
HOSDB and NIJ: The 2 most used ballistic standards for body armor

A bulletproof vest is not “just” a vest; ballistic body armor is produced worldwide using a range of materials to achieve bullet resistance.
This guide explores the differences between Aramid and UHMWPE, highlighting the most widely recognized and utilized ballistic materials today.
The materials used in a bulletproof vest determine its flexibility, thickness, weight, and the types of bullets it can stop. As a result, choosing the right vest can feel overwhelming, as it may be challenging to navigate and understand which options best meet your needs.
However, all bulletproof vests have one thing in common which is that they should be able to stop the same type of cartridge, whether made to the:
The above standards are all for soft body armor.
Before we discuss the various bulletproof materials, it’s essential to understand the differences between them. There are two primary materials used in body armor.
The first material is UHMWPE which is an ultra-high-molecular-weight polyethylene, which is a chemical polymerization process in which monomers are converted to polymers.
UHMWPE is VERY strong versus its weight, and has a high resistance to both ballistic, sharp edged and pointed instruments. UHMWPE is not only used in bulletproof and stab-proof vests, but also in clothing, fishing lines, cut resistant gloves, aircraft containers, sports equipment, clothes, etc.
Main Properties of UHMWPE:
UHMWPE is produced by several manufacturers, with some of the most recognized brands being Endumax by Teijin, Dyneema by Avient, and Spectra Shield, Gold Shield, and Gold Flex by Honeywell.
Additionally, many lesser-known brands also manufacture UHMWPE for bulletproof vests.
Dyneema is one of the most widely used polyethylene materials in bulletproof vests. According to Avient, Dyneema is up to 15 times stronger than steel and 40% stronger than aramid fibers, considering its strength-to-weight ratio. Avient offers a variety of Dyneema fibers, each with unique properties tailored to different applications..
As you can see, there are many material options, which means that bulletproof vests made from Dyneema can vary significantly in flexibility, weight, and thickness. Many body armor manufacturers blend Dyneema with aramid fibers to optimize ballistic protection.
For instance, Protection Group Danmark produces a lightweight ballistic vest using Dyneema SB71, weighing only 4.5 kg per square meter. This results in ballistic inserts for a large vest that weigh just 1.24 kg. However, Dyneema SB71 is relatively rigid and lacks the flexibility of other Dyneema types, such as SB115, which is the lightest, most flexible Dyneema – though it is also very costly.
This also means that Dyneema is often mixed with aramids to get a flexible and lightweight bullet proof vest.
An example of this is Honeywell with their Gold Flex and Gold Shield fiber, made from Honeywell’s own UHMWPE fiber, and Kevlar. This bulletproof vest is made of both aramid and UHMWPE, which benefits from the unique properties of both materials, providing a flexible, lightweight and strong bullet proof vest made of aramid and UHMWPE.
Read more about our bulletproof vests.
Aramid is a synthetic fiber that was created back in the 1960s by Stephanie Kwolek. The fiber is known especially from Dupont Kevlar, which was the first company with a commercial version for bullet proof vests, followed by Twaron from Teijin. Aramid is commonly used in both bulletproof and stab-proof vests due to its exceptional strength and flexibility. It has demonstrated stability and reliability over many years, making it a trusted choice for body armor.
The main characteristics of Aramid:
For bulletproof vests, there are 2 different types of aramids. UD (unidirectional aramid) and woven aramid.
Unidirectional aramid consists of 2-4 layers of aramid fiber plied in a 0°/90° configuration or a 0°/90°/0°/90° configuration. UD aramid is typically a bit more rigid than woven aramid; however, this material has the advantage that it is strong and has a low weight.
Woven aramids are aramids that are woven together in a more traditional manner. Here, there are many different weaving methods that affect the strength and overall weight of the material. Woven aramid is often very flexible and can stop contact shots from a distance of 0 meters.
UD and Woven aramid are made from Kevlar thread from Dupont, Twaron aramid from Teijin or Artec from Pro-Systems S.p.A.
Woven aramid is often much more flexible than UD aramid, and can bend in several directions where UD aramid is more rigid. (There are, of course, different qualities, and therefore the flexibility of UD aramid can be different, for example the UD42 from Teijin which is an extremely flexible aramid UD that immediately shapes to the body of the user.)
It’s important to understand that you can both buy the finished bulletproof material at Teijin and Kevlar, or choose to buy their thread, and then develop their very own UD aramid or woven aramid with their thread.
At Protection Group Denmark, we have made use of UD aramid from Teijin, which provides one of the market’s thinnest and most flexible aramid bullet proof vests, with a weight of 5.5 kilos per square meter (1.5 kilograms for a size large) with a thickness of only 6 mm. The UD aramid is very flexible and perfect for concealable body armor solutions.
Read more about our bulletproof vests.
Kevlar is the most well-known and widely used aramid globally. Most people recognize the term “Kevlar,” often associating it with bulletproof products due to its reputation for strength and protective capabilities. However, the fiber is also used for aircrafts, ships, car parts (tires), engine parts, different industries where you wear cut resistant gloves/shirts, fire proof clothing, brakes, etc.
Kevlar is generally more flexible than UHMWPE and is available in various qualities. This variation arises because many manufacturers purchase the raw fiber and weave it into their own proprietary designs, resulting in a broad range of quality. Consequently, body armor may range from lower-quality Chinese-spun Kevlar to higher-quality European-spun Kevlar.
Kevlar XP is one of Dupont’s leading solutions, and according to Dupont this solution provides up to 15% less back face deformation and the total solution will have at least 10% less weight compared to similar aramid solutions. Twaron from Teijin reminds a lot of Kevlar, as Teijin also offer thread and self-developed solutions.
Teijin has developed the Twaron LFT-AT / AT flex liner, which is a BFS solution that adds 1-2 layers AT flex that gives up to 40% less back face deformation. For example, this aramid can be used with Dyneema, Kevlar or Spectra to achieve a thin and flexible solution with a low Back face signature.