The term safe is very general. The generic term safe is described as “a metal container usually having a lock, used for storing valuables.” Safes can be more accurately defined by functional category and rating. Knowing these terms will help you to know what you’re buying.

Functional Categories

Functional categories are a combination of physical description and access capabilities. These terms are general enough that all safe retailers will know what you’re talking about:

  • wall safes – safes design specifically for in wall mounting
  • floor safes – safes designed to be embedded within a floor
  • chests – safes designed to be stand-alone on the floor
  • depositories – safes designed with hopper or slot for easy deposit of valuables without access to contents.
  • vaults – safes large enough to have walk-in access.

Underwriters’ Laboratories (UL)

UL is a non-profit, non-bias agency that tests and rates the safety and performance of consumer products. Safes that have earned specific UL ratings will carry a UL label which designates the product’s security and fire-protection ratings.

Net Working Time

This is the UL term for testing time which is spent trying to break into a safe using tools such as diamond grinding wheels, high-speed drills with pressure applying devices, or common hand tools such as hammers, chisels, saws, and carbide-tip drills. If a safe has been rated with a 30-minute net working time, (TL30), the rating certifies that the safe successfully withstood a full 30 minutes of attack time with a range of tools. There are over fifty different types of attacks that can be used to gain entrance into the safe. Usually they will try only 2 or 3 based on what they know about the product, and they know a lot.

Impact test

The UL impact test calls for the safe to be heated to 1550 degrees for 30 minutes (1638 degrees for a 2-hour fire rated safe) then dropped onto concrete rubble from a height of 30 feet. The safe is then turned upside down and reheated for another 30 minutes (45 minutes for a 2-hour fire rated safe). During this process, it must maintain its integrity and protect all contents in order to pass the UL impact test.

B-Rate Safes

This is a catchall rating for essentially any box with a lock on it. The safe industry had an unwritten standard of ¼ inch body, ½ inch door. As steel prices (and shipping costs) increased manufacturers tried many things to reduce their costs. No tests are given to provide this rating. When buying a B-rate safe, look at things such as lock work, hard plates, and relocks.

C-Rate Safes

This is defined as a ½ inch thick steel box with a 1-inch thick door and a lock. As before No tests are given to provide this rating. Look at the lock work, relocks and other features when making your decision.


Since the general definition of a safe could apply to a tackle box or a file cabinet, the insurance industry set certain standards to qualify as a ‘rated” safe. This designation assures the consumer that such a safe can be expected to minimize losses resulting from fire or burglary (depending upon rating) and is therefore considered when establishing insurance rates.

A “burglary rated” safe, properly constructed, will have for a minimum, a 1 inch steel plate body and a minimum 1 inch steel plate door with combination lock. Safes without this rating cannot be expected to offer any real protection from the aggressive burglar.

Burglary Ratings

Theft resistant – This rating means the safe provides a combination lock and minimal theft protection.

Residential Security Container rating (RSC) – This UL rating is based on testing conducted for a net working time of five minutes, on all sides, with a range of tools.

TL-15 rating – The TL-15 rating means the safe has been tested for a net working time of 15 minutes using high speed drills, saws and other sophisticated penetrating equipment. Safes given a U.L. TL-15 rating have all passed standardized tests defined in UL Standard 687 using the same tools and usually the same group of testing engineers. I have personally worked with the same 5 people for 15 years. The label requires that the safe be constructed of 1-inch solid steel or equivalent.

TL-30 rating – A product carrying the TL-30 security label has been tested for a net working time of 30 minutes with the same types of tools mentioned above. These tests are essentially the same as the TL-15 tests except for, you guessed it, the net working time. They get 30 minutes and a few more tools to help them gain entrance. Keep in mind these engineers have the manufacturing blue prints and can disassemble the safe being tested before the test begins to see how it works. They know their stuff.

TL-30 x 6 – The TL-30 (30-minute) test is conducted on all six (6) sides of the safe.

TRTL-30 – The TRTL rating designates a safe which successfully resisted 30 minutes of net working time with a torch and a range of tools which might include high speed drills and saws with carbide bits, pry bars, and other impact devices.

Fire Ratings

Explosion hazard test – All UL fire-rated safes must undergo this test, during which the unit is inserted into a pre-heated 2000 degree oven. If the safe is not constructed properly, the rapid heating will likely cause an explosion.

Class 350 1/2-hour fire rating – During this test, the safe is heated for one-half hour to reach an exterior temperature of 1550 degrees. Because paper will begin to char at approximately 400 degrees, the unit being tested must maintain an interior temperature of less than 350 degrees during heat-up and cool-down testing in order to earn its rating.

Class 350 1-hour fire rating – To earn this rating, the safe is heated for one hour to reach an exterior temperature of 1550 degrees, then put through the cool-down test. During this time the safe must maintain an interior temperature of less than 350 degrees.

Cool-down test – This procedure is a key part of UL’s fire testing procedures. After a one or two-hour fire rating test, the safe is left in the oven for cool-down time with the heat turned off. Because of the intensive heat of one- and two-hour tests, the temperature inside the safe will continue to rise for up to one hour after the oven is turned off. To pass UL testing, the safe’s interior temperature may not exceed 350 degrees at any time during heat-up or cool-down procedures.

Class 350 1-hour fire & impact label – The safe has passed both UL impact testing and Class 350 1-hour fire testing (see above).

Class 350 2-hour fire rating – The safe is heated for two hours to reach an exterior temperature of 1550 degrees and must maintain an interior temperature of less than 350 degrees to earn this rating. Class 350 2-hour rating and impact label – The safe has passed both UL impact testing and Class 350 2-hour fire testing (see above).

Questions regarding our safes or installation services? Give us a call at 561-795-6251 today to get started protecting your valuables with the security of a safe or vault!