Body armor, including bulletproof vests and bulletproof plate carriers, can protect the wearer from gunfire and other projectiles. While we may think body armor is only worn by military and law enforcement members, they're also regularly worn by citizens looking to maximize safety.

When researching body armor, many people may encounter jargon and acronyms they don't understand. Many materials are used to make bulletproof inserts, and Kevlar is just one of many available materials. Some popular materials used in body armor include ceramic, steel, polyethylene and aramid.

Each body armor material offers unique advantages and can safeguard the wearer from various projectiles and ammunition types. SAPI and ESAPI are two styles of body armor that are regularly used by the military for ballistic protection. Learn more about SAPI and ESAPI armor, their benefits and what sets them apart.

What Are SAPI Plates?

SAPI body armor stands for small arms protective inserts, and these inserts are typically made of ceramic with an external composite coating. SAPI plates are often used by the United States military and come in many sizes, ranging in weight from 3 pounds to 5.5 pounds.

In many cases, a soldier will wear a SAPI plate inserted in the front and back of a ballistic vest, with two additional plates on the sides. As the name suggests, SAPI plates are designed to stop smaller rounds from perforating a bulletproof vest and causing injury. While SAPI was originally used in interceptor body armor, it's now considered the standard insert for improved outer tactical vests and modular tactical vests.

SAPI plate cuts are a unique system of five plates used at various locations on the body. Typically, SAPI inserts aren't found in civilian markets as easily because they're standard equipment within the military. Most SAPI inserts feature a 45-degree cut down each shoulder and come in numerous sizes.

The SAPI style makes it more comfortable to shoulder a rifle while still providing a high level of protection for the wearer's body. SAPI inserts also feature rounded corners for added flexibility and don't press into the body uncomfortably. 

Most SAPI body armors are made of ceramic and feature a National Institute of Justice (NIJ) rating of level III. A level III rating means the body armor can stop most intermediate rifle rounds and protect the wearer from injury. SAPI plates are a lightweight option, allowing for adequate mobility.

Because SAPI inserts are made of ceramic, they share the same benefits of SAPI body armor, including high-performance armor protection. Ceramic body armor boasts high hardness but superior lightweight material that's significantly lighter than some body armor materials.

Ceramic body armor offers consistently dependable defense from unexpected threats, rounds and projectiles. When SAPI armor is paired with a bulletproof helmet, bulletproof masks or other active threat equipment, the wearer's risk of injury is significantly reduced.

What Are ESAPI Plates?

ESAPI stands for enhanced small arms protective inserts. These inserts were created to improve the utility and benefits of SAPI plates. In 2005, the U.S. military began introducing ESAPI plates on a wide scale due to their many benefits. ESAPI quickly grew in popularity as a new generation of body armor, as they're designed to meet NIJ level IV protection and can withstand certain armor-piercing rounds.

While ESAPI plates are nearly identical in shape and size to SAPI plates, they're a little denser and heavier. The added weight of ESAPI plates provide a higher level of protection and can stop stronger rounds than SAPI. In most cases, ESAPI plates are made using high-quality boron carbide ceramic, the same material used for certain armored vehicles, including tanks.

Although ceramic armor and inserts are incredibly strong and reliable, you should still be careful when handling the inserts. Ceramic armor may be slightly more brittle than other materials, which can crack or fracture if dropped. Even if you may not notice damage, ceramic armor may have hairline fractures or cracks not visible to the naked eye. How much ESAPI plates cost depends on the size.

In general, ESAPI plates are often more expensive than SAPI plates because ESAPI plates are denser and offer additional protection. Most ceramic inserts and armor have an average life span of around five years. At the end of this time, ceramic body armor needs to be replaced to ensure effectiveness and reliability.

Because ESAPI has become a new standard for the military, these armor inserts are often unavailable to the average citizen.

ESAPI vs. SAPI Plates

While SAPI and ESAPI plates are similar in certain aspects, they also have several unique factors to consider. Understanding the difference between SAPI and ESAPI plates can help you determine which is right for your specific application. One of the main differences between SAPI and ESAPI plates is their NIJ level.

The main difference between ESAPI and SAPI plates include:

Plate Shape and Cut

SAPI and ESAPI plates have the same cut and shape and only vary in material density. A traditional SAPI and ESAPI plate design are similar to a shooter's cut, but SAPI and ESAPI plates may have slightly more material than a shooter's insert.

Shooter's cut, also known as swimmer's cut, is often ideal for active shooter applications because the cut allows the wearer to shoulder a rifle with enhanced comfort and positioning without minimizing organ protection. On the other hand, SAPI and ESAPI feature a more traditional body armor shape and cut often used in military armor systems.

Considering an 8″ x 10″ plate, the area of a shooter's cut is around 2.22″ x 4.45″. Conversely, SAPI and ESAPI armor have an area of approximately 1.81″ x 2.61”.

Plate Size

Typically, commercial body armor plates come in standard sizes, including 8″ x 10″, 10″ x 12″ and 11″ x 14″. However, the original SAPI plates were modeled after a different sizing method to fit the standard plate carriers used in the military.

ESAPI plates can be tailored to the wearer for the best and most secure fit. In general, only very tall or short people may need plates that are not standard commercial sizes.

Protective Body Armor and Plate Carriers

Atomic Defense is the leading provider of bulletproof vests, plate carriers and other tactical equipment to ensure your safety. We proudly offer the best and most effective active threat equipment, prioritizing premium materials for dependable, reliable coverage.

We offer a wide range of tactical equipment and ballistic armor. In addition to tactical vests and plate carriers, we offer bulletproof helmets, bulletproof visors and bulletproof masks. Our product line also includes bulletproof backpacks, bulletproof blankets, tactical gloves, assault vehicles and more.

Contact Atomic Defense online to learn more about our body armor and tactical equipment.