Throwing knives and the science behind them

[piggarro99]

I am happy to say that I have now bought my self a set of throwing knives.

<a href="http://images.snapfish.com/334989%3B923232%7Ffp47%3Dot%3E2326%3D86%3B%3D899%3 Dxroqdf%3E23232%3B%3A5%3B87%3C3ot1lsi" target="_blank">http://images.snapfish.com/334989%3B923232%7Ffp47%3Dot%3E232 6%3D86%3B%3D899%3Dxroqdf%3E23232%3B%3A5%3B87%3C3ot 1lsi</a>

They were on ebay and there are many of them still to be sold.

now to add reason to my post i will give you some pointers in to the science and methodology of throwing knives with a small topology on how to use them.

If someone is new to throwing, he will always be told to release the knife when it points exactly at the target. This advice, which does well as a helping notion, is given by many books as well. But in reality, the knife is released earlier.
Describing it with regard to physics, the following happens: The hand makes about a circular motion around the shoulder joint. The movements in the elbow joint just change the radius of the circle and will be ignored.
Once released, the knife will fly on tangentially to the circular path (see the pink 90° angle of the trajectory to the radius, and the picture; the knife is gripped by the blade!). Perhaps some of you remember the experiment in physics at school, when the teacher swung a weight on a string around his head and then let go?
If you were to release the knife exactly when pointing to the target (blue line), it would fly straight to the ground. Rather, it must be released when the tangent of the circular path of the swing points exactly at the target (upper red line), or better a little earlier, because the ideal tangential trajectory will be affected by gravity (lower red line).
In the very moment when releasing the knife, it will be about perpendicular to the ground, then start to turn. The arm will go on in his downward swing (follow through).

Why does the knife spin?

Blade and handle (the whole knife) have the same angular speed omega in the circular movement around the shoulder joint. The end of the knife that is not gripped is farther out, therefore it is faster: its circular movement has a bigger radius (v = r * omega). If you hold the knife by the handle for the throw, then the tip will go down in the flight, the knife will be rotation clockwise around its center of gravity (seen from the right).

the best grip (in my knowledge)....

The pinch grip is used to throw light knives fast, suddenly and with force (that is some stress for your poor arm :-( The knife has to be gripped (pinched) between thumb and index finger, in a manner that it is a straight extension of your arm. You can hold it with the 2/3 of your finger that are next to your hand and the thumb (compare picture #1, my preferred method), or only with the fingertips. If you grip a heavier knife or want to throw further, you can additionally use your middle finger. If the edges are not sharp, you can use this grip also on the blade.

If the knife is not sharpened, a blade grip is no problem, just do it as described above. If the blade is sharpened on only one side, you can carefully hold it with your thumb and middle finger as shown in picture 2. I prefer not to have the knife extend such a long way in my palm, it might cut. Of course, the sharp edge faces out of your palm! You have to hold the knife so tight that it does not leave your hand early, but not too tight, especially not cramped. Only a relaxed throw is a successful one!

Dont throw knives at people, and if you do, dont fucking miss...

<a href="http://www.knifethrowing.info/images/loslassen_grafik_eng.gif" target="_blank">http://www.knifethrowing.info/images/loslassen_grafik_eng.gif</a> (actual picture of forces in motion and motion of forces)

thanks to "knife throwing info" book, 1998

<small>[ November 07, 2002, 09:47 AM: Message edited by: piggarro99 ]</small>

[Korfaction]

I was wondering about the shape of throwing knives. Their particular form is due to their particular use, I mean having a gravity center placed to facilitate the throwing. But in movies, ... (i know they're not a reference) we often see normal knives, like close combat knives in the shape (but smaller of course, who carries a 30 cm knife everywhere ? <img border="0" title="" alt="[Wink]" src="wink.gif" /> ). I was wondering when one shape or another is used ?

(Largo Winch prefers the second type <img border="0" title="" alt="[Wink]" src="wink.gif" /> )

[piggarro99]

thats a nice question, but i feel there are things that should be cleared up. throwing knives are not sharp, and can be just long pointy shanks of metal. the truth is that when you throw an ordinary knife, the (stuck on) handle wont let it fly like it should, and it buzzes, (buzzes is a term we use when a bad knife hits the target and makes a metal twang sound.) i know you see in films that they flick a knife and BAM straight in to David LO-PANS head (big trouble in little china) the truth is, that is luck...

a throwing knife is made the way it is just to glide through the air, faster than a bullet, and smoother than a frisby... It is like poetry dude...

long handle......

this is for the skewer throw, the blade does not turn at all...

curve top (looks like the top segment of a cannabis leaf)

this is for holding at the blade and letting it spin 180 degrees.

heavy handle

this is for the pinch throw, it spins every four meters (on average) so you need to be 8 meters from your target... to do the pinch throw you need to hold the knife so that there is a flat face looking at you, and then whipcrack your arm forwards from behind your ear with the flick of your wrist well timed with in it... it will whirr off for a devestating hit.... very difficult but the strongest hit by far!!!

