near optimal in a particular situation. General preparedness, being alert and observant, overall martial skills and physical ability, and your ability to think on your feet are critical factors in surviving an attack.
 
Maximus might be right in stating that one has a slim chance of getting away, but I certainly don't think honesty is the best policy in dealing with leftists who believe that the very act of self-defense = guilt. If Bernard Getz or any of the many people in this country who have been prosecuted and sued for legitimate acts of self-defense, had managed to illude capture, then it would have been a far more just outcome than what happened to them.
 
W.T. and Maximus:

Thank you both for your respective perspectives. Both are valuable to me. Maximus, please rest assured that I do not intend to go tooled up anytime soon! W.T., should I find myself in such an awful position, your words will get due consideration.

I have a background in martial arts and choose to go unarmed because that is the law here.

Should I ever choose to go armed, I would prefer something other than a knife, such as a stick or collapsible baton. Ironically, a knife is more likely to be justifiable in a day to day carry sense, so that may end up being the weapon of choice.

I have not given serious consideration to knife fighting until I decided to research it to inform my martial arts (we learn defense against knives, but I am aware that real attacks are somewhat more complex and unpredictable than we simulate). It occurs to me that any such skill is potentially valuable, and it pays to be prepared, not only in terms of skill, but also of equipment.

So my question is purely technical. If I choose to apply a disabling cut to the tendons in the arm, rather than a lethal thrust to the torso or neck, I want to be as certain as possible that my (restrained) action will be successful, regardless of what my assailant is wearing. I've had plenty of practical experience of sharp blades not 'cutting it', so I am interested in what experience/consensus has accumulated here.

Jeff's answer is the sort of argument I was looking for (I hadn't considered edge acuity/thickness), and I'm sure there are other opinions out there, too. Thanks Jeff.
 
In case the eye rolling Mr. Mayo doesn't realize there is a problem with people being arrested in cases of legitimate self-defense, I recommend reading page 20 of the Sept. 2003 issue of the NRA magazine, America's 1st Freedom. There is a story about Ronald Dixon of New York, who shot an intruder in the bedroom of his infant son, and was arrested for using an unregistered gun. The charge was later reduced to disorderly conduct, but this is still unjust in a case of legitimate self-defense.

The real criminal in this case is not Ronald Dixon, but New York DA Charles Hynes who has abused his power by trying to get around Dixon's legal right to self-defense, and charged Dixon with an unconstitutional gun control violation and disorderly conduct. When such officials pervert the criminal justice system for political reasons, then the public can be excused for some degree of civil disobedience.

Sorry, Little Claw, for getting off the technical subject of your question. It is hard to discuss the issue of self-defense without the political and legal aspects coming to mind.
 
Any sharp knife will do in a knife fight. My guess a serrated edge is the best. An experienced knife fighter will first try to stay away from the attackers knife as well as try to disarm him by slashing the arms or wrist. A serrated edge will pierce the clothing first thus enabling the cut, but this would be more difficult with a plain edge.

As a student of forensic science, i agree that it is virtually impossible to wipe away all traces of yourself on your weapon. Most probably it will be linked to you. I have no idea how the law goes in the US but i guess it will be 50/50. From what i've heard a lawyer can win just about any case there.

But in a case like this you've got one good defense. Science never lies. So it's not really wise to throw away your weapon which will actually make you look more guilty. They'll probably be able to check the cuts and stuff and determine whether it was really self defense or not.

A knife in the back is not self defense. heehhe
 
In a knife fight, there are two finishers...........


Last




and next to last.................. :(
 
I prefer a serrated blade. I live in a temperate climate where I am not usually concerned with the blade handing up in heavy clothing and I know from personal experience that it hurts a heck of a lot more to be cut with a serrated blade than with a very sharp one. That being said, I stand here with flame proof undies waiting for replys.
 
Ronald Dixon spent a total of three days in jail for shooting someone with an unlicensed gun. If he'd shot the man with a registered firearm he wouldn't have spent a second in jail. It's the same as if the cops had come to his house and found it full of crack. It was something that was completely unrelated to his shooting the intruder, even though it was about the gun he used.

I assume that if I was carrying around a 10" bowie knife here in Texas and stabbed someone that was trying to kill me I would in fact be brought up on some kind of weapons charges completely unrelated to the stabbing. Maximum blade length for a fixed blade (I'm unsure of folders, but I think it's it same) is 5.5". Same principle.

