TL;DR:
- Armortex® bullet-resistant fiberglass wall panels are available in UL 752 Levels 1 through 8, covering threats that range from 9mm handgun fire to 7.62mm military rifle rounds.
- Each level corresponds to a specific tested ammunition type, shot count, panel thickness, and weight per square foot.
- All panels are manufactured from woven roving ballistic-grade fiberglass, compressed with thermoset resin, and fire-rated to ASTM E119-00a.
- Selecting the correct level depends on the threat environment, not just convention — and the right specification decision happens during early design, not at bid time.
When architects and security consultants specify bullet-resistant wall panels, the first question that comes up is always some version of “what level do I need?” That question sounds simple. It is not. Behind it sits a cascade of decisions about threat environment, occupancy type, structural loading, wall assembly coordination, and budget — and the answer lives somewhere in that intersection, not on a single line of a product sheet.
Underwriters Laboratories Standard 752 (UL 752) is the testing and classification framework that makes meaningful comparison between products possible. Every level represents a specific threat scenario, tested to a defined ammunition type, grain weight, velocity, and shot count. A panel that passes UL 752 Level 3 has withstood three shots of .44 Magnum at 1,350 feet per second. A panel that passes Level 8 has withstood five shots of 7.62mm military rifle ammunition at 2,750 feet per second. The difference between those two scenarios is not a matter of degree. It is a different threat environment entirely, and it calls for a different panel.
This article explains what UL 752 levels are available for architectural bullet-resistant fiberglass wall panels, what the testing criteria mean in practice, and how manufacturers like Armortex® translate those standards into products that can be specified, fabricated, and installed in real buildings.
Table of Contents
- What UL 752 actually measures
- The full level range: Levels 1 through 8
- How the panels are manufactured
- Physical properties and panel dimensions
- Matching the level to the building type
- Installation considerations for wall assemblies
- Compliance, approvals, and fire rating
- Frequently asked questions
What UL 752 actually measures
UL 752 is the Standard for Bullet Resisting Equipment published by Underwriters Laboratories. It establishes performance requirements for materials and assemblies intended to resist penetration from ballistic projectiles. The standard defines eight protection levels, each tied to a specific weapon caliber, bullet type, bullet weight in grains, muzzle velocity in feet per second, and number of test shots. Passing a given level means the panel did not allow projectile penetration under those exact conditions.
This is a critical distinction for architects specifying security products: the UL 752 level describes the minimum threat the panel has been tested to withstand. It does not describe what the panel looks like after the test, it does not describe how the panel integrates with a wall framing system, and it does not automatically determine whether a higher or lower level is appropriate for a given project. Those are design and engineering decisions that happen above the product level.
What the standard gives the design team is a common technical language. When a courthouse security consultant writes “UL 752 Level 3” on a specification, every manufacturer, contractor, and authority having jurisdiction understands exactly what that means — which ammunition, how many shots, what velocity. That precision is what makes UL 752 the dominant classification framework for architectural bullet-resistant products in the United States.
The full level range: Levels 1 through 8
Armortex® manufactures bullet-resistant fiberglass panels across the full UL 752 range, from Level 1 through Level 8. Each level is a distinct product with its own thickness, weight, and test criteria. The table below summarizes all eight levels based on published Armortex product data.
| UL 752 Level | Armortex Model | Nominal Thickness | Nominal Weight | Ammunition Tested | Shots |
|---|---|---|---|---|---|
| Level 1 | O.F. 100 | 1/4″ | 2.9 lbs/ft² | 9mm FMJ, 124 gr, 1,175 fps | 3 |
| Level 2 | O.F. 200 | 3/8″ | 4.1 lbs/ft² | .357 Magnum jacketed soft point, 158 gr, 1,250 fps | 3 |
| Level 3 | O.F. 300 | 1/2″ | 5.25 lbs/ft² | .44 Magnum lead semi-wadcutter, 240 gr, 1,350 fps | 3 |
| Level 4 | O.F. 400 | 1 3/16″ | 13.7 lbs/ft² | .30 caliber rifle, soft point, 180 gr, 2,540 fps | 1 |
| Level 5 | O.F. 500 | 1 3/8″ | 15 lbs/ft² | 7.62mm rifle FMJ military ball, 150 gr, 2,750 fps | 1 |
| Level 6 | O.F. 600 | See data sheet | See data sheet | See data sheet | — |
| Level 7 | O.F. 700 | 1 3/16″ | 12.2 lbs/ft² | 5.56mm rifle FMJ, 55 gr, 3,080 fps | 5 |
| Level 8 | O.F. 800 | 1 3/8″ | 16 lbs/ft² | 7.62mm rifle FMJ military ball, 150 gr, 2,750 fps | 5 |
Source: Armortex® product data sheets. Level 6 data sheet available directly from Armortex.
