An armor plate is an important component when choosing a bulletproof vest or plate carrier, because the level of protection that the user receives depends on the combination of these components. When choosing an armor plate, several key factors must be considered. First, you should carefully research the different types of armor plates, their design and features, as well as the kinetic energy they can absorb. Next, pay attention to the size and weight of the armor plate, as well as its comfort. In addition, you need to find out the level of protection provided by each specific type of armor plate and consider it in accordance with your specific needs. In this article, we will look at the main criteria for choosing an armor plate and provide useful tips and recommendations for choosing the optimal protective solution.
How does armor plate work?
First, let’s figure out the level of threats that armor plate can stop. Until the 19th century, the purpose of armor was to protect the body from cold weapons, the advent of firearms and the emergence of new artillery systems radically changed the philosophy of protection. Bullets have high kinetic energy, and it is impossible to protect the entire body with armor plates without making the bulletproof vest too heavy for an ordinary person. Therefore, a compromise was reached to protect the “lethal zones” (vital organs, injury to which leads to the death of a soldier), while the rest of the body is covered with soft armor of class 1-2 DSTU, which does not provide protection against automatic bullets but is capable of withstanding most fragments. Sometimes armor plates are used to reinforce the side areas, but this solution is also a compromise, as their inflexibility makes them less comfortable than soft armor during active movement.
To understand how armor plates work, you need to understand what they are designed to protect against. Any bullet or fragment has its own kinetic energy, which must be dissipated.
The three main parameters that test a plate’s ability to withstand a ballistic threat are bullet velocity, bullet weight, and bullet material hardness.
Let’s start with the speed of the bullet or fragment. If a bullet is traveling at high speed, it has greater kinetic energy and can penetrate the armor plate. Protection against such a scenario requires the use of thicker and stronger materials to absorb and dissipate the bullet’s energy.
The weight of the bullet is also important. Heavy bullets have more inertia. This means that the armor plate must be strong enough to stop the bullet to prevent penetration. Heavy bullets also add a lot of kinetic energy, which requires a stronger and more durable material to absorb and dissipate that energy.
Finally, the ratio of the hardness of the armor plate material to the hardness of the bullet (or fragment) core affects whether there will be a penetration. If the plate material is too soft or deforms easily, it can be pierced by a bullet, even if it is sufficiently thick (this is why high-molecular-weight polyethylene is easily penetrated by bullets with heat-hardened cores).
However, if the material is too hard, it can crack upon impact with a bullet, which can also lead to injury.
To sum up, the main task of an armor plate when encountering a ballistic threat is to dissipate its kinetic energy and protect against the fragments into which the bullet may break apart. And even if the plate copes with this task, there is another level of threat – barrier trauma, which we will discuss further.
Barrier trauma
When the energy of the bullet is transferred to a certain part of the plate, the plate deforms and bends toward the body. This is called barrier trauma. This is necessary to reduce the effects of deformation/bending of the plate toward the body at the moment the bullet hits and transfers its energy to the body. The human body consists of a significant percentage of water, so when the bullet’s energy is transferred, a water hammer effect can occur, which can result in the rupture of internal organs. To avoid this threat, various standards provide for a maximum level of barrier trauma. Thus, in the Ukrainian DSTU 8782:2018, this level is limited to 25 mm, and in the American NIJ – 40 mm. If the level of barrier injury is higher, it does not pass certification. This leads to another feature: not every plate that you bring from the US or European market will comply with DSTU, so you should take this factor into account when purchasing.
To reduce potential obstacle injury, plate manufacturers pre-bend them. For example, metal plates are made with a stiffening rib – the plate is bent outward along the central axis. Ceramic plates, in turn, are made anatomically curved to reduce the impact of this factor.
What types of armor plates are there and what are they made of?
Currently, there are three most common types of plates: ceramic, metal, and UHMWPE sheets (Ultra-high molecular weight polyethylene sheets). If we are talking about plates made of pressed high-molecular polyethylene, they are as simple as possible and consist of a single layer. If we are talking about ceramic plates, they consist of a base layer (ceramic), which are ICW plates, or two layers: ceramic plus a damper. A damper is used to reduce impact trauma. It is a protective material that should be behind the plate, in front of the body. It must be dense and thick enough to absorb the energy of the bullet and reduce the bending of the plate. It is necessary for both metal and ceramics. Finally, metal plates use a base layer – armor metal, a damper, and an anti-ricochet coating on the front.
