Jim Richards | |
When people think about bulletproof materials, many still picture gleaming diamond plate, big steel panels, and scrap metal.
A lot of those ideas come from popular culture. How many times have you seen an action hero safely duck behind a car door, filling cabinet, or steel desk while the bad guys indiscriminately spray gunfire everywhere? (Spoiler alert: In real life, none of those things can stop even a single bullet from the smallest pocket pistol.)
But Hollywood isn’t entirely to blame.
Self-appointed security enthusiasts on social media and in online discussions about protecting homes from gunfire often focus on metal bookshelves, steel doors, or “lining the walls with steel.” We also see smaller consumer-facing regional companies promoting residential bulletproofing “solutions” that highlight steel doors, steel panels, and armored metal wall systems (even if that is only a very small part of what they handle).
All of this reinforces the erroneous idea that metal cladding is the best way to stop bullets. The truth is that steel and aluminum play an important role in bullet resistant barriers, but it isn't a flashy one, and it doesn’t rely on the same 20-gauge cold-rolled steel used on car doors and office furniture.
So what actually is the best bulletproof material? To effectively explain it, let’s start with the basics.
Ballistic Protection Levels
“Bulletproof” is a layperson’s word with no real meaning. People use it to describe everything from reliable engines to the newest fad diet.
When it comes to safety and security, barrier systems and their components are “bullet resistant”:
They’ve been tested in a recognized third-party laboratory against a widely accepted standard for bullet resistance, such as UL 752, the Standard for Bullet-Resisting Equipment.
During these tests, a sample of the bulletproof glass, steel, ballistic plate, or other materials is mounted as it would be for installation and shot a specific number of times at a specific distance, angle, and grouping using a specific caliber of bullet. If the material or component passes that test, it can be described as “ballistically rated” to a specific level, and you can rest assured it will perform as described.
For example, a “UL Level 3” bulletproof window has been tested against Level 3 of the UL 752 standard. It will stop at least three shots from a .44 Magnum pistol (or a similar number of most handgun rounds). Level 8 armor plate steel will stop a spray of five shots from a 7.62 tactical rifle, as well as most other rifle rounds. Broadly speaking, materials rated Levels 3 and below stop bullets fired from pistols, while those rated Levels 4 and above will effectively stop bullets from rifles or pistols.
Nothing in life is 100% “bulletproof,” and if you are told something is bullet resistant, you should ask about its ballistic rating. The answer should be straightforward, like “UL Level 3” or “NIJ III-A.”
If you’re unfamiliar with ballistic security, this can all seem daunting. We’ve put together a library of free resources to help you make good security choices. Our Ultimate Guide to Ballistic Security (and associated quick-reference ballistic security infographic ) are good places to start.
What Metals are Bulletproof?
This is the wrong question to ask. Almost any metal could stop a few bullets if the material is thick enough. But is that practical or cost effective?
The most commonly used metals in ballistic barrier systems are aluminum and steel, which are also the most common construction metals in general.
People talk about exotic metals like titanium, tungsten, aluminum-lithium alloy, and ceramic materials, debating weight versusvs strength versus density versus brittleness versusplastic deformation—but that is all just talk. In real ballistic barrier systems, we use steel for door panels, and both aluminum and steel for framing doors and bullet-resistant windows.
It is common practice to line walls to make them bullet resistant, but it is extremely unusual to use steel plates for that. In theory you could do this, but you would drive yourself nuts: Every attachment point and hole for a light switch, fixture, or outlet would need to be factory pre-drilled or laser cut in advance. Mounting drywall over those steel plates would be a nightmare, and you’d never hang a picture again.
Instead, we make walls bulletproof using composite materials like ballistic fiberglass. These can be lighter than high-hardness metal plates, are always easier to work with, and perform fantastically. Take this door for example:
That is a Level 3 steel door. It is rated to stop three shots from a .44 Magnum, but massively outperforms that rating, stopping more than 100 shots from a range of rifles and pistols without even a dimple on the protected side. That has little to do with the steel you see.
The bullets pass right through that, and are stopped by the fiberglass panel inside. This construction has the added benefit of trapping the bullet inside the door, reducing the chance that a ricochet will harm someone.
