Size Does Not Matter with Thrusting Weapons 

Sending this video to my wife and her boyfriend, thanks Matt!

"Remember guys, 3 inches is magnum." - Garand Thumb 2023

For context: a bullet is a thrusting weapon. We have just delegated the thrusting to a machine.

I suppose that's why spear heads are usually so short.

A 6 minute video is basically a youtube short for Matt

(Size Does Not Matter with Thrusting Weapons) "I challenge you to a duel sir!" *draws rapier.* Me: *pulls out thumb tack* "I accept your challenge"

Matt giving off that small blade energy

The point of length in a thrusting sword isn't more penetration, it's more REACH. You get a long sword so you can stab from a safer distance.

Spinal Tap logic: "My sword is longer so it stabs deeper". -Right, but the human body is still only so thick, so you can only stab it so deeply until you poke through the other side. "But my longer sword stabs deeper than your shorter sword, its longer"

It’s not about penetrating 20 inches, it’s about being able to have a greater reach than your enemy. That is why it is important to have a longer stabbing instrument.

A Fairbairn Sykes is a remarkably beautiful thing.

as my polish uncle who used to teach historical fencing to theatre actors would always tell me "never forget that a scalpel can cut, and can cut better than a kitchen knife or even a sword, its all about how you use the blade that matters, anyone can pick up a blade and swing it around like a stick, but it takes knowledge and patience to cut cleanly and accurately" i took that to heart, practise 2 hours a day with my rapier even though i never have a reason to own one, keep my skills sharp and precise

But a politician told me....

Same conclusion I came up to when studying the kinds of combat knives people carry today. 6inches is right about the sweet spot but a lot of people carry Folding Knives which may be round 4inches. And while its for utility mostly, you can look up a clip of a Navy Seal eviscerating a Ballistic Gel Dummy with a Pocket Knife. If you're in shanking range then plunging a 4 inch or 10 inch blade wont make much of a difference.

That's what I keep telling to my GF !

You are correct Matt. The length of a blade only gives you reach. I've done a bit of reading about Spy's and Spy craft and one thing that's across the board is teaching the spy to use a knife and finding one at any meat market or store. One can get into bunches of trouble buying a gun but no one looks at you twice if you walk home with a chef knife. The last 4 killings here where I live was all done with kitchen knives one of which the victim was completely disemboweled on mass transit. That's here in the US where you can get a gun.

Width and profile, however, can have a significant effect on how serious a wound one can render; Both in terms of penetrating ability, where a narrower blade will likely encounter much less resistance, and so be more likely to puncture resistant clothing, and in terms of the size of the wound channel, where a wider blade can result in more tissue damage and blood loss. And yes, going out through the far side of your target can make for a quicker, more efficient kill, due to blood loss through two wounds rather than one. Ask any hunter, whether they use archery tackle or firearms.

Absolutely correct, nobody in the military involved in actual knife fighting carries huge 80's Rambo knives. Blades around 5 inches are way more used and useful.

Yup. The reason my favorite "bush knife", and the type i used to hang on my webbing in the Army is about 8" has *nothing* to do with it as a weapon. It is 100% so it works better as a *chopper* if i have to take down smallish saplings or split firewood.

The reality of the situation in my experience…what matters is how quickly you can draw it & put the point-(or edge, if you want to just injure to put an assailant into shock)-where you want it to go as effectively as possible.

In Marine boot camp during bayonet training, our instructors "drove the point home" 🙂 that when thrusting with the bayonet, it was only necessary to go about three-inches into your enemies body. Later, while working as a paramedic and a police officer, I understood the anatomical aspects of this length of thrust. You can do a heck of a lot of damage with a three-inch knife, or a simple short thrust with a longer blade.

I would think, though, that a longer blade might offer some benefits in delivering blows from unusual angles. The torso isn't all that deep front to back, but if your thrust is coming from below (say, under the ribcage) or from the side, that extra length would translate into greater tissue disruption and a better chance to reach vital organs. I've tended to see that as part of the point of the longer blades on rondel daggers, for instance.

Thank you for the boost in confidence

William Fairbairn said that after about 6 inches your pretty much stabbing air.

one thing you didnt mention, is even with a 3 inch or shorter blade, you likely still have more than enough reach to kill, because stab wounds, once the blade reaches the wider hilt/grip etc, they *compress* the flesh being stabbed. So, a person may only have a 3 inch blade, but he may be able to make a 4 or 5 inch wound by stabbing hard enough to compress the flesh together.

Sir Richard Francis Burton recommended that a bayonet be used with short "darting" stab so as to not bind up the weapon in an opponent's body.

