Security window film is frequently proposed for openings where the actual requirement is stopping gunfire. Armortex® is a specialty manufacturer of bullet, blast and forced entry resistant products, including bullet resistant glazing rated to UL 752, and the distinction between film and rated glazing is one of the most consequential specification decisions on a security project. Film is a legitimate product with defined uses. It is not glazing, it does not carry a UL 752 rating, and it will not stop a projectile. This article explains what film does, how bullet resistant glazing differs, and how to determine which product a given opening requires.
Quick Answer
No. Security window film does not stop bullets. Film is typically 3 to 8 mils thick, while bullet resistant glazing is ¾ in. to 4 in. thick. Film can reduce spall, limit injuries from accidental impact and vandalism, and delay forced entry. Stopping gunfire requires bullet resistant glazing installed in a bullet resistant frame. Armortex manufactures glazing rated to UL 752 Levels 1 through 10.
What Is Security Window Film?
Security window film, sometimes marketed as ballistic film or bulletproof film, is a thin layer applied to existing glazing. Typical thickness is 3 to 8 mils; for reference, 30 mils is about 1/32 in., roughly the thickness of a credit card.
Film can be beneficial as an enhancement to non-security or non-bullet-resistant glass, and it can provide a non-spalling product where one did not previously exist. What it cannot do is stop bullets. The governing test is straightforward: if a product cannot meet a UL 752 ballistic standard, it is not truly bulletproof.
What Is Bullet Resistant Glazing?
Bullet resistant glazing is a rated barrier material manufactured specifically to resist ballistic impact. Armortex manufactures bullet resistant glazing in all-glass makeups and in combinations of glass and laminated polycarbonate, suitable for interior or exterior applications. These products provide the durability of glass together with the lighter weight and aesthetics of polycarbonate, and some can be UL Listed as no spall or low spall.
The primary use of these products is bullet resistant protection from handguns, rifles and shotguns.
How Does Bullet Resistant Glazing Work?
Ordinary glass is brittle and hard, so it cannot deform in response to a localized impact. Bullets pass through standard commercial windows with little to no loss of energy, providing no protection to anyone in the line of fire.
Bullet resistant glazing is fabricated as a laminate or composite of multiple alternating layers of glass and plastic. Polymers used in a glass laminate include ethylene-vinyl acetate (EVA) or polyvinyl butyral (PVB), which hold the layers together following a break. Rather than passing rapidly through a single pane, the projectile’s energy dissipates through the successive layers, slowing it to a stop.
The term “bullet-proof” is a misnomer. Repeated impacts gradually reduce the integrity of the product, which can cause spalling — shards breaking free on the protected side — or allow subsequent rounds to penetrate the laminate. The performance claim is resistance to a defined threat, not invulnerability.
Security Film vs. Bullet Resistant Glazing
The two products differ in construction, rating, and the problem they are designed to solve.
| Security window film | Bullet resistant glazing | |
| What it is | A film applied to existing glazing | A laminate or composite of glass, or of glass and laminated polycarbonate |
| Nominal thickness | 3 to 8 mils (0.003 in. to 0.008 in.) | ¾ in. to 4 in. |
| Stops bullets | No | Yes, to the rated level |
| UL 752 rating | Not rated to UL 752 | UL 752, 11th edition, Levels 1 to 10 |
| Spall performance | May reduce spall | Available UL Listed as no spall or low spall |
| Primary function | Glass retention, injury reduction, entry delay | Bullet resistant protection from handguns, rifles and shotguns |
| Frame requirement | Applied to the existing frame | Must be installed in a bullet resistant frame |
| Appropriate for | Accidental impact, low-level vandalism, thrown objects, some blunt force attack | Cashiers, courts, secure facilities, critical control rooms |
How Thick Is Bullet Resistant Glazing Compared With Film?