Armor plates made of high-molecular polyethylene (UHMWPE)
The simplest type are plates made from ultra-high-molecular-weight polyethylene (UHMWPE). They are manufactured by compressing many layers of this material and, as a result, typically provide protection class 3 while remaining relatively lightweight. Because of this, they are well suited for those who primarily want fragment protection.
Regarding bullets: such a plate will stop 5.45×39 mm PS (7N6) rounds, but it will not stop certain harder projectiles – for example 5.45×39 mm PP (7N10). Therefore, if you are looking for protection against rifle rounds in general, you should consider plates with a higher protection rating.
Advantages of polyethylene armor plates:
- Light weight;
- The area of protection is always equal to the area of the plate;
- Long shelf life;
- The entire area of the plate provides effective protection;
Disadvantages:
Armor plates can be made up to class 3 DSTU due to the characteristics of the material;
Metal armor plates
Metal armor plates are cheaper, but due to their heavy weight, countries that can afford to switch to more expensive ceramic armor plates have already abandoned their use. Typically, metal armor plates are made in DSTU class 4, which allows them to withstand most standard bullets, such as 5.45 x 39 mm PS (7N10). However, as Russians are gradually switching to bullets with better armor penetration, higher-class ceramic armor is becoming increasingly relevant.
Another important function of the metal armor plate damper is to insulate the body from the metal, since during the cold season, prolonged contact of the body with the armor plate can cause pneumonia. Unlike ceramic plates, armor steel plates do not have significant barrier deformation and transfer the energy of the bullet across the entire surface of the plate, rather than at a single point, so they have better injury reduction performance.
The problem with metal armor plates is that when hit, there is a possibility of ricochet and damage from bullet fragments. To avoid this, manufacturers add a layer of felt or other special anti-ricochet coatings to their plates.
Advantages of metal armor plates:
- Relatively low price;
- Ability to withstand multiple hits;
- The area of protection is always equal to the area of the plate;
- Long service life – 15-20 years;
Disadvantages:
- Heavy weight, which makes it impractical to use plates above class 4 DSTU;
- Probability of ricochet and injury to the user by bullet fragments;
Ceramic armor plates
Ceramic plates are currently the best protection against ballistic threats. Only ceramics allow you to obtain DSTU class 6 protection (IV NIJ) with a comfortable weight of 2 to 4 kg, depending on the type of ceramic plate. Ceramics can be manufactured in combination with various components. The cheapest is a combination with aluminum oxide, a combination with silicon carbide is also used, and the most expensive and best in terms of properties is considered to be a combination with boron carbide. Plates of this type can reach a price of $750-900, but they are very durable and lightweight.
Considering that ceramics, despite their hardness, are destroyed when hit by a bullet or fragment, this type of plate requires an additional backing made of high-molecular polyethylene or aramid fibers to stop the fragments into which the bullet breaks apart. Considering that a ceramic plate absorbs energy not across its entire surface, but only at the point of impact, ceramic armor plates are prone to forming bulges at the point of impact, which are called barrier trauma.
There are two types of ceramic plates on the market. The first type is Stand Alone (SA), which has an additional backing of high-molecular polyethylene, Kevlar, or titanium, so it can be used independently. The second type is In conjunction with (ICW). They do not have a backing, so they require additional soft ballistic armor and can only be considered full-fledged plates and meet their protection class when used in combination with it. In body armor that already has ballistic packages across the entire surface, ICW plates can fully perform their functions.
Another feature of ceramic plates is that in some cases, the effective protection area is taken up by a side damper, which is needed for additional protection of the ceramic part from impact. Sometimes unscrupulous manufacturers may increase the area of this damper to reduce the cost and weight of the plate. In such cases, a “toothpick test” is used, which consists of piercing the damper with a toothpick, while the ceramic part cannot be pierced. In this way, it is possible to determine the effective area of the plate. For S-size plates, the ceramic part must be no less than 6 cm², M – 7 cm², L – 8 cm², XL – 9 cm².
