Underwriter's Laboratory classifies bullet-resistant glass into ten levels, each designed to withstand specific types of handgun and rifle threats. This standard, known as UL 752, requires products to meet minimum criteria during testing to qualify for a rating.
A deeper understanding of these levels can assist in choosing the appropriate bullet-resistant glass for various security needs.
Understanding Bullet-Resistant Glass Standards
UL 752 standards involve rigorous testing using commonly used bullet sizes, configurations, weights, and velocities to determine the stopping ability of bullet-resistant glass. Glass thickness and material composition play crucial roles in its capacity to resist bullets and determine the protection level it can provide.
UL 752 standards involve rigorous testing using commonly used bullet sizes
In some situations, glass rated at level 1 or 2 may offer adequate protection for places like retail stores, ticket booths, or homes. For higher-risk locations, such as embassies or military facilities, stronger glass capable of halting high-powered rifle bullets might be necessary.
How UL 752 Levels Differ
Bullet-resistant glass standards under UL 752 do not follow a linear progression but are organised by threat-specific categories. Each level is crafted to resist particular threats, highlighting the importance of selecting glass that matches the potential risks faced in a particular security environment.
Details of UL 752 Levels of Bullet-Resistant Glass
Level 1: Offers protection against small caliber handguns by withstanding impacts from three 9mm full metal copper jacketed bullets. This thinner glass is often used in service windows in retail settings, ticket booths, and gas stations.
Level 2: Capable of stopping three rounds from a .357 Magnum lead-jacketed handgun, making it suitable for businesses requiring more security, like banks or financial institutions.
Level 3: Protects against large-caliber handguns, enduring three .44 Magnum rounds. High-risk areas such as courthouses and police stations might find this level beneficial. Protection against calibers from levels 1 and 2 is also included.
Level 4: Designed for larger caliber threats, level 4 withstands a single impact from a 180-grain .30 caliber rifle. This glass suits high-security entities such as government offices and other sensitive locations.
Higher Levels for Enhanced Security
Level 5: Suitable for commercial, government, and military applications, level 5 glass resists a single impact from a 150-grain .308 rifle bullet.
Level 6: This glass manages five impacts from a 9 mm handgun at specified velocities, making it viable for secure government and military applications. While similar to level 1, level 6 requires withstanding heavier fire.
Level 7: Provides resistance against high-powered rifles, withstanding five shots from 5.56 mm rifle rounds. This level suits high-risk military and governmental environments.
Level 8: Protects against assault and automatic weapon shots, stopping five 7.62 mm rounds. It’s recommended for exceedingly high-risk areas.
Level 9: Withstands a single .30-06 FMJ round, also stopping multiple armor-piercing shots, for environments needing extreme security.
Level 10: The highest level designed to repel .50 caliber rounds, catering largely to military installations requiring maximum protection.
The Underwriter’s Laboratory recognizes bullet-resistant glass in 10 levels for handgun and rifle bullets, categorized by the type of threat they are designed to stop. Products must achieve minimum stopping capabilities in testing to receive a rating. Learn more about the 10 UL 752 standard levels of bullet-resistant glass.
Understanding the Different Levels of Bullet-Resistant Glass
Testing for UL 752 ballistics standards uses common bullet sizes, configurations, weights (grain) and speeds to establish the stopping power of bullet-resistant glass. Different thicknesses and materials used to manufacture glass determine what it can withstand.
Depending on your application, you may find that a material tested at level 1 or 2 provides sufficient protection, such as for retail locations, ticket booths, or residential settings. In other cases, such as embassies or military facilities, you may want the added security offered by stronger glass able to stop high-powered rifle bullets.
UL 752 ballistic standards do not progress in a linear pattern, meaning that each level is designed for specific types of threats rather than following a simple increase in bullet resistance. Instead, they are grouped into different categories with similar requirements and capabilities. When selecting bullet-resistant glass for a security application, you want to select the type that can handle the most likely threats.
UL 752 Levels of Bullet-Resistant Glass
- Level 1: The most basic level of UL 752 glass protects against small caliber handguns. Glass with a level 1 rating can withstand impact from three 9mm full metal copper jacketed bullets. It is a thin glass that makes an excellent security solution for service windows at retail locations, ticket booths, or gas stations.
- Level 2: This level of UL-rated bullet-resistant glass can withstand three shots from a handgun firing up to .357 Magnum lead-jacketed rounds. It is a good choice for businesses that need slightly higher security, such as banks or other financial institutions.
- Level 3: Level 3 provides protection from large-caliber handguns and can withstand three .44 Magnum rounds. High-risk locations such as courthouses, police stations, and government offices might request UL Level 3 bullet-resistant glass. Protection is cumulative between the first three levels of bullet-resistant glass. This means that level 3 glass will protect against handguns with calibers up to and including .44 magnum, including those covered by levels 1 and 2.
- Level 4: UL 752 ballistic standards for levels 4 through 8 indicate that the glass is designed to withstand varying impacts from larger caliber and assault rifle bullets, whereas levels 1-3 are designed for protection against small caliber handguns. Level 4 bullet-resistant glass can withstand a single impact from a 180-grain .30 caliber rifle at 4.6 meters. It offers excellent protection against most threats to high-security commercial buildings, government offices, and other high-threat areas. Our Bullet Resistant Level 4 High-Security Guard Booth uses UL 752 Level 4 glass to provide exceptional occupant protection.
- Level 5: UL 752 Level 5-rated glass can withstand a single impact from a 150-grain .308 rifle bullet at 4.6 meters. Testing is at velocities between 2750 and 3025 feet per second. This is a high-security glass used in commercial, government, and some military applications.
- Level 6: Bullet-resistant glass with a UL 752 Level 6 rating can stop five 124-grain bullets from a 9 mm handgun at velocities between 1400 and 1540 feet per second. You will typically see this glass in high-security applications such as secure government and military facilities. Testing for levels 1 and 6 of bullet-resistant glass both use 9 mm bullets. However, level 1 glass must stop three shots, while level 6 must stop five to meet UL 752 ballistics standards.
- Level 7: UL 752 Level 7 glass can withstand up to five shots from a high-powered rifle. It is tested using 5.56 mm rifle full metal copper jacket lead core rounds at speeds of 3080 to 3388 feet per second. It is suitable for high-risk government and military applications.
- Level 8: Level 8 glass is designed to stop fire from assault or automatic weapons. It can effectively stop five 7.62 mm lead core full metal copper jacket military ball rounds, making it ideal for very high-risk government and military applications.
- Level 9: Level 9 bullet-resistant glass can withstand a single shot from a high-powered rifle firing a .30-06 FMJ round. It must also stop multiple shots from armor-piercing rounds.
- Level 10: Level 10 UL glass can stop a .50 caliber round fired from a high-powered rifle. This is primarily a military-grade glass. UL levels 9 and 10 offer superior protection against armor-piercing and military-grade bullets. They are suitable for installations requiring maximum security, such as in military applications.
