How Thick Should a Bulletproof Glass Be?

Many factors are considered when designing and manufacturing bulletproof glass for armored vehicles. The main goal of bulletproof glass is to prevent bullets from penetrating the material and hitting the passengers. The higher the ballistic power of the rifle, the thicker the bulletproof glass should be.

Bulletproof glass thickness ranges from 0.25 inches to 3.5 inches or more. The glass becomes heavier as it gets thicker, an important consideration when choosing the right type and thickness of the bulletproof glass.

Thickness of Bulletproof Glass

Determining the level of protection you need affects the thickness of the armored vehicle’s bulletproof glass. The thicker the glass, the more it can protect the armored car’s passengers. For example, a 21-millimeter bulletproof glass is ranked B4, which can stop bullets from a handgun. A 70-millimeter bulletproof glass, rated B7, can stand against a high-powered rifle like an AK-47.

• Level 1: This level of protection can stop bullets from handguns. It uses a nine-millimeter thick bulletproof glass, which is a good choice for gas stations, pharmacies, retail outlets, and convenience stores.
• Level 2: The thickness of this bulletproof glass can stand against high-caliber handguns, such as a .357 magnum handgun. Banks and other financial institutions use a level 2 protection bulletproof glass.
• Level 3: High-risk and high-occupancy public buildings such as schools, police stations, and government facilities utilize a level 3 protection bulletproof glass. This can stop bullets from superpowered handguns like a .44 magnum.
• Level 4 to 8: The risk of high-powered rifles attacking military applications, foreign posts, and high-level government offices requires the use of level 4 to 8 protection in their bulletproof windows and doors.

The same measure of glass thickness determines the type of bulletproof glass for armored vehicles. Still, the thickness of the glass is not the only factor that determines how bullet-resistant the car windows are. Combining materials and layers of glass can also prevent penetration of bullets from high-powered guns.

For example, a ¾-inch polycarbonate glass typically provides level 1 protection. But if combined with another ¼ inch, the level of protection can improve to 2. Adding more layers of polycarbonate or combining it with acrylic will also increase the level of security.

Materials Used for Bulletproof Glass

Manufacturers of armored vehicles use different protective materials to protect their clients. Although these materials have become more varied, there are four basic types of materials for bulletproof glass:

• Acrylic: This material is 50 percent lighter than glass. Since it is made of plastic, acrylic can be attached to other materials, such as glass. It can also be drilled and cut.
• Polycarbonate: This material is stronger than glass but is lighter by 80 percent. Polycarbonate has acrylic in its many layers, but it offers more visibility. It can stop bullets and absorb their impact.
• Glass-clad polycarbonate: In between the glass are layers of polycarbonate. This gives the material greater durability, higher bullet resistance, and better visibility. Glass-clad polycarbonate is used against the threat of M16 or AK-47.
• One-way bulletproof resistant glass: This material has an outer layer of glass and an inner layer of polycarbonate. It can diffuse impact and absorb force. Mainly used for armored cars and trucks, weapons inside the vehicle can be fired through the one-way bulletproof glass without shattering it.

The Takeaway

Understanding the level of protection each thickness of the bulletproof glass offers will help you determine what kind of armored vehicle you need. Discuss this with an armored car agent who can explain the differences in materials and thickness and why some combinations cost more. Remember that the thickness alone does not determine the bullet resistance of the glass. The materials used will also provide specific levels of protection.