Pertaining to the original question...
Bowie knives seem the best style for pure fighting so I assume the same would be true for self defense. There's another post on the forum about knife fighting and it could help answer this question.

*EDIT*
And yeah, it's hard to answer a question like this without looking at the legal aspects. Smaller versions of large blades don't always work too well and while a 10" bowie would be great for seld defense, it's highly illegal in most circumstances. :D
 
Actual testing of serrated [ se ] vs. plain edge [ pe ] knives on clothed dummies has shown that se's will produce more drag as the teeth are pulled through the material than a pe.

This drag reduces the depth of the cut to some extent and requires more force to get into the same depth as a pe thats scary sharp. If you keep your knife sharp, but not scary sharp the se is likely to perform as well as the pe.

If both are sharpened equally, I'll take the pe every day for getting through leather, wool, nylon and dungaree material. Wool sweaters, try your se on an old wool sweater or nylon. The teeth will grab the material well enough to slow the slash down. It is a way of seeing how the se teeth grab material and though to a lesser degree, other materials as well. Go slow and watch the teeth grab the material. In a quick slashing motion, the same thing is happening but is reduced so it's hard to see by the speed of the slash.

To respond to others about Dixon and Geotz. The were adults in posssesion of illegal firearms. If you are breaking the law and defend yourself with an illegal weapon, the ONLY good thing to come of it is that you may have survived the attack/encounter. You will then be charged with your own crime/crimes. People that can't see that need to realize if that were not charged wit ha crime and forgiven because it was a justified shooting/stabbing many would carry illegally and decide they would only use the weapon to defend with [ isn't that what we carry for to begin with? ]. It would send the message to everyone that it was okay to carry illegal items on or about your person as long as you only used it to defend yourself with.
Thats never going to happen so get over it, you break the law carrying an illegal weapoon, you are lucky to survive with it possibly but then you will be charged for your illegal activities as well. Anyone think that is not fair? The DA did his job, anything less than charging Dixon would be to ignoring his responsibility to us all and his job dictates.

As to blade shape for defensive purposes. It really comes down to what you will be happy with and carry with you daily. Many forms of blade types means that everyone likes something different.

My personal preference for personal defense is to carry a clip point/modified clip point like the MT Socom or Endura type blade. I like pointy tips that are very sharp which lends to better stabbing.
I also like the true clip point Chinook designed by my instructor JAK.

I am also enamored with the karambit type of blade lately but people should keep in mind there are specific moves/techniques required for it which are somewhat different than your normal EDC.

Leaving the area will get you a guilty verdict if caught, hard to say you were right when you "dedemow" [ unass ] out of the area after the fact. Too big a risk for most to take and unnecessary if the self defense is good [ and you can articulate reasonably why you did what you did to defend yourself ]. Not good advice at the least of it.

I also would suggest a serious defensive knife be made from the best steel you can afford and not the 440/china cutlery stuff thats out there. Throwaways? Why, if I'm thinking about throwing the knife away after I use it, that might go to mindset before the fact with a DA and jury if they were to find out. I'm not about to trust my life to junk in the off chance I might get to throw it away after the fact in lieu of facing the aftermath of a self defense situation.

Thats like saying I should own a junk car that barely runs because if I get into an accident I won't feel so bad when I have to buy another.
On the contrary, I would suggest you look at as many different knife designs and knives as you can. Handle them all and one or more will "whisper" to your hand. Close your eyes and let your hand "feel" the knife. It will tell you if it likes it and has enough ergonomics for your build/handsize.

If carried for defensive needs, the knife needs to be quick to get into play from the pockets. Some models lend themselves better to this aspect and my own preference for pure speed of presentation is tip down on a good linerlock, though I'm always aware of the linerlocks fragility in possible release of the lock during strenuous/heavy duty work. Something to be watchful for.

I had stopped carying linerlocks for awhile lately and went to lockbacks designs which are for the most part stronger and less prone to accidental release of the lock under extreme circumstances. I'm back today with carrying the MT Socom, one of my all time favorites along with the Military model from Sypderco. Very fast at presentation and ready for action as soon as I touch it on the pocket.

Good luck in your quest. Try many in the hand if you can, then you'll get a "feel" for what you like. Let the hand dictate what it likes, you'll be better off in the long run than just getting something becuase you like the looks.

