I am not real sure where to post this, but I had a question on this that came up at work. Is there a way to tell if glass is bulletproof or not? It looks similar to some that a friend of mine installed at his gas station after a couple of robberies and he says it isn’t bulletproof. My supervisor says it is and I was just hoping to confirm. I guess I could call the company and ask? I would understand “bulletproof” to be ammo dependent. This is the markings on the glass:
Yes, that didn’t go over very well. He was pretty insistent that it was, but I’m not an expert. I felt considering I would most likely be there in the event it would be needed, and not him I thought I would do some independent research.
We have glass in the shop I work in that says tempered safety glass too. It’s definitely not bullet proof. One of the guys got too excited with an impact and let the bolt go flying and it hit the window. It went straight through. The pieces of glass it broke looked like shattered auto glass (little pea sized nuggets)
It says safety glass because when tempered glass breaks it shatters and doesn’t hurt anyone. How thick is it? “Bulletproof” is usually very thick and a lot of panes of glass connected by inter layers.
ETA: most old style windows in houses, etc are annealed or plate glass, that breaks in big shards and can fall and cut people really badly (I’ve seen it happen) tempered is just harder, which makes it break the way it does.
Interesting. Looking at the picture again, it looks like its 1/4" or so. Either way, I doubt it is bulletproof. The manufacturer is required to put that information on the bug mostly so inspectors can see that the required glass is used.
I think you may be right. When I zoom in on the writing I think it says 1/4". There is a pretty big groove it sets in that has a gasket on each side and I was thinking of that when I was estimating the width. If it’s only 1/4" it won’t stop anything I wouldn’t think.
BR Glass will have several layers fused together by some sort of sheet between the layers of glass. Typically you will see 2 or 3 layers of nominal 1/4" glass (actually 6mm since glass is manuf. in metric)
A more common practice now is the use of policarbonite. It will usually be 1 or 1.25" thick and is more clear than BR glass because it does not have multiple layers. The frame also has to be UL tested for BR as the whole assembly has to work, not just one component. You can tell if you see the UL label on the frame or in the corner of the glass. Just like a UL approved light fixture or receptacle, it has to have the UL symbol along with the level of protection.
I’ve done several of these in banks in not so nice neighborhoods, typically we even did package receivers through the BR barrier all made out of 1" thick policarbonate.
This question might be a little off the wall, but it sounds like several of you have experience with commercial glass. I was sitting in a fast food restaurant a couple weeks ago with my infant daughter and was wondering how much force it would take to break one of those large, floor to ceiling windows in those places. I had the unpleasant thought of being trapped in a back corner of the restaurant in a fire, or worse case, an active shooter situation, and I was wondering if I could throw a chair through the window, or more likely break it by swinging a chair, if I had to make a quick exit.
Sorry for taking this off topic, but the question has been running through my head. Thanks!
All the HMMWVs or MRAPs ive ever been in, the BR glass was always several panes thick, with plastic layers in between each layer/ on the outside and front. My understanding is that the multiple layers of glass with the plastic layers catches the bullets, deflects if hit at an angle or with smaller munitions just chips away at the glass. But if you shoot them enough times they will be destroyed.
So usually BR glass is pretty dang thick, and heavy.
Bullet-resistant, not Bullet-proof. Even MRAP’s windows (which are multiple layers and at least 1.5 in thick, will only stand up so long to certain calibers…might deflect first or second rounds, but 3rd/4th not so likely (don’t know the exact specs). What you see in commercial applications isn’t nearly that strong, and it’s only there to stop (maybe) the first round from handgun calibers. Most all of it is polycarbonate sheet (we sell it); and to stop a sizeable handgun round minimum thickness is an inch or more. That stuff is HUNDREDS of dollars a square foot, which is why you won’t see it in commercial applications much (as it’s EXPENSIVE). That stuff in most gas stations will only last maybe one round, and the idea is that it’s JUST ENOUGH to give the guy behind it a chance to seek cover…