You managed to persuade me: Let's ban kitchen knives.

True, however it does matter in slashing attacks. That's why people tend to grab the big chef's knife, rather than the smaller paring knife. Bowie knives are big for a reason.

The obverse is also true: I always carry a Victorinox Rambler (with its impressive 3.5cm blade) on my key chain. Naturally I forgot to check it in before a flight, and security was not pleased. I had to do whatever they told me to do while asking myself "do they expect me to slowly carve someone to death?"

There are some who assert the original knife used by Jim Bowie may have been a butcher's knife. Knives specifically designed for combat tend to be poor utility knives, too small, too narrow, generally unsuited to any purpose other than fighting. The US Kabar type knives were purposely designed to be useful, rather than as single purpose tools that would rarely be used. The Mark 1 US Navy deck knife, which was the direct ancestor of the Kabar, was heavy-bladed and often used for tasks like cooking, opening crates, cans, and such. The commando dagger was nearly useless for camp tasks.

You're 100% right also, if you are stabbed by a 3 in knife, the compression of your body from the force of stab can actually cut 6-9 inches deep. Basically the harder your hit the deeper the blade can go, even the rib cage can be compressed

On a related note, I suspect that's why the thrusting tip on a gladius is about 3-4 inches long. Once you've thrust up to the point where the blade widens, that's really all you need to kill someone.

Another interesting thing that a lot of people (especially in the UK, where gun have reached mythical status) don't realize, is that the survivability of a stab wound vs a gunshot wound from a handgun are actually quite similar. A lot of people seem to think a handgun is like a magic death ray, and are surprised to learn that they are nowhere near as deadly as you might think. Conversely, a stab wound from a large kitchen knife is actually a lot more deadly that most people realize. Up close (which is how a lot of violent crime happens) it doesn't really matter if your assailant has a knife or a gun.

Let the fight begin about size! 😁

One could argue that the width of a blade would have more effect on the severity of a stab wound since something like a Bowie knife or butcher knife would produce a much wider wound than a stiletto or ice pick.

Thanks Matt for putting a smile on my face. A good friend and mentor of mine went into Burma with General Merrill and was one of the lucky few to walk out in the end also. He always carried a locking folding knife and always said that in his experience that larger wasn't necessary. Both he and his fellow soldiers had found that, and a sharpened folding shovel was also a wonderful tool.

Something this makes me wonder though is why Rondel/Bollock Daggers tended to be so long. By modern standards they are more short stabby swords with footlong blades. Obviously I agree with your logic, just be a good topic to discuss. Perhaps they made them large enough to use for parries in shit-luck situations?

Can’t wait to tell my ex she was wrong 😎

Great video. A couple random points in no particular order. In the States as well the overwhelming majority of knife attacks are done with kitchen knives. A cop once told me that home burglars in his area were less likely to carry weapons to the scene of a crime because they could catch heavier charges for being caught with a weapon, so upon entering a home most would make a b-line for the kitchen and pick up a knife there in case they were interrupted, and then ditch it when they left the home. A retired cop of 30+ years told me he couldn’t remember the last time he’d arrested a hooker who DIDN’T have a stolen restaurant steak knife in her purse. Flesh compresses when you hit/push on it, so a 3” blade can make a 3”+ deep wound. And in S.E. Asian martial arts like Silat that are heavily blade-oriented AND focus a lot on grappling range a shorter blade is usually preferred for it’s maneuverability and the fact that it’s less likely to over penetrate and become a risk to you as it exits the other side of the body.

Fun fact, in some place 3 inches is the max lenght of a blade to be legally carried... but if you are smart you put those 3 inches on a longer shaft....and perhaps have a 90° mounting angle for the knife...

As a Toronto paramedic, I can confirm this. We got called for an 18 year old male who had been stabbed once. He had a very small hole in his left upper back, but was walking and talking on scene and appeared unaffected. He deteriorated rapidly en route to the trauma centre, and by the time we were pulling in he went into cardiac arrest. When they opened his chest with a resuscitative thoracotomy, most of his blood volume came spilling out of his chest cavity onto the floor of the trauma room. Don't fuck with knives or with people who have knives!

