help me prove that bullet proof vests are not stab proof :)

[Hammer]

maybe if its a spectra shield vest

 

[Rogue]

He's wrong, you're right, I work law enforcement and military and have extensive experience wearing both the Interceptor vest and a Second Chance vest. Neither will stop a knife stab effectively. I have an older vest that I'd be willing to give you to stab him through though.

 

[NatePo717]

Those vests are designed for fast/hard impacts. Something like a knife is slow enough so the materail wont harden on impact so it would be just like stabbing into a piece of regular plastic. It will offer some protection though.

 

[CVSiN]

Originally posted by: Nebor
AFAIK they do provide decent protection against stabbing.

not at all.... Kevlar body armour does though.. but it is MUCH heavier and cumbersome than a ballistic vest.

so no vests do not but body armour can.

 

[HumblePie]

A regulr Kevlar, bullet resistant vest will not stop a knife attack. Most commericial forms of kevlar vests won't even stop a grouping of bullets. Which means if you get shot in the same place twice, your still dead.

So why doesn't kevlar stop a knifestab? Easy, the pressure (force) behind the point of penetration of bullet is MUCH less then the pressure (force) behind the point of penetration of a knife which gets applied TWICE in a single stab. This is because you get the initial hit form a nife, and then as resistance from the object being struck is exerted back on the knife, a person hands slips some until it hits the guard of the knife to inflict more force.

There was an episode of Body Hits on the discovery channel talking about this and why cops in England rarely wear Kevlar vests since the likely hood of being shot is MUCH lower then that of being stabbed.

 

[ZippyDan]

Originally posted by: HumblePie
A regulr Kevlar, bullet resistant vest will not stop a knife attack. Most commericial forms of kevlar vests won't even stop a grouping of bullets. Which means if you get shot in the same place twice, your still dead.

So why doesn't kevlar stop a knifestab? Easy, the pressure (force) behind the point of penetration of bullet is MUCH less then the pressure (force) behind the point of penetration of a knife which gets applied TWICE in a single stab. This is because you get the initial hit form a nife, and then as resistance from the object being struck is exerted back on the knife, a person hands slips some until it hits the guard of the knife to inflict more force.

There was an episode of Body Hits on the discovery channel talking about this and why cops in England rarely wear Kevlar vests since the likely hood of being shot is MUCH lower then that of being stabbed.

oh yes yes ive heard about them brits and their stabbing ways not mixing with bullet resistant vests. links to that would be neat too

 

[bradruth]

Originally posted by: CVSiN

Originally posted by: Nebor
AFAIK they do provide decent protection against stabbing.

not at all.... Kevlar body armour does though.. but it is MUCH heavier and cumbersome than a ballistic vest.

so no vests do not but body armour can.

Kevlar body armor = "ballistic vest."

 

[Gibsons]

Originally posted by: NatePo717
Those vests are designed for fast/hard impacts. Something like a knife is slow enough so the materail wont harden on impact so it would be just like stabbing into a piece of regular plastic. It will offer some protection though.

It's not the speed of the object. Flechettes move about as fast as a bullet, and will go right through many vests. What matters is how sharp/pointy the object is. If it's sharp enough it will fit between the fibers, so you only need to force the fibers apart to get pentration.

 

[CVSiN]

Originally posted by: bradruth

Originally posted by: CVSiN

Originally posted by: Nebor
AFAIK they do provide decent protection against stabbing.

not at all.... Kevlar body armour does though.. but it is MUCH heavier and cumbersome than a ballistic vest.

so no vests do not but body armour can.

Kevlar body armor = "ballistic vest."

no not even close..
vest can fit under clothes...
body armour goes over clothes and is very bulky...
think USMC USA and other heavy body armour you see swat teams wear

 

[darkswordsman17]

Yeah, I was thinking about the older big bulkier vests that I was shown by police, oh probably back in junior high. They were big and bulky and had a thick metal plate on the front and back, with basically just nylon straps on the side to hold it on to you. Should've thought that with technology they would've changed quite a bit since then.

Haven't really paid attention to any of the new ones.

 

[ahurtt]

Just explain to him how an armor piercing bullet is similar to the tip of a dagger. Should end the argument. Normal bullets squish and contort when they impact a target thus spreading out the force. A knife blade, like a bullet that is designed to pierce body armor, doesn't do this. It focuses all the force in one very small spot to penetrate the armor. J00 R teh Winnar!

 

[spidey07]

Tell him to watch the movie "Dune"

Gurney explains in in great detail.

 

[Kelemvor]

Tell him to put one on.. Then stab him.

 

[bradruth]

Originally posted by: CVSiN

Originally posted by: bradruth
Kevlar body armor = "ballistic vest."

no not even close..
vest can fit under clothes...
body armour goes over clothes and is very bulky...
think USMC USA and other heavy body armour you see swat teams wear

Ballistic vests are body armor. If you think "USMC USA" and "swat team" body armor, you are talking about thicker kevlar body armor. The stuff that fits under clothes is level IIIa and under. The thick, heavy, body armor is level IV and above, which also often have ceramic plates as well. Do you have any experience with body armor?

 

I've got a Level III body armor (Kelvar, not that second chance crap that kills you) and it is only for ballistics. The front of the vest has a pocket for a 1/4" plate which is stab proof. If you come at me with a knife and hits that area, i'm safe. If you stab me outside of the plated area.. i'm as good as dead.

