How Does Soft and Hard Body Armor Work?

“Do bulletproof vests actually work?” is a hugely popular question amongst first-time body armor customers, and with good reason. When your very life is on the line, it’s not enough to be “pretty sure” that you will be safe and protected—you need to know it. It also pays to understand exactly which weapons your armor is capable of protecting you from. For example, you might wonder whether a vest that stops ballistics will be as effective in protecting you from a sharp knife. 


In order to have a better understanding of how your body armor protects you, it will first be helpful to know the principles of how this armor functions. Let’s take a look at both soft and hard body armor.

Body Armor: Principles and Physics

Life safety products, including soft and hard body armor vests, are designed to minimize blunt force trauma by dispersing the energy of a round. Both soft and hard body armor is capable of stopping bullets and ballistic strikes, but the ways in which they both do so vary.

What are Hard Armor Plates?

Hard body armor uses layers of firm, durable materials, such as steel, ceramics, ceramic composites, polyethylene,  bullet-resistant fibers, and occasionally, materials like Kevlar. The vest carriers themselves are typically made from fabrics such as nylon.


Although manufacturers have put a lot of effort into making hard armor plates as lightweight as possible, the amount of protection they offer requires that they weigh more than soft armor inserts. In short, the plates resist high-powered rifle ammunition, which necessitates using heavier, sturdier materials.

What are Soft Armor Inserts?

Soft body armor inserts are made of incredibly strong Kevlar and Para-aramid materials. These inserts are placed in the front and back of vests and are made of protective ballistic material, which is held inside of a carrier. 


These vests (as well as their inserts) are usually manufactured with the end user’s size in mind, which ensures maximum comfort and body coverage. This means the end user has greater mobility. The materials for these inserts are woven together and work to spread the impact energy of bullets and other projectiles.

Do Bulletproof Vests Stop Knives?

Another frequently-asked (and relevant) question for first-time buyers is whether or not body armor is stab-resistant. According to the National Institute of Justice, the answer is not necessarily. But it is possible, depending on the product. While both of these types of armor are designed to keep something from passing through and harming the body, the ways in which they do so are different.

What is Ballistic-Resistant Body Armor?

As we mentioned earlier, both hard and soft body armor disperse a projectile’s kinetic energy through a strong, net-like material.. In some cases, the hardened panels may even be strong enough to redirect the projectile’s energy.

What is Stab-Resistant Body Armor?

This type of body armor essentially catches the weapon as it strikes, rather than dispersing its energy. The edged weapon being used is caught inside several layers of strong material before it can make a cut, while the metal element of the armor damages the blade itself, further lowering its efficiency. Simply put, while the weapon in this case may penetrate the vest’s material, it also nestles there, preventing harm to the wearer.

Pick the Right Body Armor for Your Situation

Stab-resistant body armor is not your best bet for stopping bullets, as it allows for penetration of bullets. The reverse is also true—ballistic-resistant body armor is not designed to trap the edge of a weapon in its fibers. Both of these vests are likely to offer some level of protection in cases involving either ballistics or edged weapons, but you should always use the vest specifically designed for the expected threat level of a situation.

Where Does Body Armor Direct Come In?

The short answer, then, to “do bulletproof vests actually work?” is yes. And now that you have a better idea of how the various types actually protect the wearer, you’ll be able to select the armor that is right for your needs.


Body Armor Direct specializes in both hard and soft body armor that protects users from bullets and other ballistic strikes. However, we pride ourselves on designing a variety of multi-threat vests as well, such as our Concealable Multi-Threat Level 3a vest, which protects from knife slashes. Take a look at our site for a selection of multi-threat, NIJ-certified life safety products, including ballistic-level helmets, EMS vests, concealable t-shirts, and ballistic police blankets. And don’t hesitate to contact us with any questions!