The thickness difference is the clearest way to understand why film cannot substitute for glazing. Film is measured in thousandths of an inch; bullet resistant glazing is measured in inches. The chart below uses a logarithmic scale because the two products cannot otherwise be shown on the same axis.
Figure 1. Nominal thickness of security film compared with bullet resistant glazing, on a logarithmic scale. Source: Armortex.
This is why added thickness does not convert film into a ballistic product. Even relatively thick film remains thin compared with ballistic glazing, and the gap is roughly two orders of magnitude.
What UL 752 Levels Are Available?
UL 752 is the widely recognized safety standard developed by Underwriters Laboratories for evaluating and rating the ballistic resistance of architectural building components. Armortex products are tested to UL 752 Levels 1 through 10, and Armortex bullet resistant glazing is rated to UL 752, 11th edition, Levels 1 through 10.
| UL 752 levels | Threat category | Example threats | Typical application |
| Levels 1 to 3 | Handgun | 9 mm, .357 Magnum, .44 Magnum | Interior reception desks, visitor processing and security checkpoints; typical bank and convenience store requirements |
| Levels 4 to 8 | Rifle and submachine gun | .30-06, 5.56 mm, 7.62 mm | Exterior windows and perimeter openings where higher-energy impacts are credible |
Levels 9 and 10 are within the range Armortex supplies; threat definitions for those levels should be confirmed directly with Armortex for the specific application. The appropriate protection level depends on the threats the end user is protecting against. Handguns are the most common weapon used in shootings due to their concealability and accessibility, so high-powered handgun protection is the most widely used across applications. High-powered rifle protection is available where specific rifle threats, such as military or tactical law enforcement scenarios, are anticipated.
UL 752 should not be confused with NIJ standards. UL 752 applies to bullet-resistant building materials such as glass and walls. NIJ standards are used primarily by the federal government, including military bases, and are designed for dynamic environments. The two sets of levels are not interchangeable.
Which Glazing Makeup Should Be Specified?
Once rated glazing is established as the requirement, the next decision is the material makeup.
| Bullet resistant polycarbonate and acrylic | Glass-clad polycarbonate | |
| Composition | A monolithic or laminated sheet of polycarbonate | Multiple layers of glass and polycarbonate bonded with an interlayer film |
| Weight | Lightweight | Heavier, due to the glass layers |
| Impact behavior | Excellent impact resistance, designed to catch bullets; reduces spalling | Higher levels of ballistic protection, suitable for a wider range of threats |
| Surface durability | Prone to scratches and wear unless an abrasion-resistant coating is applied | Outer glass layers provide superior scratch and weather resistance |
| Best for | Interior security windows and barriers, weight-sensitive applications, lower-risk commercial entryways | High-security exterior applications, government buildings, military bases, transactional areas |
Where Is Bullet Resistant Glazing Used?
Armortex bullet resistant products are specified across a range of environments:
- Commercial buildings, including banks, retail stores and offices
- Government facilities, including courthouses, embassies and military buildings
- Public spaces, including schools, transportation hubs and arenas
- Police stations, cashier booths, check cashing facilities and convenience stores
- Private residences in high-risk areas, including safe spaces and panic rooms
Within a facility, the highest-value openings are typically the primary public entrance and exterior storefront, the transition from public to restricted space at lobbies and access control checkpoints, and back-of-house openings such as rear service doors, loading docks and small vision lites that can be exploited in smash-and-reach attacks.
What Should Architects and Specifiers Consider?
- Specify the UL 752 level for the complete assembly, not for the glazing alone. Bullet resistance is a system property, and the frame must be rated as well.
- Confirm nominal thickness and weight with Armortex. Both vary by makeup and configuration and are not fixed by the UL level alone.
- Establish whether no spall or low spall performance is required on the protected side.
- Match interior and exterior openings to separate criteria rather than applying a single level facility-wide.
- Account for framing material. Steel and metal alloys are typical for bullet resistant windows but introduce ricochet as a consideration.
