Bullet and Blast Resistant Door and Frame Assemblies

Bullet and Blast Resistant Door and Frame Assemblies

From military installations and government facilities to hospitals and office buildings, some locations demand an extra layer of safety. Bullet resistant doors are secure entryways comprised of ballistic-resistant core materials and veneered wood or hollow metal products. As a result, making them perfect for important facilities such as government buildings, army bases, banks, casinos, emergency and currency rooms.

Bullet resistant steel door and frame assemblies are subject to the criteria established in the document UL 752 Standard for Safety for Bullet-resisting Equipment. The UL 752 document is a standardized set of requirements associated with creating bullet resistant components such as doors, barriers and glass shielding. Ten distinct levels of bullet resistance are established within the UL 752 document, ranging from a small .38 mm handgun (Level 1) through to a .50 caliber, high powered, military assault rifle (Level 10).

AMBICO manufactures an extensive range of bullet-resistant steel and wood doors, as well as borrowed and sidelight applications. Our Bullet resistant steel and wood doors provide an exceptionally strong protective opening solution. Each door and subsequent component has undergone independent testing to ensure safety and security against ballistic threat. Our bullet resistant steel door and window assemblies protect against ballistic threats from UL 752 levels 1-10 while our bullet resistant wood door assemblies, available with a cross-banded wood face veneer with hardwood edges, protect from UL 752 levels 1-8. 

Blast Resistant Door and Frame Assemblies

Blast resistance is the ability of a material or structure to withstand pressure from an explosion. Since “blast-proof” would mean that the material is entirely immune to damage from any and every explosion, it is not a term that we use when discussing windows and doors. Instead, we use the term “blast-resistant.”

While it is not possible to completely prevent explosions, there are ways to minimize, or “mitigate,” the amount of damage done to the building and those inside of it. These bomb blast mitigation techniques can include incorporating blast resistance into building design, installing blast-resistant doors and windows, and creating standoff distance between the threat and the building when possible.

Windows and doors that are blast resistant are often designed to flex or “give” when subjected to a bomb blast. However, unlike bullet resistant windows and doors the performance of a blast resistant window and door can be affected by the building structure and how they are installed. The amount of structural damage (permanent deformation) after a blast affects the operability of the door, and whether or not the door and/or frame or their parts (including glass and hardware) become detached and present a debris hazard. With respect to a glazing system, the damage is defined by whether the glazing fractures, and if it presents a flying debris hazard. 

Table 1 below shows the ASTM F2927 response categories, which is a commonly specified Standard Test Method for Door Systems subject to airblast loading. The level of damage that would result from a projected blast event on a door assembly ranges from Category I (no damage) to Category IV (catastrophic failure). 

Table 1.

Response End Rotation Ductility Description
Category I 1.2 1 No permanent deformation, and the hardware of the door remains operable
Category II 2 3 Minor permanent deformation, but the door remains operable.
Category III 8 10 Major permanent deformation. However, the door hardware may be inoperable.
Category IV 12 20 Severe permanent deformation and door hardware will be inoperable.


Category 1 involves no permanent damage or deformation of the door. The door and hardware remain operable, and the door system has an end rotation that is not greater than 1.2 degrees and a maximum ductility ratio of 1. Category 2 is defined by the end rotation not being greater than 2 degrees and a maximum ductility ratio of 3, which indicates that there will be minor permanent deformation. However, the door will not jam into the frame and all hardware will remain operable. Categories 3 and 4 result in end rotations and ductility ratios that would deform the door permanently and the door would not be operable following a blast event.

Too many doors in the US government and military makes categories 1 and 2 unaffordable and category 3 their default and most suited option. On the contrary, the petrochemical industry installs blast resistant doors on manned rooms, which makes category 2 their default option, as they want the doors to remain operable in the event of an explosion. Depending on the application and their needs that the end rotation and ductility can vary.

Table 2 below shows the Standard Specification Levels for Glazing and Glazing Systems, ASTM F2912. The table indicates performance requirements of glazing or glazing subject to air blast loading and is used to determine blast capacity from a shock wave or explosion.

To know more about the above-mentioned test standards of Blast Resistant Door and Frame Assemblies visit:

ASTM F2912 Test Standard | Blast Resistant Door and Frame Assemblies

ASTM F2927 Test Standards | Blast Resistant Door and Frame Assemblies

AMBICO blast resistant steel doors and frames combine blast and air pressure resistance with the functionality of standard hollow metal products. Our hollow metal doors provide reliable protection against military-grade explosives in the event of extreme security threats. AMBICO has an extensive blast resistant door & frame product line that was developed specifically for UFC 4-010-01 projects. 

AMBICO teamed up with the University of Ottawa’s Hazard Mitigation and Disaster Management Research Centre to conduct an extensive research & development project involving over 55 shock tube tests, as per ASTM F-2927, of various blast door products in various configurations and sizes. Additional static pressure testing, as per ASTM F-2247, and finite element analyses were performed to develop software to verify blast door & frame performance for any charge weight, standoff, and level of protection scenario.

AMBICO’s engineering department has years of experience performing blast door & frame analysis for almost any imaginable charge weight, standoff, level of protection, and door & frame configuration.

Bulletproof: A Commonly Used Word that is Technically Wrong 

The biggest difference between the bullet proof and bullet-resistant is that one is often misused while the other is the real deal. The word bulletproof is in wide use across society, and even those of use in the protective glass industry use it as well for that very reason. From a technical perspective, when you start pairing the word bulletproof with glass, you’re venturing onto thin ice. Let us take, for example, a piece of glass built to withstand several rounds of ammunition from a small handgun. Is it bulletproof? Technically, no. A single round from a much more powerful gun and a larger-caliber bullet will likely penetrate it. In fact, although it should protect against three rounds of bullets from the small handgun, if you kept firing more rounds at the glass, it would eventually give in. 

The truth is, no matter how thick and strong you make a protective glass, there is always going to be a bigger gun with a bigger bullet that can get through it. The more accurate term for what people mean when they say bulletproof glass is bullet-resistant glass

Similarly, we do not say blast-proof, or explosion-proof, because we know that explosions are powerful forces. If the intensity of the explosion exceeds what the door/window is designed to resist, there is a strong possibility that it could fail. However, blast-resistant means the door/window can resist some type of hazardous penetration and minimize the amount of damage done to the building.

At AMBICO, we never sacrifice safety. We find it best to plan for what could happen and even go a step further. Click on the links below to know more about our Bullet and Blast Resistant Door and Frame Assemblies, 

Bullet Resistant Door and Frame Assemblies

Blast Resistant Door and Frame Assemblies

Contact us today to request a quote or learn more about these strong, resilient, and visually appealing products.


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