To be fair to Sentry Safe, this product is designed to be resistant to fire. A better name for this product would be ‘fire resistant box’ instead of ‘fire safe’ but that’s what they call it for marketing reasons.
A hardened metal safe designed to be resistant to cutting can still be cut through, just not in seconds with a screamer saw (trade name for a metal cutting circular saw)
If you want truly secure, encase your metal box in concrete like John Wick. Access is difficult but security is high :)
> encase your metal box in concrete
FYI, most safes already have a decently thick concrete layer — that’s most of why safes are heavy! (Or, I guess you could say, adding a concrete layer is cheaper than making the steel thicker.)
But they also have a rubber or foam (often styrofoam in cheaper safes) layer, to “smooth out” the force from a sledgehammer, jackhammer, or just dropping the thing out the window.
And a layer of compressible wet(!) sand, to spread out the point stress from a hammer and chisel, impact gun, gunshot, or small explosive configured for concussive force. (The goal here is essentially to replicate the behavior of a bulletproof vest.)
Plus, they often contain a layer to bind and foul and dull (or even break) the teeth of drill bits and reciprocating/chain/band saws. This can be any number of things — low-melting-point plastics, recycled broken glass, etc — but look up “proteus” for a fun read.
If the safe’s designer is clever, just a few materials can serve several of these functions at once. But more is always better. Which is why good safes (and vaults) are so dang thick. It’s not to solve one problem really well; it’s to mitigate N problems acceptably well, for a frighteningly large value of N.
It's fun looking at the machinery of old fashioned bank vaults. Very impressive.
So carefully applied thermite to defeat all of them at once? Probably not directly down to drip into the valuables, but some tangent application.
Even not dripping directly on to the goods, there's not a lot of stuff that you would be interested in getting out of a safe, but you will still be interested in even after being exposed to thermite. The list is basically "precious metals" and not much more, though that is admittedly a valid entry on the list.
In an analog to the somewhat frequent observation on HN that if you don't care whether the code is correct I can make it run arbitrarily quickly, if you don't care if the contents of the safe survive there's a lot of high-energy ways to blast it to smithereens. This is generally not considered a problem to be solved with a safe, though. If you want to prevent "being blasted to smithereens" that you'll need a completely different approach.
so... if i were a suitably evil billionaire, would i be able to shop for a safe protected by a layer of compressed mustard gas, that is released upon attempted breaching?
This would be a Booby Trap and is illegal, so it's not worth it for that chance of going to prison no matter the value in the safe, if you are a billionaire. It would be hard to find someone willing to help you.
Is it still a booby trap if the safe displays a prominent warning, "CAUTION: EMITS DEADLY GAS WHEN DAMAGED"?
Depends on your lawyer.
The law is someone less picky about armed guards, though, so you may just want to pay some thugs to watch your safe.
Gandalf - “But men are better than gates, and no gate will endure against our Enemy if men desert it.”
That's too bad - life would be better if we had a few fewer criminals around.
Is it perhaps called after the movie Screemers ? Some of the combat robots had circular saws, but they used to to cut through people instead of locks.