Several things are worth noting in this table. First, the jump between Levels 3 and 4 is substantial — not just in thickness and weight, but in the nature of the threat. Levels 1 through 3 address handgun calibers. Level 4 crosses into rifle territory. That transition drives a significant increase in panel mass: the Level 3 panel weighs 5.25 pounds per square foot, while the Level 4 panel weighs 13.7 pounds per square foot. That difference has structural and installation implications that must be resolved during design, not during construction.
Second, shot count matters. Levels 4 and 5 are tested with a single shot, while Levels 7 and 8 require the panel to withstand five shots of high-velocity rifle fire. A panel rated for multiple shots at a given caliber represents a meaningfully higher level of sustained performance than one tested for a single impact.
Level 1: 9mm Handgun
The O.F. 100 panel at 1/4″ thickness addresses the most commonly specified threat scenario in commercial construction. A 9mm full metal copper jacket round at 1,175 fps represents the threat profile appropriate for retail environments, check-cashing facilities, bank teller lines, and school reception areas. At 2.9 pounds per square foot, the Level 1 panel is the lightest in the Armortex lineup, which simplifies installation and reduces structural demands on the wall framing system.
Level 2: .357 Magnum
The O.F. 200 at 3/8″ thickness steps up to a .357 Magnum jacketed soft point at 1,250 fps. This level is appropriate where the threat environment includes higher-caliber handguns — common in specifications for police station lobby areas, government office reception areas, and credit union transaction windows. The panel weighs 4.1 pounds per square foot.
Level 3: .44 Magnum
At 1/2″ thickness, the O.F. 300 addresses .44 Magnum semi-wadcutter ammunition at 1,350 fps, tested with three shots. This is one of the most frequently specified levels for courthouse and criminal justice facilities. The .44 Magnum is a high-energy handgun round, and three-shot resistance provides meaningful assurance against sustained attack scenarios.
Level 4: .30 Caliber Rifle
The O.F. 400 at 1 3/16″ is where the Armortex panel lineup enters rifle-rated territory. A .30 caliber soft point at 2,540 fps represents a hunting rifle profile. This level is appropriate for military facilities, certain government installations, and high-value asset protection environments where the threat model includes long-gun scenarios. At 13.7 pounds per square foot, the wall assembly engineering implications become significant: framing, attachment, and load path all require coordination.
Level 5: 7.62mm Rifle (Single Shot)
The O.F. 500 at 1 3/8″ addresses one of the most serious rifle threats in the UL 752 framework — 7.62mm military ball at 2,750 fps. The single-shot test distinguishes Level 5 from Level 8, which uses the same ammunition but requires five shots. Level 5 is specified in some government and military applications where the threat assessment establishes a lower probability of sustained rifle fire.
Level 7: 5.56mm Rifle (Five Shots)
The O.F. 700 at 1 3/16″ is tested against 5.56mm rifle fire — the caliber associated with M16 and AR-15 pattern weapons — at 3,080 fps, with five shots required. This is a demanding performance threshold. The five-shot requirement is particularly relevant in active-shooter threat scenarios where multiple rounds from a single weapon are the operative concern. Despite addressing a higher-velocity round than Level 5, the Level 7 panel is slightly lighter at 12.2 pounds per square foot, reflecting the lighter 55-grain projectile.
