Select the security door to see several indicators

One of the first things to check is whether the door has an anti-theft rating. Under the new national standard, the previous three levels have been upgraded to four grades: A, B, C, and Ding. Grade A is the highest, followed by B, C, and Ding. Each level corresponds to different resistance times: Class A doors must withstand forced entry for at least 30 minutes, B for 15 minutes, C for 10 minutes, and Ding for 6 minutes. These ratings are usually marked with letters like J, Y, B, or D on the inner side of the door's hinge, about 1600 mm from the ground. If you don’t see this marking, it might just be a regular steel door, not a real security door.

Another important factor is the number of lock points. The new standard requires a minimum of 12, 10, 8, and 6 lock points for Grades A, B, C, and Ding respectively. While more lock points may seem better, it’s not always the case. In many cases, all these points are controlled by a single lock cylinder. Therefore, it's crucial to check the quality of the lock itself. China classifies locks into three grades: A, B, and Super B, with Super B being the most secure. Additionally, the main lock should be at least 16 mm long to provide better resistance against picking or forced entry.

The thickness of the steel plate is another essential indicator of a security door’s quality. According to the new standard, the door frame should be at least 2 mm thick, while the door body should be over 20 mm thick and weigh more than 40 kg. For specific grades, the steel thickness varies: A and B require 2 mm, C needs 1.8 mm, and D is 1.5 mm. In terms of materials, copper doors are the most durable and expensive, followed by stainless steel and aluminum alloy models.

To get a better understanding of the door’s internal structure, it’s a good idea to remove the peephole or doorbell box to inspect the inside. Look at the thickness of the steel panels, whether there is any filler material that offers fire resistance or sound insulation, and check if the front and back panels are properly connected without gaps. This will give you a clearer picture of the door’s overall build quality.

If you want to further enhance the security of your door, consider adding features like a tamper-proof cover for the lock or a reinforced peephole device. These small additions can significantly improve the door’s resistance to intrusion. Always make sure to verify the official certification and specifications before making a purchase to ensure you’re getting a genuine security door that meets safety standards.