<small>[ November 07, 2002, 04:18 PM: Message edited by: piggarro99 ]</small>

[frostfire]

sorry to inform you, but those throwing knives at ebay are F-grade quality. Sure you read alot of stainless steel 440 etc, while you might see that as fancy and assuming the claim is true, 440 is a "soft" grade. After several misses on hard surface (trees, not even concrete), your knives would become a good candidate for useless chunk of metal.

Don't worry, we're all learning...sometimes the hard way.

Good quality throwing knives are expensive. Around $30 and up, that includes the balanced-for-throwing claimed glock knives (I'd love to hear if anyone has expereince with this). The proffesional (note: has no edge, only needle sharp tip) ones can cost over $100, they use it in exhibition, circus etc etc.
But then again, what's the whole purpose of your knive throwing exercise, if it's to become a pro/exhibitionist etc, you can't go cheap.
If it's for survival (though as NBK said, knife is for sticking, not throwing), your best chance would be the readily available knives; eg: all kind of kitchen knives, good quality brand
are farberware, tramontina etc. Also you can never get poor quality knives if they are from Solingen, Germany.

Also I believe there's a shallow thread concerning this topic a while ago.

[Agent Blak]

You can throw anything an make it stick with practice. But if you have one knife and you throw and miss, you have no knife. Plus you can damage a very expensive and usefull tool.

I have one of those kershaw speed-safes(Boa; Semi-Serrated). I wouldn't dream of throwing it.

Try to learn to throws Spikes, they are more suited. All around for throwing you best bet is a shuriken. A lot less practice to master. they can be manufactored easily.

[piggarro99]

i already have a black hawke throwing knife, and quite honestly if you saw it, you could not say that it was a knife at all...

it looks like just a handle with a point... i am trying to find a picture now, but in the mean time, the knives that i have are not used for anything other than recreation...

it just a sport.

[MrSamosa]

While in San Francisco over the Summer (nice city, btw...nevermind the gay, Leftist population <img border="0" title="" alt="[Wink]" src="wink.gif" /> ), I bought myself a pair of cheap throwing knives from China Town. I throw them out in my back yard occasionally, using live trees as targets. No, they aren't the best targets and I find that they like to resist my knives a lot, but oh well.

Nevertheless, they are light-weight, soft-metal. Very cheap quality too (like anything from China Town I suppose); so cheap one of them even broke on hitting the target! :mad: Bah. For me, pinch grip on the blade has been most successful. Some people love their hammer grips and modified hammer grips and handle throws, but those have never worked. From a distance of about 3-6 meters, I can usually get a solid stick. To me, it doesn't matter if it's a professional knife or a China Town knife, so long as it sticks into the target. Personally, I don't mind the soft metal on throwing knives; it makes sharpening the point easier.

[piggarro99]

MRSAMOSA, it has been a dream of mine to actually make a throwing knife, and i can not see that it would be that hard to get it right, all you would need is a thin light shank of metal and a sharpened point that was lead from a flat handle? Any contributions

[MrSamosa]

Basically piggarro, you are right :) . Throwing knives are little more than sharpened sticks with their center of gravity at the center of the knife. So long as it is balanced and made of a rigid material, it should have stability in flight. I don't know how thin you want to make it though, but I suppose 1/8" thick would be good (that's how wide mine are).

I don't know much about the design of throwing knives, unfortunately. So I can't answer your question much further than this, sorry mate.

[piggarro99]

i am now going to risk starting another topic on making your own throwing knife...

i would rather much like you to give some feedback on that one too, thanks

[Zach]

IMHO, go buy the throwing knives. Trying to make one would'nt be worth your trouble unless you want to make it your hobby. There is alot to learn about metalurgy and forging/crafting a blade with the right temper and center of gravity. "Throwing Stars" are easier to make, but not very effective.
If you do decide to try and make your own, use an annealed file or something like that, and put your edge on with a file. This process is called draw filing (taking the file and putting it perpendicular to where the edge is to be, and slide it up and down on the peice, like you were scraping paint off of a pole or something.) and it is way easier to get a straight edge than with a grinder. trust me, I've done it.

[piggarro99]

thank you for the feed back, i am only going to try and make one as i can see the general gist of the knives. so i know that kind of balance is needed in this affair.

if you have any srecial info then please tell me what it is.. thanks again

[Maddoc]

The ability to throw knives properly is a hard task to master, as well as something that I only ever saw as a novelty, no real self-defense/attack method there. I feel the risk of giving a weapon to your enemy (i.e. by missing your mark and giving away your position) is too great. It would be better to learn good knife fighting techniques first.

Walk before you run...

I know that many elite special forces teams learn the techniques of knife-throwing (especially Russian Spetznaz troops), however it takes a long time and is still not all that effective in my view. If anyone has seen some of the videos of Spetznaz men training(e.g. "Siege Busters"), it will also show them trying to do backflips off buildings and cracking bricks with their heads. All the signs of boardom, their training would benifit if they learnt more practical uses for their skills, mainly how to carry unconcious hostages from a building full of suffocating gas... Or how to keep proper perimeter control (such as the "possibilty" that some Chechens' escaped).

