How Are Safes Constructed?

Body

• The body of a safe is often made out of a single sheet of metal folded and then welded together along the joints. The thicker the steel, the more damage the safe can take. Sturdy Safe says the lower the gauge, the thicker the steel: 7-gauge walls are thicker than 12-gauge. Hinges are made to hold the safe door, which contains the locking mechanism; doors are usually made with a hole, then the lock is installed later.

Fireproofing

• Manufacturers fireproof a safe by lining it with fireproof material, or placing a layer of fireproofing between the wall and an interior steel plate. Depending on the quality of the safe, the material could be sheetrock, felt, fire-resistant ceramic wool or glass blankets, according to Sturdy Safe. The best insulating material is also heat resistant, otherwise the heat of a fire could destroy the contents, even if flames don't penetrate the safe. It's also possible to fit safes with an airtight door seal that will keep out the heated air.

Locks

• A safe can be fitted with a simple combination lock or something more advanced, such as an electronic keypad or even a biometric lock that responds to fingerprints, for example. When the lock is correctly opened, it slides back the bolts holding the door in place.

Relockers

• Many safe doors have relockers installed to make it harder to force them. Value Safes says a relocker usually has a spring-loaded bolt, which reacts to the impact of drills, hammers or crowbars on the safe. The bolt then adds its strength to the rest of the lock, keep burglars from opening the door.

Bank Vault

• Bank vaults are built differently from smaller safes and are custom designed for each bank, according to Made How. They're formed from steel-reinforced concrete: Walls are molded from concrete with steel rods placed inside to reinforce the concrete. The wall panels are taken to the bank and then welded together on site.