- Coordinate voice transmission, speak-thru units, gun ports and pass-through transaction equipment into the assembly at design stage.
- Assign installation scope explicitly. Armortex is a material supplier and does not provide installation services, though it can assist in locating a contractor in your region.
- Require installation by competent and experienced installers per GANA guidelines. No certification is required; Armortex products are designed to be installed by anyone with skills and knowledge consistent with competent and experienced installers, often those with general construction experience.
Armortex maintains a BIM library through BIMsmith with Revit families for fiberglass composite panels, glass and containment glazing, fixed and transaction windows, pass-through transaction equipment, speakers, gun ports, gun lockers and man traps. Design professionals seeking background on protection levels and specification practice can take the Ron Blank & Associates online course.
Why Choose Armortex?
Armortex has been manufacturing bullet, blast and forced entry resistant products for more than thirty years, with over forty years of experience designing physical security products, and operates under an ISO 9001 quality management system. It is a single-source supplier for doors, windows, wall panels and related building fortification products.
Armortex is a custom manufacturer, designing and fabricating to project requirements rather than fitting openings to catalog parts. Fiberglass composite panels are manufactured from woven roving produced in-house rather than sourced externally, allowing material consistency to be controlled before lamination begins. In-house fabrication capability includes CNC waterjet and fiber optic laser cutting. The product line spans glazing, fixed and transaction windows, wood and hollow metal doors, aluminum storefront systems, fiberglass composite panels, transaction drawers, package receivers, deal trays, speakers, gun ports, gun lockers and man traps.
Frequently Asked Questions
Does security window film stop bullets?
No. Security window film does not stop bullets. Typical film thickness is 3 to 8 mils, compared with ¾ in. to 4 in. for bullet resistant glazing. Film can reduce spall and mitigate injuries from breakage, but stopping projectiles requires rated bullet resistant glazing.
Is bulletproof window film real?
If a film cannot meet a UL 752 ballistic standard, it is not truly bulletproof, regardless of how it is marketed. Adding thickness does not change this. Even relatively thick film remains thin compared with ballistic glazing and cannot reliably stop projectiles.
When is security window film appropriate?
Film is appropriate for mitigating glass injuries from accidental impacts and low-level vandalism, and for reducing spall and resisting entry from thrown objects and some blunt force attacks. It can delay forced entry. These are legitimate objectives distinct from ballistic protection.
When is true bullet resistant glazing required?
Rated glazing is required when the security requirement is to meet a specific bullet resistant standard such as UL 752 — protection for cashiers, courts, secure facilities and critical control rooms — and where the liability or risk profile requires certified protection against specified firearms and calibers.
Does the frame need to be bullet resistant too?
Yes. Bullet resistance is a system property, and the frame must be rated as well. If the security situation requires protection from gunfire, the only option is real bullet resistant glass, acrylic or polycarbonate installed in a bullet resistant frame.
How thick is Armortex bullet resistant glazing?
Bullet resistant glazing generally runs ¾ in. to 4 in. Nominal thickness and weight vary by makeup and UL level, so both should be confirmed with Armortex for the specific configuration rather than assumed from a drawing dimension or a level number.
How is bullet resistant glazing installed?
Installation should be performed by competent and experienced installers per GANA guidelines. No certification is required. Armortex products are designed to be installed by anyone with skills and knowledge consistent with competent and experienced installers, often those with general construction experience.
Conclusion
Security window film does not stop bullets. It retains broken glass, reduces spall, limits injury from accidental impact and vandalism, and delays forced entry from thrown objects and blunt force — all useful outcomes, and correctly specified on many openings. But at 3 to 8 mils against ¾ in. to 4 in. of rated glazing, film is a different category of product. Where the requirement is certified protection against specified firearms and calibers, the answer is bullet resistant glazing in a bullet resistant frame. Armortex manufactures that glazing at UL 752 Levels 1 through 10.