Security ConsiderationsNo safe is impossible to open if there are the correct tools and enough time available. Therefore it is important to hide it from plain view and keep it a secret from as many people as possible. This way a potential criminal will overlook it or at least will not have the right tools prepared. Consider this the first level of security considerations. If you have kids – from my own experience you can not hide it from them. However you could educate them, so they do not share this knowledge at school or kindergarten.
A vault should not be visible to random visitors in your home. Also avoid a possibility to see it through a window. A closet or laundry room are popular for those reasons.
Consider the wall and floor material. It must be possible to securely mount a safe and to make sure the floor can hold the relatively large weight on a small area. And do not forget hidden plumbing and electrical wiring within the walls.
Solid materialChoose a safe with thick solid steel door and walls. It should be at minimum a 1/2″ thick door and a 1/4″ solid steel body. Do not trust manufacturers which do not state these values. You can also use a weight value as a hint, because steel is much heavier than cheap sheet metal. The material plays a major security role.
Safe lock UL approval
Consider only locks with UL approval – minimum Group 2. If you buy a vault with unapproved lock, it is very likely it was made in China. Such locks are undependable you are going to have troubles with them sooner or later.
Check the metal used to secure the locking bolts inside the door. Even if the bolts seems to be solid, it is useless in case of poor internal mechanism. Bolts ride on carrier rails inside the door and it is important that these rails are solid as well. If you have an opportunity during shopping, ask for a removal of the inner door panel and take a look inside.
Re-lockersHigher quality products increase the security with re-lockers which keep the door locked in case of a break-in. Re-locker pins are activated during an attack and it is very difficult to retract them after.
The fire protection is usually achieved by inserting a sheetrock in the safe wall. Keep in mind that the contents can not be protected given enough time and a high temperature. Currently there is no standard test or certification for this purpose, however you should search for a resistance to 1200 degrees for at least 60 minutes.