"You can only have a two inch blade in Europe." **Laughs in American while legally carrying a sword**

Thank you and you are 100% correct. (graphic content warning for below information) I once worked a pretty brutal murder (as opposed, I'd say to a polite one?). 27 external stab wounds (many had multiple tracts). Most got heart and lungs. I was at the scene and autopsy. What appears to have been not a terribly long knife (certainly small enough to be easily concealed in brutal summer temperatures) went front to back well into the inside of the rear ribs. From the left side the heart and lungs were perforated numerous times as well. . For that matter, the stabs to the side were so hard, it broke several ribs and made a hole in the rib cage you could literally stick your (gloved) hand into - and that was just the blunt force, never mind how deeply that let the blade get. People think ribs stop the stab at blade length depth but remember, even in CPR one has to be mindful not to compress too hard lest one bruises the heart. Add some pointy bit of steel on the end and ... yep, beyond 3" or so it makes little difference.

Excellent video as always, Matt! Thanks!

That is NOT what she said

Great video, and Wow! comes in under 7 minutes!

When you look at bayonets the old very long ones were not to stab further through but to reach up to a man on a horse. Once cavalry charges were less likely with the magazine rifle and them machine gun the blades shrank to enough to pass through a webbing strap, greatcoat and woollen uniform and get the key 4” into play.

I mean, I thought it was pretty clear that the point of a longer stabby stick was keeping the opponent from both hurting your hand and any type of counter-stabbing. My safety natters too.

They just want everyone disarmed. It's not about safety

To make the point more precise: in case of hidden attacks (as we see them nowadays), when usually someone shouting something combined with "Akbar", it doesn't matter much how long his blade was, because 4-5 inches are lethal enough to stab someone to death. IN case of fighting, of dueling and so on, size does of course matter a lot because of reach ... THATS'S a knife. Fortunaltely in Germany we have very inconsistent knife laws. So it's perfectly legal to carry a 22 cm locking blade, as long as it's not a one-hand opening one. That speaks vor my Navaja pocket sword... just in case .

this was fairly brief, thank you Matt

Brilliant description!

But any extra length, allows easier reaching the target... hey?

Size of a thrusting weapon matters, because otherwise nobody would need a rapier instead of a rondel dagger. The size of a weapon is the difference whether the opponent's parry hits your blade, or cuts off your arm.

Thank you, Matt Easton.

"His inch is deadly!" -Baby Cakes

I agree with everything you said. And that is why a longer blade is more dangerous, because the benefit is the attacker can get at you from a farther distance. The depth of penetration is not of consequence of the length. But the fact they don't have to get as close to you DOES make it more dangerous.

Excellent! That needed to be said once and forever.👍

Agreed, Matt. The 20 inch blade is to keep the other guy with the 4 inch blade a little further away. A box cutter has a blade that is long enough for mortal injury.

Very informative. Thank you.

Good point, but not accurate enough. Longer blade has it's advantage in stabbing and here is why. Stabbing a person isn't as easy as shown in the films, so you don't always get to stab wherever you want however you want. Sometimes you must stab from the side or at point angle, and this is where longer blade will get deeper and make more damage. If for example you wanna stab someone who wears stabproof vest, you have a gap in his lower belly which you can stab upword. In this angle your short blade will not always be enough to go deep and hit a vital organ that will incapacitate an attacker. This also the case with thick clothing. If you stab someone with very thick clothing your blade will never go all the way in the body (the handguard will eventually squize against the clothing), so even if you had knife with 5 inch blade, the clothing may shorten the penetration by an inch. That's why you need a little longer blade. Besides, longer blade means you can stab from longer range. If longer blade would be useless in stabbing there was no need for longswords, arming swords, rapiers and smallswords, and defenately bayonets in war. They were used mainly for stabbing, not cutting. While they could cut soft targets, it was extremely hard, even impossible, to cut throgh armor or cut throgh gaps.

You need enough blade to reach a vital organ. Past that, yeah, it's mostly just increasing reach which ain't nothing. For defensive knives, about 6" is as large as I go unless it's a camp/field blade.

Matt!!!that watch is fantastic!!!

I am reminded of a grim fact I heard on one of those "inside prison" shows. A CO was showing the crew a collection of shanks they had confiscated over the years and remarked that 2½ inches in, anywhere on the torso, head, or neck was a potentially fatal injury

I absolutely agree that 4" is quite sufficient to be lethal, however the ability to completely penetrate the body increases the damage significantly, you have by doing so doubled the wound channel for blood to escape on both sides, not to mention increased the difficulty of medically addressing those wounds. (I'm an army combat medic)

You can see a similar effect in how faster bullets can be less lethal than slower ones. A fast bullet can punch a relatively clean hole straight through the body without depositing much of its energy in tissue. A similar thing even happens with types of radiation exposure. The general rule is that the part of your weapon that comes out of the target's back is wasted.