Advantages of ceramic plates:
- Highest protection class 6;
- Low weight with the highest protection class;
Disadvantages:
- Even the first hits destroy the structure of the armor plate;
- The material is fragile and susceptible to falls and impacts during transportation;
- Part of the plate area is taken up by the sealant, which reduces the protective area of the armor plate;
- The most expensive type of plate to manufacture;
Standards and certification
To guarantee the quality of armor plates, they are certified in accordance with the standards existing in each country. In Ukraine, this is DSTU 8782:2018 (civilian-police), in the USA – NIJ 0101.06 (civilian-police), SAPI (military). There is also a Ukrainian military standard, which, in addition to bullet resistance, provides for dropping from a height, freezing the plate to -40 °C, heating it to +70 °C, and prolonged exposure to a solution that simulates seawater. Unfortunately, to pass such a test, manufacturers are forced to provide a significant excess of strength, which entails an increase in the weight of the armor plates.
DSTU 8782:2018
Licensed laboratories with special ballistic equipment are permitted to certify armor plates. The use of such equipment allows achieving the bullet velocity specified in the standard and, accordingly, high kinetic energy, which is very difficult to achieve under normal conditions. In most cases, shooting is carried out from a distance of 10 m (5 m for pistols), the distance between hits must be at least 51 mm, and the same distance must be to the edge of the armor plate. Usually, certification involves three control shots with the above-mentioned distance between them.
| Protection class | Bullet caliber | Bullet type | Bullet weight, g | Firing range, m | Bullet speed, m/s |
| 1 | 9×18 mm (9 mm Makarov)
9×19 mm (9 mm Luger, 9 mm Parabellum) |
Pst. (57-N-181s)
FMJ RN SC |
5.9
8.0 |
5 | 335 ± 10
400 ± 10 |
| 2 | 7.62×25 mm (7.62×25 Tokarev) | Pst. (57-N-134s) | 5.5 | 5 | 430 ± 15 |
| 3 | 5.45×39 mm (5.45×39)
7.62×39 mm (7.62×39) |
PS (7N6)
PS (57-H-231) |
3.4 | 10 | 910 ± 15
730 ± 15 |
| 4 | 5.45×39 mm (5.45×39)
7.62×54 mm (7.62×54 R) |
PS (57-N-231)
LPS (57-N-232s) |
3.6 | 10 | 910 ± 15
850 ± 15 |
| 5 | 7.62×39 mm (7.62×39) | BZ (57-BZ-231) | 7.4 | 10 | 745 ± 15 |
| 6 | 7.62×54 mm (7.62×54 R) | B-32 (7BZ-323) | 9.6 | 10 | 850 ± 15 |
NIJ
If we compare DSTU with the US Department of Justice standard NIJ 0101.06, which is also quite common in Ukraine, we can conclude that they cannot be 100 percent synchronized, since other types of bullets are common in the US. However, in general, if we make a rough comparison, the Ukrainian DSTU class 4 corresponds to NIJ class III, and DSTU class 6 corresponds to NIJ class IV. If you want to understand this issue in more detail, you should familiarize yourself with this table.
SAPI, ESAPI, XSAPI
The US military developed its own SAPI (“small arms protective inserts”) standard, which later evolved into ESAPI, and a new XSAPI standard is currently being tested. With the transition from SAPI to ESAPI, the weight of the plates increased, but so did their ballistic resistance. The transition to XSAPI ceramic plates made of boron carbide made it possible to slightly reduce the weight of the plates while improving their ballistic resistance, but such plates are significantly more expensive than other plates available on the global market. Plates that meet the SAPI standard are highly valued among the military, but when ordering such plates from warehouse stocks, it is worth remembering that the “life” of such a plate is 5-7 years, after which the material degrades and such a plate is not worth the money spent on it.
Incidentally, most global manufacturers now also use the SAPI size grid when manufacturing their armor plates.
Standard SAPI sizes:
- Extra Small — 184×292 mm;
- Small — 222×298 mm;
- Medium — 241×318 mm;
- Large — 260×337 mm;
- Extra Large — 280×356 mm;
Thus, we have reviewed several basic types of armor plates and have seen that they all have both advantages and disadvantages. Only by understanding the specific tasks for which you will be using the armor plate, can you select the ideal set for your needs. Existing armor plate certification standards will help you understand what protection class the armor plates correspond to and what threats they can protect against.