[Korfaction]

I agree that throwing knives is not really a useful skill. The fact is that it's an amazing hobby, and impressive. But is stays hobby.

It is NOT recommended, whatever the situation, to throw your knife. Because after you're defenceless. So it will quasi never be used in combat or anywhere. Yet it can save your life: face to a gun, a close-range weapon like a knife is hard to use, you can throw it, kill the guy ... <img border="0" title="" alt="[Wink]" src="wink.gif" /> Really it's useless but fun.

[Harry]

Back in the mid-90's, I read about an Aussie knife throwing club. They actually taught a form of "combat" knife throwing: have 2 knives. the thrower is a large, single-edge bowie design, while the other is a 4 inch folder or gravity knife. Use the thrower to wound or distract your enemy while you close and kill with the folder.

BTW, has anyone tried Blackie Collins' Ninja? A singleedge knife, useable as a knife, guaranteed as a thrower.

My preferred thrower is an antique Mauser bayonet. The things have been a drug on the market for several years now, and USD$15 can buy one.

Harry

[Zero]

Speak of the devil. I'm actually writing a short book on throwing knives at the moment.

If you want to make your own throwing knife/knives, get some 1/8"x1" or 1.5" steel key stock from the home depot. Contary to the popular notion, I've found that the 'quality' of the steel matters little versus the design of the knife, especially it's edge. Get a good 25 to 30 degree point and a good 45 degree bevel along the edge all the way down to it and you should have a durable and quite effective knife. You can go whole hog and temper it, but that's only if you're serious about it.

I one-upped popular notion today, though, and made a set of throwing spikes from steel railroad stakes. They're about 6.5 inches long by a touch less than an inch wide, come down to impressive points (with a little nudge from the angle grinder) and will bury themselves in a tree to a depth of three inches with a good throw from five paces. They weigh about a pound, so you'll build up your arm throwing them. The things are like Lee's dungarees. You can't bust 'em.

~Zero

[piggarro99]

that is fantastic.
thanks for that, yet may i add, is there any form of characteristic that you can add to aid the flight of the knife any further?

thanks again

[Zero]

****Aside from better balance, not really. You could add a tassel or similar mechanism to act as flights, but that would impede the spin of the knife rather than help it. You could do this for small knives that you don't want to calculate spin on but rather throw them as hard and quickly as you can at an enemy as you flee...
****I suppose you could make aerodynamic enchancements to the shape of the knife with the bevels and surface textures and whatnot but at that point it's nitpicking. The difference made to the flight of the knife by a change that small would be negligible at best.
****The best thing to invest your time in is designing the overall shape of the knife properly and putting the proper edge and good point on it.

~Zero

[piggarro99]

Having made a really simple knife now, that was basically an angular piece of metal i have adorned the idea that i should try and put two points on it one each end, it will not be known as a tristan quasai, as compared to that it is shit, and the quasai is a brand name.

So what could an official name be for a throwing knife (with a blade in each end) be..

before some one points out that with no handle i cant hold it, i will make sure (as should be done) that the blade isnt sharp.

if there is any help that i can lend you while compiling this book then please let me know.

thanks again

[Zero]

****I think a knife with two points would technically be known as a double pointed knife. If you can come to grips with that logic, of course. I don't know offhand if there is any more exotic oriental name or similar for a knife of that description, but there it is.
****I could always do with pictures of throwing weapons for the book. At this rate I'll need detailed shots of a variety of throwing stars and axes, since my selection is limited and pictures on internet catalogs are generally useless. Links on throwing technique and such would always be appreciated, but I'm writing the book from the standpoint of my experience and should have that end of things covered nicely.

~Zero

[Agent Blak]

Have any of you boys watched the movie "24hrs in London." If you like to see an application of Blade throwing this is it... well kind of...

If you have seen it you will know what I mean

[piggarro99]

<a href="http://www.knifethrowing.info.com" target="_blank">www.knifethrowing.info.com</a>

that is a good site. But now i am looking for pictures of sticks (when the knife goes in)

[Eliteforum]

Link is 404. But <a href="http://www.knifethrowing.info" target="_blank">http://www.knifethrowing.info</a> works.

[Deceiver]

a few comments, this past summer i dabbled in blade forging/throwing. and from all that i have read and tried it would seem that a good throwing knife design is the tip has almost a diamond or spade(as in the card suit) shape to it ie, this &lt;&gt; i'll find a few pictures of some blades, this place has some throwing knives for under 30pounds on the ninja section <a href="http://www.spytech-uk.com/" target="_blank">http://www.spytech-uk.com/</a>
also it dosen't matter if the blade is perfectly balanced, it will still stick in the target with practise, all the center of gravity has to do with anything is how many revolutions it will have to make before the point is in line with the target again. it just changes the radius of the circle the blade makes
if you have the time/patience here is a site on how to make throwing knives
coldsteel INC. makes a throwing 'torpedo' basically an eliptical throwing knife with 2 sharp ends for half the frustration