Problems with buying used safes include trouble with the locking mechanism and missing or damaged insulation. Buyers can avoid these problems and purchase a used safe at about half the price of a new one by selecting a used safe from a reputable company that refurbishes the units before selling them.

Whether new or used, safes sometimes give owners a false sense of security. Some gun safes are made of very thin metal and feature a lock that is easy to pry open with a screwdriver. Fire safes are also very easy to open with a few tools.

Most safes labeled "fireproof" are designed for the protection of paper documents or money for the rated number of hours. Paper starts to char at 451 degrees Fahrenheit, but electronic media, such as compact disks and computer drives suffer damage at much lower temperatures. Consumers should not depend on fireproof safes to protect important data or irreplaceable digital photographs, but should back up the material in other ways.

Floor safes provide excellent security, as they are buried in the concrete floor that surrounds them; however, they offer little protection because the door has no insulation. A better choice is a freestanding safe that uses several bolts to hold it in place.