Where defense of my person is at stake, no compromises in steel, overall fit and finish, ergonomics, dependability can be allowed. If I lose a 400.00 custom in defense of my person and it performs as I expected it to and saved my bacon, I'd be happy to go out and buy another one after all was said and done.

Brownie
 
It would send the message to everyone that it was okay to carry illegal items on or about your person as long as you only used it to defend yourself with.

I refer you to the second amendment of the US Constitution. Carrying weapons for self-defense is not supposed to be illegal.
 
Originally posted by Point44
My guess a serrated edge is the best. A serrated edge will pierce the clothing first thus enabling the cut, but this would be more difficult with a plain edge.


As Brownie indicates, a serrated edge tends to "bog down" when piercing heavy and/or fibrous material such as denim, or multiple layers of material (ie, denim jacket over cotton T-shirt, etc).

A plain edge is preferable when piercing clothing.
 
W.T. Beck:

Theres a difference between what is and what is "supposed" to be. I'm not sure the courts would take that comment with much consideration for your breaking the law by carrying illegally.

Carrying waepons is not illegal, only certain restricted items within the "dangerous weapons" statutes are illegal. Pick a weapon thats not illegal to use [ and get some training in that weapon system ] if you plan on defending yourself and not be charged with unlawful possession of a restricted weapon after the fact.

Both Geotz and Dixon knew they had illegal weapons and took the chance in carryiong them that they may get caught. To understand your thinking on this we would have to conclude that it is okay to carry illegally as long as the end justifies the means [ which is not the case where dangerous weapons is concerned ]. Every gang banger in jail could make a case for carrying illegally so he could protect himself from rival gangs [ ya right ].

Brownie
 
brownie

Thanks for your reply. What is you opinion on the best finish for a PE. i.e. a fine razor-like (mirror) polish, or a coarse, grabby (micro serrated) edge?

Black Mariah

Due to legality (or lack thereof) of carriying any weapon for SD here, effective, comfortable, long term concealment is a proirity, so I would most likely be looking for a folder or FB with a 3-5" blade, hence my interest in getting optimum cutting from what edge I have available. If the sh*t really hits the fan, I'd probably go with my butterfly swords, and edge finish be damned! :D

kamkazmoto

I hadn't considered the importance of climate to this question very thoroughly. Thanks for your observation.

If clothing were much less of a factor, would a serrated edge become favourable for these reasons? Should I therefore carry a scary sharp PE Endura in winter and a SE in summer?

If you were going to carry a Navigator (2") for absolute last ditch "get your knee off my neck" kind of action would you be thinking PE or SE?

Guys (and gals?), feel free to keep discussing the political arguments here, they are interesting and useful, and there are some that I have not considered or discussed before. I also look forward to more elucidation on the edge question.

Thanks all,

Dom
 
Little claw:

I like PE in all my defensive knives no matter the size. If they are kept scary sharp they will outperform the SE most everytime. My EDC's are never used for anything but reserved for defensive work only so they stay razor blade sharp.

I had always condsidered a smooth mirror polished razor edge the optimum and in most cases still carry them that way. Lately I have been putting a toothier edge on certain models like the Chinook I recently obtained.

My MT Socom sits in the RFP with a mirror polished scary edge as the primary defensive blade today. Yet, if I were to put the Chinook in my pocket I'd have the toothier edge on the edc that day as well.

Clothing? I like the mirror edge scary sharp blades, less drag [ no teeth ]types of edges, they seem to be able to seperate the materials and not slow down much, if at all, when drawn across clothing.

For general utility, I like the toothier edges, they seem to "bite" more into the material like cardboard and rope.

Paper? I would go with mirror edge so the paper is not "torn" but seperated as it is cut like a razor blade.

Both edges have their advantages in certain arenas. I think it's personal preference but I do like the mirror edge for defensive work myself, though others mileage and experience may vary.

My wife has become enamored with the new Blade-tech "mouse2" I received from Tim Wegner a few weeks ago. That blade is real small, the overall package is small but that PE razor edge cuts through about anything she finds a use for like cutting plants in the garden, cutting twine on bails of hay, plastic twist ties, fiberglass strapping, etc.

It has been very difficult getting her to carry any folder on a full time basis, but she has carried it since I received it after looking it over. The only problem I see with it is NOW I WANT IT BACK. It's gotta be the sweetest, most user friendly small knife I have ever seen. Gonnaa have to get Tim to send another one my way, I plan on taking the clip off it and just carry it in one of the pockets.

Good luck in your quest.

Brownie
 
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