Is Kevlar Stab-Proof?

The Batman series with the dark, cowled vigilante has increased our belief in the formidable power of Kevlar to stop just about every projectile you could launch at its wearer. Whether daunting fiction or not, that should leave you thinking more about it. Just how tough is Kevlar?

Of course, not everyone is a security personnel or part of a private army, getting subject to knives on every other day. However, you could get perhaps get involved in a knife fight in a bar. So, could such Kevlar armor protect someone wearing it from a mugger with a knife on a dark street? A homicidal man on the tube? A desperate armed person looking for close combat? Well, let’s find out.

Kevlar is a trademarked polymer of stacked fibers known chemically as poly-para-phenylene terephthalamide. It is said to be up to ten times stronger than an equal weight of steel. This is due to its high tensile strength. The high tensile strength it possesses makes Kevlar resistant to ripping under tension. This is an ideal property of an object that should repel direct cuts during an attack.

The translation of the above information to knife fights? It is interesting to note that stab vests are different from bulletproof vests based on their tensile strength. While that difference is captivating reading for another day, let us now focus your pondering on Kevlar against knives being, in fact, a Kevlar stab vest versus a knife-wielding stabber.

Stab vests come in 3 levels that classify the amount of force behind the strike, that the vest can withstand:

· Level 1 withstands up to 24 Joules (17.70 ft/lbs)

· Level 2 withstands up to 33 Joules (24.34 ft/lbs)

· Level 3 withstands up to 43 Joules (31.72 ft/lbs)

The above are United States classifications for stab vests. The amount of force in Joules is similar to the work done in lifting an equivalent number of apples in one's hand. It shows careful preparation on the part of stab vest manufacturers, in that they know that the force behind a knife cut varies a fair amount. They are equally aware that the edge of a knife is thin and maximizes force.

Would this be enough to prevent a stab injury? As a caution, these vests are resistant to stabs and are not stab-proof. You will never see one that prevents you from being stabbed 100%. What they will do for you is offer you more protection than facing a knife or broken bottle bare chested.

The ranges of force for areas covered by the vests are within the ranges found in assailants and as such are approved. For the better part, you should be covered by the Kevlar vest as far as its caveat goes. However, if you want more protection, you will have to go for a higher level Kevlar. Or perhaps just put on a bulletproof vest.

Note: these vests will not protect you from an assailant with an icepick, axe, or bayonet.

For any further questions, please do not hesitate to contact us at toby@gdcalm.com.