Level 8: 7.62mm Rifle (Five Shots)
The O.F. 800 at 1 3/8″ represents the highest level in the Armortex fiberglass panel lineup. Five shots of 7.62mm military ball at 2,750 fps requires the panel to retain structural integrity and prevent penetration under sustained heavy-caliber rifle fire. At 16 pounds per square foot, this is the heaviest panel in the product line. Applications include military facilities, federal law enforcement, and high-security detention environments.
How the panels are manufactured
Understanding what is inside a bullet-resistant fiberglass panel matters for specification, not just for curiosity. The Armortex manufacturing process begins with woven roving ballistic-grade fiberglass that is produced in-house. That cloth is mechanically injected with a thermoset polyester resin and then compressed into flat rigid sheets using a hydraulic hot press.
That process — in-house weaving, controlled resin injection, hydraulic pressing — is where the ballistic performance is actually determined. The hot pressing process allows for proper delamination control and reliable projectile retention. A panel that is improperly pressed will not arrest a projectile consistently; it will allow delamination to propagate in a way that compromises the capture mechanism. This is why manufacturing process control, not just material selection, is the basis for consistent ballistic performance.
The result is a composite panel that looks like a standard construction sheet material but behaves as a precision-engineered ballistic barrier. All Armortex fiberglass panels are UL-compliant and have been approved by the U.S. Marshal Service and the General Services Administration, as well as other government agencies.
Physical properties and panel dimensions
All Armortex bullet-resistant fiberglass panels are available in the following sheet sizes:
- 3′ × 8′, 4′ × 8′
- 3′ × 9′, 4′ × 9′
- 3′ × 10′, 4′ × 10′
Edges are square. The primary material is composite fiberglass. Application is interior — these panels are designed as interior wall assemblies, not exterior cladding.
The weight range across the full product line runs from 2.5 pounds per square foot at the low end to 14.5 pounds per square foot at the mid-range, with the Level 8 panel reaching 16 pounds per square foot. For a wall assembly that covers 100 square feet, the Level 8 panel contributes approximately 1,600 pounds in panel weight alone. That load must be accounted for in the structural framing, connection details, and floor loading calculations.
Armortex also maintains a BIM/Revit library and provides fabrication and cutting instructions, a ballistic performance chart, and fire test documentation as part of their standard technical package. CNC waterjet and fiber optic laser cutting capabilities are available for custom panel shapes and penetrations.
Matching the level to the building type
The decision about which UL 752 level to specify is a threat-assessment exercise, not a product selection exercise. The product selection follows the threat assessment. With that sequence in mind, the following guidance reflects the application uses listed in Armortex product documentation:
Levels 1–3 (handgun calibers) are appropriate for commercial and retail environments, banks, credit unions, check-cashing facilities, school reception and administrative areas, and office lobbies where the threat profile centers on handgun-caliber weapons. Level 1 handles the 9mm threat that appears most frequently in security assessments for high-transaction commercial environments. Levels 2 and 3 address higher-energy handgun threats for facilities with elevated risk profiles.
Level 3 is particularly common in courthouse and detention facility specifications, where the .44 Magnum threat model and three-shot resistance requirement align with the security standards applied to these building types.
Levels 4 and 5 (rifle calibers, single shot) begin to appear in government, military, and law enforcement facility specifications. Police station public counter areas, government administrative buildings in elevated threat environments, and perimeter security rooms may warrant Level 4 or 5 depending on the formal threat assessment.
Levels 7 and 8 (rifle calibers, five shots) are appropriate for military facilities, federal law enforcement, high-security detention, and safe room construction where the threat model includes sustained rifle fire. The five-shot test requirement makes these levels the most demanding in the UL 752 framework and the most demanding to engineer into a wall assembly.
It is worth noting that the same facility type can appropriately require different levels in different zones. A courthouse may call for Level 3 at the public reception counter, Level 5 in the holding area walls, and Level 1 in the judge’s chambers — because the threat profile is not uniform across the building. Applying a single level to an entire project without zone-by-zone analysis typically results in either underprotection in critical areas or expensive overspecification in lower-risk zones.