The pocket also fits additional trauma plates.

As mention aboved, the level 4+ are super heavy.. those are not the stuff you wear outside on streets..

I love my kelvar.. it keeps me warm in winter when i wear a t-shirt.. it retains heat very well.

 

[JulesMaximus]

Remember, the slow blade penetrates the shield.

 

[spidey07]

Originally posted by: JulesMaximus
Remember, the slow blade penetrates the shield.

Gurney!!!!!!!!!!!!!!!!!!!!

 

[CVSiN]

Originally posted by: bradruth

Originally posted by: CVSiN

Originally posted by: bradruth
Kevlar body armor = "ballistic vest."

no not even close..
vest can fit under clothes...
body armour goes over clothes and is very bulky...
think USMC USA and other heavy body armour you see swat teams wear

Ballistic vests are body armor. If you think "USMC USA" and "swat team" body armor, you are talking about thicker kevlar body armor. The stuff that fits under clothes is level IIIa and under. The thick, heavy, body armor is level III and above, which also often have ceramic plates as well. Do you have any experience with body armor?

yes actually 10 years USN I ahve worn the heavier versions as well.
im not talking about vests....we all know they wont stop a blade...
but the heavier assualt versions WILL...

 

[JulesMaximus]

Originally posted by: spidey07

Originally posted by: JulesMaximus
Remember, the slow blade penetrates the shield.

Gurney!!!!!!!!!!!!!!!!!!!!

That didn't take long!

 

[bradruth]

Originally posted by: CVSiN
yes actually 10 years USN I ahve worn the heavier versions as well.
im not talking about vests....we all know they wont stop a blade...
but the heavier assualt versions WILL...

If you have experience then how can you say kevlar isn't body armor? Armor doesn't have to be hard.

 

[spidey07]

heh, I figured somebody got my reference.

Funny part is it is a decent analogy to what we're discussing - the slow blade vs. the projectile weapon.

The vest I assume is made to distributed the force. A slow or piercing blade the force can't really be distributed so it just goes through.

-edit- I thought it was common knowledge that a bullet proof vest would not stop a knife

 

[HumblePie]

Originally posted by: ahurtt
Just explain to him how an armor piercing bullet is similar to the tip of a dagger. Should end the argument. Normal bullets squish and contort when they impact a target thus spreading out the force. A knife blade, like a bullet that is designed to pierce body armor, doesn't do this. It focuses all the force in one very small spot to penetrate the armor. J00 R teh Winnar!

There are two types of armor piercing bullets. The first is VERY pointing at the end and not round at all. It's also COATED in teflon so that is can slide through the fibers easier. The other type is like hollow points. These explode into shrapnel on impact instead of compressing. The shards rip through the kevlar and go into the body. With either bullet you still need a gun to throw a round of sufficient size and velocity because while they can get through the kevlar easier the force of the blow will be deadened. Most armor piercing bullets are fairly heavy and used in big explosive guns or rifles. You aren't going to find a AP .22 round for example. Unless the armor you are trying to penetrate is toilet paper.

Also, as I said, a knife stab has around 100 times the force then a bullet. I'm dead serious. Bullets are really really light and while they are forced out at incredible speeds, those speeds drop of fairly fast. Still, force is F=ma and while bullets have plenty of acceleration, they are like a few grams of mass. Think of it like this. Try to split a 6" log with a .22 bullet. Now try with a axe. Which do you think is going to work? Hell, I doubt a .22 can penetrate more then an inch into a piece of most firewood. You could do the same thing with a knife if they weren't usually so flimsy from having such a narrow blade and the fact it would hurt your hand more.

 

[arcenite]

Originally posted by: HumblePie

Originally posted by: ahurtt
Just explain to him how an armor piercing bullet is similar to the tip of a dagger. Should end the argument. Normal bullets squish and contort when they impact a target thus spreading out the force. A knife blade, like a bullet that is designed to pierce body armor, doesn't do this. It focuses all the force in one very small spot to penetrate the armor. J00 R teh Winnar!

There are two types of armor piercing bullets. The first is VERY pointing at the end and not round at all. It's also COATED in teflon so that is can slide through the fibers easier. The other type is like hollow points. These explode into shrapnel on impact instead of compressing. The shards rip through the kevlar and go into the body. With either bullet you still need a gun to throw a round of sufficient size and velocity because while they can get through the kevlar easier the force of the blow will be deadened. Most armor piercing bullets are fairly heavy and used in big explosive guns or rifles. You aren't going to find a AP .22 round for example. Unless the armor you are trying to penetrate is toilet paper.

Also, as I said, a knife stab has around 100 times the force then a bullet. I'm dead serious. Bullets are really really light and while they are forced out at incredible speeds, those speeds drop of fairly fast. Still, force is F=ma and while bullets have plenty of acceleration, they are like a few grams of mass. Think of it like this. Try to split a 6" log with a .22 bullet. Now try with a axe. Which do you think is going to work? Hell, I doubt a .22 can penetrate more then an inch into a piece of most firewood. You could do the same thing with a knife if they weren't usually so flimsy from having such a narrow blade and the fact it would hurt your hand more.

:thumbsup:

 

[LordNoob]

Shoot him with a bow.

 

[thestranger]

Originally posted by: brunswickite
prove it by stabbing him