Thanks for the video and for sharing ⚔️

Great points, not a pun. Shorter bades can also stab deeper if not encountering bone. A 3 inch blade could cut into an abdomen quite deeply. The risk of stabbing through, and possibly into oneself is also reduced by having a shorter blade AND the carrying of a shorter blade makes draw, return, and carry placement easier. As you stated, longer's advantange is the extended distance for delivering the wound.

Great video, I hope you will have been Matt Easton in many videos to come.

Seems logical, distance from skin to vital organs or blood vessels = lethal. Even Devid Eddings knew it when he wrote The Tamuli. What a nice Katzbalger.

Great video Matt, thanks! :-) Question: Would it be valid to say that the added mass of a larger weapon beyond the point would aid penetration?

I first heard this from a certain Australian talking about RPG weapons. He pointed out that saying a dagger does less damage than a rapier or a spear makes no sense. A stab is a stab.

I can now die a happy man now that I've seen the impossible: Matt Easton making a pearl-clutching reference :)

Good information. Thank you.

Matt knew what he was doing there

As Churchill said, any time you see anything big and working well, you want to take it over.

2:35 IIRC, the Fairbairn-Sykes was sometimes deliberately dulled out of the fear that it would penetrate a bone and get stuck.

Hope this is a news flash for those in power. Almost any tool/object can be weaponised if whom ever wields it is in a state of mind to do so

That's why a slim 4" (blade) boot dagger and a 2.5" karambit are part of my EDC

Coincidentally I was reading today about someone in the UK who suffered multiple stabs to the face from a screw driver. If people are mad enough, anything is a weapon.

Great! Now do a video about how different blade profiles affect performance. Like what profiles we usually see for cuts vs thrusts vs balanced.

It's not the length of the weapon, it's where you stick it!

To be fair, a spear also allows the attacker to use the full strength of both arms and the momentum of the shaft to propel the point into the target, which increases the expected depth of penetration and hence lethality compared to a knife. But as you say, it's not about the length of the point or blade beyond a few inches.

That was a really good video, didn’t know any of that!

The ShivWorks group in the US focus a lot on short blades, about 2.5 inches or less, for the reasons that they are quicker to draw, harder for someone to stop you from drawing, when used in a punching manner the tissue compresses some with impact causing wounds deeper in than the blade length would suggest, and fundamentally because the point is less about killing someone and more about making space to get them off you.

fairbairn sykes point used to 'crumble' when hitting a bone. Then the blade would snag in the skin and clothes on the way out. So soldiers used to round up the tip.

I always recall the murder from Tom Hanks movie “Turner And Hooch” where they killed the guys on the dock buy piercing up from behind through the the bottom of the lung. The blade if I remember correctly was a standard military knife of the 4.5 to 6 inch length. It is not how deep, it is whether you can hit a vital organ or blood vessel. Most arteries are barely skin deep. In the movie reference above, getting under the ribs into a lung is actually a quite shallow wound but has deadly consequences.

A body is only about 10 inches deep? Apparently you've never seen Mississippians. It'd be more comparable to a milk cow than a normal human.

Aside from reach, which you already stated as having relevance (also note bayonets are on the end of a rifle that gives you ~2ft of extra reach), I'd still argue additional penetration does still offer value. Sure, a 3-4 inch stab may be lethal, but not necessarily immediately lethal or immediately debilitating. More penetration means more likely the person is going to instantly collapse. Also worth noting is that very few stabbing/thrusting weapons can only stab/thrust. Most have a cutting edge on them as well, and can be used to slash as well as stab.

I prefer a 8” or so screwdriver, legal everywhere. Handle wipes down clean,

The heart really ain't that far away

With a thumbnail like that I had to read the comments. Not dissappointed.

I really wish that you could have shared this knowledge at the Apple River stabbing trial that happened this month Matt. Dude killed one person, gutted another, and stabbed a total of five people with a very small folding knife- probably 3 inch blade max. The saying "it's not the meat it's the motion" is true in many instances.

So a 3 inch blade with a swept hilt is technically a rapier

*That's what she said*

I'd say you need a blade length to enter via the bottom of the jaw & penetrate into the cranial vault. Same as the bottom of the sternum, upwards through the heart, so probably about 6"-7".

Spears are in fact usually a really good example of this. The stabby bit is quite small. The bit that provides reach, is long.

It's the *width* of the blade that determines how lethal it is, hence the 15th - 16th c. cinquedea that had a blade several inches across at the hilt.

Being run through greatly increases blood loss assuming of course that every major organ was missed on the way through and it makes any difference

I would argue that if you penetrate far enough to create an exit wound, you've created two holes in your target from which to bleed out, or in the case that it's not a fatal wound, an additional avenue for infection.