Installation considerations for wall assemblies
Bullet-resistant fiberglass panels install similarly to other sheet materials in wood or metal stud wall assemblies, but several considerations require attention during design.
Armortex recommends cutting the panels with a RemGrit® “Grit Edge” saw blade using ordinary carpentry tools. Self-tapping drywall screws are used for installation. Pre-drilling is recommended for panels at 1 3/16″ thickness and above — the heavier rifle-rated panels require this step. At seams, 4″ overlap strips (battens) are recommended to maintain ballistic continuity across joints.
The batten requirement at seams is the single most important installation detail in a bullet-resistant wall assembly. A panel joint without a batten is a potential penetration path. In projects where seam locations are visible from the attack side, the design team should coordinate panel layout to minimize exposed joints, and specify batten installation in the construction documents explicitly — not as an option or a contractor-selected detail.
The weight difference between levels also affects installation planning. The heavier rifle-rated panels at Levels 4 through 8 require more robust attachment and cannot be handled the same way as the lighter handgun-rated panels. Fastener spacing, backing framing, and lifting and placement methods all need to be addressed in the installation documentation.
Compliance, approvals, and fire rating
All Armortex bullet-resistant fiberglass panels are tested to the Underwriters Laboratories UL 752 11th Edition Standard for Bullet Resisting Equipment. The panels are also one-hour fire rated to ASTM E119-00a, the standard test method for fire tests of building construction and materials.
The fire rating is significant for building code compliance. Interior wall assemblies in most occupancies are subject to fire-resistance requirements under the International Building Code, and bullet-resistant panels that carry an ASTM E119-00a rating can satisfy those requirements without requiring a separate fire-rated assembly on top of the security assembly. This simplifies the wall section and avoids the coordination problems that arise when fire protection and ballistic protection systems are specified and installed independently.
The panels are produced under an ISO 9001 quality management system and have been approved by the U.S. Marshal Service, the General Services Administration, and various other government agencies. For federal, GSA-funded, or U.S. Marshal Service projects, these approvals represent pre-vetted compliance that simplifies the specification and procurement process.
Frequently asked questions
What UL 752 levels does Armortex make for wall panels? Armortex manufactures bullet-resistant fiberglass wall panels in UL 752 Levels 1 through 8. Each level is a distinct product with its own thickness, weight, ammunition test specification, and shot count requirement.
What is the difference between UL 752 Level 3 and Level 4? Level 3 addresses .44 Magnum handgun ammunition (3 shots at 1,350 fps). Level 4 addresses .30 caliber rifle ammunition (1 shot at 2,540 fps). The jump between them represents a transition from handgun to rifle threat calibers, with a corresponding increase in panel thickness from 1/2″ to 1 3/16″ and a weight increase from 5.25 to 13.7 pounds per square foot.
Are Armortex bullet-resistant panels fire rated? Yes. All Armortex fiberglass panels carry a one-hour fire rating tested to ASTM E119-00a, the standard for fire tests of building construction and materials.
What applications are Armortex bullet-resistant panels suitable for? Per Armortex product documentation, applications include commercial and residential buildings, government facilities, military installations, banks, credit unions, retail, check cashing, prisons, courthouses, police stations, safe rooms, schools, public safety facilities, and stadiums.
How are Armortex bullet-resistant fiberglass panels installed? The panels are cut with ordinary carpentry tools using a RemGrit® Grit Edge saw blade and attached with self-tapping drywall screws. Pre-drilling is required for panels 1 3/16″ and thicker. Armortex recommends 4″ overlap strips (battens) at all panel seams to maintain ballistic continuity.
What sizes are available? Armortex bullet-resistant fiberglass panels are available in widths of 3′ or 4′ and lengths of 8′, 9′, or 10′. All edges are square cut.
Are the panels approved for government projects? Yes. Armortex bullet-resistant fiberglass panels have been approved by the U.S. Marshal Service and the General Services Administration, as well as other government agencies.
Source: All product specifications, test data, and application information referenced in this article are drawn from published Armortex® product data sheets and the Armortex website at armortex.com. Contact Armortex directly at 1-800-880-8306 or info@armortex.com for project-specific technical support.