There is no such thing as a material that is 100% bulletproof in all situations. The term bulletproof is often used to describe materials or systems that can resist or deflect certain types of projectiles, but the effectiveness of a material depends on several factors, including the type of bullet, the velocity of the projectile, the material's thickness, and the angle of impact.

However, there are materials that come close to providing exceptional protection against bullets. These materials, when used in sufficient thickness or combined in multi-layered systems, can stop or absorb the impact of many types of ammunition. Below are some of the materials most commonly used for bullet resistance:

1. Kevlar

• Kevlar is one of the most widely recognized materials used in bullet-resistant vests and armored vehicles. It is a synthetic polymer fiber that is known for its high tensile strength and lightweight properties.
• Kevlar alone can stop handgun bullets and low-velocity rounds, but for high-velocity projectiles (like rifle bullets), additional layers or different materials are often needed to improve protection.
• Applications: Bulletproof vests, helmet linings, body armor.

2. Dyneema

• Dyneema is a high-performance polyethylene fiber that is often compared to Kevlar due to its strength and lightweight nature.
• It is used in a variety of applications, including bulletproof vests, armor plates, and marine ropes. Dyneema is often favored in modern armor because it’s lighter than Kevlar while offering comparable protection.
• Applications: Body armor, helmets, vehicle armor.

3. Ceramic Plates

• Ceramic armor (often made from materials like boron carbide or aluminum oxide) is used in hard armor systems, typically in conjunction with other materials like Kevlar or Dyneema.
• Ceramics are extremely hard and are effective at shattering or deforming incoming bullets, especially high-velocity rounds like those from rifles.
• Applications: Military vehicles, personal body armor plates, bulletproof shields.

4. Steel

• Steel armor, particularly high-hardness steel such as AR500 or AR650, is used in vehicle armor and heavy-duty bulletproof vests. Steel plates are often used in tactical gear and armor because they are strong and can withstand high-velocity rounds.
• Steel is often used in combination with other materials for added protection, as it is heavy and can cause discomfort or restrict mobility in body armor.
• Applications: Armored vehicles, body armor plates, structural reinforcement.

5. Tungsten Carbide

• Tungsten carbide is a dense and incredibly hard material that is used in certain armor-piercing ammunition and can resist penetration by other hard materials. It is sometimes used in armor-piercing rounds because of its hardness.
• As a defensive material, tungsten carbide is used in some high-performance body armor or vehicle armor to protect against extreme threats like armor-piercing rounds.
• Applications: Armor plates, high-end ballistic protection.

6. Graphene

• Graphene is a single layer of carbon atoms arranged in a two-dimensional lattice. It is incredibly strong, lightweight, and has a high tensile strength. While graphene is still in the experimental stages for many uses, research is ongoing into its potential for bulletproof materials.
• Applications: Experimental bulletproof vests, potential future use in military and law enforcement armor.

7. Spider Silk (Synthetic)

• Synthetic spider silk, such as dragline silk, is incredibly strong for its weight. It’s being studied as a potential material for bulletproof clothing due to its high tensile strength and elasticity. However, its production is not yet on a large enough scale for commercial use in armor.
• Applications: Still in the research phase, with potential for future protective gear.

8. Polycarbonate (Bulletproof Glass)

• Polycarbonate is a tough, shatter-resistant plastic that can be used for bulletproof windows or transparent shields. It is often used in combination with other materials (like acrylic or laminated glass) to increase resistance against bullets.
• Applications: Bulletproof windows, vehicle armor, security shields.

9. Fiberglass

• Fiberglass is used in some lightweight ballistic armor because of its high tensile strength and ability to disperse the energy from a bullet. It’s typically not used alone but in combination with other materials like Kevlar or carbon fiber to create bullet-resistant products.
• Applications: Body armor, bulletproof panels for vehicles.

10. Carbon Nanotubes

• Carbon nanotubes are microscopic tubes of carbon atoms with extraordinary strength, stiffness, and electrical properties. Due to their extreme strength-to-weight ratio, carbon nanotubes are under investigation for potential use in bulletproof materials.
• Applications: Experimental materials for lightweight armor and high-strength protective gear.

Conclusion: Can Anything Be 100% Bulletproof?

While materials like Kevlar, Dyneema, ceramics, and tungsten carbide offer excellent ballistic protection, no material is completely bulletproof in all scenarios. Factors like the type of bullet, its velocity, and the angle of impact all affect the performance of the armor.

For example:

• Low-velocity handgun rounds might be stopped by a Kevlar vest, but high-velocity rifle rounds might require ceramic plates combined with Dyneema or steel.
• In military applications, the best armor combines multiple materials—ceramics for stopping high-velocity rounds, Kevlar for energy absorption, and steel or composite materials for reinforcement.

In summary, materials such as Kevlar, Dyneema, ceramics, and steel offer exceptional protection in specific contexts, but 100% bulletproof is an ideal that no single material has fully achieved under all circumstances. The best defense typically involves a combination of materials and strategies for different types of threats.