Steel as a Bulletproof Material
There are many kinds of steel, and despite what you see in movies, most of them won’t do a thing to stop a bullet.
That’s because most of the steel you see is cold-rolled steel, which is very precise and formable, but not intended to lend a lot of structural strength. Car doors, appliance panels, office furniture, and steel security doors are all made from cold-rolled steel between 0.03 and 0.05 inch thick. You’d need a piece of that steel to be closer to 0.25 inch thick—around the thickness of a pencil—to even hope to stop a bullet.
Even our bulletproof steel doors and frames—which are regularly made from thicker 16-gauge cold-rolled steel or stainless steel—won’t stop bullets on their own.
Bulletproof steel doors and frames don’t get their bullet resistance from the metal you see, but from their layered construction.
Bullet Resistant Armor Plate
When we use steel in a ballistic system, it is hardened “armor plate” steel like AR500 or AR550.
This steel is so hard that it doesn’t bend or dent when shot, even with high-caliber, high-speed rounds. Instead, the bullet typically shatters into dust or small fragments upon impact. Just 5/16th of an inch of this material can stop most bullets.
But no one ever sees that armor plate.
In general, steel doors and frames that are Level 3 or below (like the one in the video) are reinforced with fiberglass ballistic panels. Once you get to Level 4 protection, fiberglass becomes very thick (around 1.25 inches).
You could still use that in the door, but if we relied on fiberglass to bulletproof that door frame, it would start to look awkward around doorways.
By using armor plate, which is only about 1/4 or 5/16 of an inch thick, we can wrap the wall and maintain a slimmer, standard profile for the frame throat. At the highest security levels, like Level 7 and 8, the thickness of fiberglass begins to get extremely unwieldy for the door itself. At that point, armor plate is much easier to work with and makes for a more usable system.
Is Aluminum Bulletproof?
Many people are surprised to learn that aluminum can stop bullets, despite being less dense than steel. At TSS, we use aluminum for window frames, door frames, and stiles in storefront-style entryway systems. (In bulletproofing, an “aluminum door” refers to a ballistic glass door with a prominent aluminum frame. If someone needs a shiny metal door, they would probably go with stainless steel.)
We’ve designed our aluminum frames such that, because of their thickness and geometry, they can deflect handgun bullets without additional reinforcement, passing up to Level 3 testing. For Levels 4 through 8, our aluminum frames are designed with special slots that receive ballistic fiberglass inserts, providing ballistic protection inside the aluminum shell that tends to trap bullets, just like our doors.
Sometimes people like to bring up “transparent aluminum,” because of that old Star Trek movie.
When that movie came out, transparent aluminum was still sci-fi.
Today, transparent aluminum (technically a transparent aluminum-based ceramic, or “aluminum oxynitride,” sold under the brand name “ALON®”) is no longer fiction.
It is used in military vehicles and high-security windows to stop .50 caliber rounds. We’ve never seen it in the field, but it is indeed a reality.
TSS Specializes in Bullet Resistant Materials for Real-World Protection
There’s no “perfect” bulletproof metal.
No material can be made perfectly bulletproof, and no single material is perfect for every situation.
At TSS, we select materials based on threat level, aesthetics, budget, and usability.
Steel doors and frames are a great utilitarian choice.
Stainless steel looks great in many settings.
Aluminum framing is nearly an industry standard and blends into most buildings.
Ballistic fiberglass can make any room, service counter, podium, or door into a potential safe haven. Any of these solutions can work at any threat level.
In my experience, if someone is asking about what metals are bulletproof, they probably either need ballistic fiberglass for walls, are considering bullet resistant doors (here’s our guide to ballistic doors), or are just beginning to explore ballistic security for their organization or facility and aren’t quite sure where to start.
This is where our blog post about costs and pricing of a bulletproof system is helpful.
Over the last 20 years, TSS has created countless ballistic barriers and safe rooms across the country.
No matter your threat level, organization size, or building layout, our skilled team is ready to help you find a solution that protects your people and works with your budget.
Contact our ballistic security experts to learn more about designing your ideal bulletproof solution, or request a quote if you are ready to begin. Our team looks forward to helping you.
