North Carolina Locksmith Practice Exam

Which UL rating is given to a mechanical combination lock able to withstand 20 man-hours of expert manipulation?

1. Group 1

2. Group 1R

3. Group 2

4. Group 2M

The correct answer is: Group 1

The rating of a mechanical combination lock that can withstand 20 man-hours of expert manipulation is classified as Group 1. This designation indicates that the lock has been rigorously tested for its resistance to manipulation and has proven to require significant time and expertise to bypass. Locks with a Group 1 rating are often recognized for their high-security features, making them suitable for applications where enhanced protection is paramount. They typically employ advanced design principles that make them more complex and difficult to manipulate compared to other groups. In contrast, other groups represent varying levels of security and manipulation resistance. For instance, Group 1R locks are slightly less robust due to their ability to withstand fewer hours of manipulation. Groups 2 and 2M indicate lower levels of protection, with Group 2 locks providing detections from manipulation for a shorter time frame than Group 1 and having different testing criteria. Understanding these distinctions helps locksmiths and security professionals make informed decisions about which locks provide the required level of security for specific applications.