How to Compare Burglary & Fire Safe Ratings

Research construction ratings. According to Maximum Security Safes, construction ratings run from the letter "B" to "F," in ascending order of sturdiness. A "B" rating means the safe has steel doors less than one inch thick and walls less than half an inch thick. A "C" rating means it has steel doors at least one inch thick and walls at least half an inch thick. An "E" rating means it has steel doors at least one-and-a-half inches thick, and walls at least one inch thick. An "ER," "G" or "F" rating also requires a UL mark certifying its resistance to ever-increasing intensities of attack.

Research performance ratings. UL performance ratings measure how long a given safe can resist a safecracking attempt, and what kinds of attacks it can withstand. According to KL Security Enterprises, a residential security container (RSC) rating means the container has the ability to "withstand five full minutes of rigorous prying, drilling, punching, chiseling and tampering attacks by UL technicians."

A safe with a Burglary Classification TL-15 is a combination-locked safe that "successfully resisted entry for a net working time of 15 minutes when attacked with common hand tools, picking tools, mechanical or portable electric tools, grinding points, carbide drills and pressure-applying devices or mechanisms."

A safe with a Burglary Classification of TL-30, on the other hand, is a combination-locked safe that "successfully resisted entry for a net working time of 30 minutes when attacked with common hand tools, picking tools, mechanical or portable electric tools, grinding points, carbide drills and pressure-applying devices or mechanisms, abrasive cutting wheels and power saws."

Research fire ratings. UL uses many tests to determine fire safety: fire endurance, fire and impact (to determine if a heated safe can resist a multi-story fall of the kind that often happens in house fires) and an explosion test. Fire ratings on a safe are expressed by class and hour. The class refers to the maximum temperature allowed within the safe to qualify for a UL mark. 350 degrees is the limit for safes containing paper, 150 and 125 degrees are the interior temperature limit for safes meant to house various computer media. The hour designation, according to KL Security, is meant to indicate "how long the fire-resistant product was tested to withstand exposure to extreme temperature and still maintain a safe temperature/humidity level inside. The time lengths are half an hour, one hour, two hours, three hours and four hours. These times do not represent the total time of the tests, nor are they totally indicative of the amount of protection offered. One-hour-rated products offer more than 'one hour's worth of protection.'"