The ol’ reliable military flak jacket. Many military veterans who served in the Vietnam War in 1955 would be no stranger to these flak vests due to the large number of mines that were planted by both sides to prevent quick advances by infantry troops, much like the North Vietnamese used during the First Indochina War.

In general, troops would wear military flak jackets to protect themselves from high explosive weapons such as mines, grenades, anti-aircraft artillery, and even some variation of shotgun ammunition that would have their case fragments (frags) blow soldier’s socks off in a blink of an eye. A single slim sliver of metal from a mortar round the size of a toothpick entering your heart will kill you, and has.

U.S. Army soldier wearing a military flak jacket, Vietnam, 1971 (Wikimedia Commons). Source:
US Army soldier wearing a military flak jacket, Vietnam, 1971 (Wikimedia Commons)

Yup, the military flak jacket, protecting our military men since the 1860s. Wait, what? You might be asking yourselves, were there flak jackets in the Civil War? I thought they only had bulletproof vests! For all of you history buffs, sit back and let us take you through a bit of a blast to the past, no pun intended, of course.

Are Flak Jackets, Bulletproof Vests, Kevlar All The Same?

The military veterans reading this would probably get a laugh out of this question, but let’s face it, not many people know what the difference is between flak jackets, bulletproof vests, and kevlar. So to all our military guys out there reading this article, if you ever encounter someone asking about the difference, we think it’s best that they’re informed!

Now, for those confused about the difference, this might stem from the fact that people often interchange these three terms. Even video games sometimes list these gear as the same thing! So don’t be ashamed if you’re only finding out now. It’s really something that everybody seems to get wrong the first time around.

Let’s take you through the basics.

Kevlar seems to be the most searched body armor that pops up whenever you do a google search. So it may surprise you (or not) that Kevlar, the synthetic fiber itself, was made by American Chemist Stephanie Kwolek for DuPont in 1965. Simply speaking, Kevlar is the material or component used in making soft-body armor, which is different from a flak jacket. It was first used for racing tires, but they discovered that it could be used in the body protection industry because of its high tensile strength to weight ratio, making it 5 times stronger than steel.
The Improved Outer Tactical Vest (IOTV) used by the US military (Wikipedia/Wikimedia Commons)

Kevlar is what the military uses to make its bulletproof vests, combat helmets, and even as spall liners in armored vehicles. Most notably, the Nimitz-class aircraft carriers use Kevlar to reinforce certain areas of importance. It’s thinner and lighter than flak jackets and is mostly used by firefighters due to their high heat resistance and police officers (even SWAT) for body armor. It’s a common misconception that bulletproof vests stop all types of bullets, so it’s best to call them “bullet-resistant” as there are subcategories of ballistic vests with specific uses, most likely according to the type of ammunition it would stop.