Kevlar vs. Medieval Weapond?

How would a “bullet-proof” Kevlar vest fare against a medieval Sword? What about a mace or war-hammer? Would it provide protection from these weapons?

WAG here, but I’d say not so much. It might keep the sword from doing much in the way of cutting damage, but there’s still gonna be a pretty good lick from a man swinging a heavy piece of metal at ya. For a mace or war hammer, even more so. Kevlar can stop a bullet from penetrating a human body, but it’s not going to mitigate crushing damage from a blunt weapon.

Also bear in mind that a kevlar vest only protects the torso…the arms, head, and neck are wide open, and subject to getting lopped off. Think I’d rather be wearing plate armor against those weapons.

I’m sure a better explanation will be along soon but a kevlar vest is no more effective than any other thick clothing. Kevlar works by being very resistant to pulling apart/snapping of fibers. Cutting tools like knives and swords still slice it fairly easily. Blunt force like a mace would be completely transferred to the wearer.

Even people wearing vests are sometimes seriously injured by the impact of those bullets. The vest prevents them from penetrating but at the same time your body still absorbs the full amount of force carried by that bullet.

I’d have to think that if you’re in a situation where you could be hit by either blunt weapons or sharp weapons or projectiles, the best defense would be a suit of full platemail, with Kevlar underneath that in place of the usual padding. People agreed with me on the last thread that brought up this question but noted that the weight would be extremely heavy.

Yep. I read a news story several years ago about a guy who stabbed himself in the chest while wearing a kevlar vest. He stumbled out into another room where other people were, said something like “oh shit, I did it!” then collapsed and died. This led investigators to believe that he was just playing with the vest and didn’t think that the knife would penetrate it, and that he had not intended to commit suicide.

Plate mail itself was extremely heavy. However, I saw a show where they built authentic plate mail armor for about half a dozen guys and experimented with it. One guy injured one of his joints (knee maybe, I can’t remember) from running around with all of the extra weight, but mostly they were all able to run and jump without too much difficulty. The idea that this stuff was so heavy that you could hardly move isn’t the way it really works, and I suspect the same would be true even with a bit of extra kevlar thrown into the mix.

IIRC, a full suit of plate mail weighs about what the average U.S. Soldier carries into combat, and is distributed much better.
Saw a wizened old guy on TV doing summersaults in full armor, your results may vary.

Having tried to cut Kevlar cladded cable, I’d think the stuff should provide some kind of protection against hacking-type cuts, but a sharp rapier point? Probably not.

20 - 30 kilograms (that’s 45 - 65 pounds, I think)
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A yeoman with an English long bow could easily drive an arrow deep into a horse or through chain mail.
Few archers today could begin to pull a long bow.It would likely be very effective on Kevlar.

30 to 65 pounds is a decent range for fully articulated plate armor. The actual weight will depend on the configuration, the style, and the purpose. A suit of jousting armor isn’t going to be used on the battlefield by anyone with any sense, and a suit for a knight fighting in the “english style” (on foot) might be differently configured, and therefore will likely weigh less than one for a mounted warrior.

In either case a properly made suit will have it’s relatively low weight spread out over the body evenly, and will be properly articulated so as to essentially feel like a protective skin around the body.

Unless you are facing modern projectile weapons I’d say dump the kevlar and stick to the padded and reinforced arming jacket or doublet you’d likely wear underneath the plate. The whole thing is meant to work together against the weapons of the time.

Kevlar, AFAIK isn’t very cut resistant. However, Spectra is, and they use that in vests too. In fact, many Police officers have gloves lined with it just to prevent cuts. They also use it in butchers gloves (or real steel mail).

They also make cut resistant gloves out of Kevlar (like these).

Here’s what I’ve learned in some basic research. “Bullet proof” vests are designed for exactly that, bullets. They offer some protection is a slashing type attach, just because there is more mass of stuff between you and the knife. In the case of a stabbing type attach, they don’t offer a whole lot of protection.

Recently (last five years maybe?) Stab resistant vests have become available. In the last two or three many manufactures began to combine both stab and ballistic vests into the same vest.

here is some info on the ballistic protection and stab protection from the National Institute of Justice.

I’ve had worse.

I don’t know about Spectra and can’t compare the two, but I made a Kevlar canoe a while ago. I can assure you it is very difficult to cut.
The sheets I have can easily be punctured though, as the fibers can be easily pushed out of the way by a sharp object

It’s just a flesh wound.


Kevlar vests stop many bullets but much of the impact gets through and heavy bruising results. On TV, it’s not much of a big deal. More of deal in real life.

A war hammer would probably do good choice against kevlar.

Against a slashing type of sword strike, Kevlar would be good protection but not totally. If you look for gloves to protect against cuts, about the best you find are “cut-resistant” and not “cut proof”. Cut proof would mean extra weight, less mobility.

Swords meant to kill or wound by stabbing (like a gladius) would probably do OK against Kevlar depending on what the person wearing the Kevlar is doing (would take a more stout strike than normal and they aren’t just going to be watching). Kevlar would add protection.

A long bow - with something like a 100 to 120 lb. pull and a heavy armor-piecing arrow - would make short work of Kevlar is my guess.

If you are designing, it seems like you’d want something like a thin Gore-Tex underlayment, articulated and overlapped cermamic plates (make them replaceable) and Kevlar on top. Bulky but what can you do? Seems like you need something to spread out the pressure of impact and resist cutting.

From this thread, check out liquid armor!

Even “stab proof” vests offer pretty shitty stab protection. The NIJ uses a rather dull ice pick when doing their classic Ice Pick test. I once saw a guy trying to demo some stab proof vests when they were first coming out. He left the NIJ Ice Pick back at the office (in some other state. this was a convention.) So he just thought he could pick up a normal ice pick from the hard wear store. The real ice pick penetrated three vests in a row before he decided to stop and figure out what the problem was.