In battle there are no trifles. Every gram of gear, every centimeter of protection is either a chance to survive or a fatal weakness. One of the most important protection parameters, which is often forgotten, is backface deformation (BFD). If you wear body armor or plan to buy a new one, this information is critically important.
What is backface deformation?
When a bullet or fragment hits the armor, it stops it — that's its main function. But the impact is "transmitted further", into the body. And even if there is no penetration, the body sustains an injury through the deformation of the plate's inner surface — its deflection toward the body. It is precisely this phenomenon that is called backface deformation.
If the armor "caught" the bullet but flexed heavily, you can suffer:
– rib fractures,
– internal organ contusions,
– heart or lung trauma,
– painful hematoma shock.
So armor that isn't penetrated ≠ no injuries. If the BFD is too large, you can sustain a serious injury, sometimes even incompatible with life.
What are the permissible BFD limits?
The requirements for permissible backface deformation are established by international standards. According to the NIJ (the standard of the US National Institute of Justice), the maximum permissible backface deformation is 44 mm. According to DSTU, this figure must be no more than 25–35 mm depending on the type of armor.
For reference: 44 mm is almost half the width of a small palm. Just imagine the force of the impact transferred into the body.
However, it's important to understand that under the standards, measurement of the damaged surface is carried out in so-called ballistic clay, so the consequences of a hit for a person may differ depending on the location of the injury, skin elasticity, the level of muscle development, the percentage of subcutaneous fat, and so on.
Can backface deformation be zero?
No, backface deformation cannot be completely eliminated. It's physics — any impact has momentum that is transferred into the material and further into the body. But its effect can be significantly reduced.
There are two ways to reduce BFD:
- Structural reinforcement of the plate itself — using additional layers of Kevlar or polyethylene to create a damping layer on the plates.
- An anti-trauma pad — special inserts in the body armor or plate carrier that dissipate the shock wave.
The clothing, the cover holding the armor and the ventilation also partly act as a damper. Still, you can always play it safe with additional protection — for example, our MCA panels. They attach to plate carriers, increasing your protected area while also serving as an additional damping layer.
How can I check a product's backface deformation before buying?
This information must be contained in the test-firing protocols — the depth of the dent is indicated in the case where there was no penetration of the armor. You definitely shouldn't believe stores that claim BFD is absent in their products — that's impossible.
If possible, look at buyers' reviews of the manufacturer: warriors often share their "impressions" of products after using them in battle. We publish such photos and videos on our Instagram page.
Protection is not only about strength, but also about ergonomics, cushioning and thoughtful details. In modern combat it's important not only to stop the bullet but also to preserve the ability to move. Armor that "holds" the impact but breaks your ribs in the process doesn't save you — it creates an additional threat. Don't neglect dampers: if there's an opportunity to use an additional protective layer, do it, to minimize the risk of a backface injury.
