2. Generally speaking, household grade D is enough (the price is less than RMB 1000, the front door leaf is 0.8MM, the rear door leaf is 0.6MM, the door frame is 1.5MM, and the technical violence is not less than 6 minutes). If the community is not safe, you can choose a better one. If you don't know much about security doors, if the economy allows, choose the doors of first-line brands (top ten brands), which will be guaranteed after sale.
3. Considering the living environment, choose the thickness of the door leaf, 5 cm, 7 cm and 9 cm. Theoretically, the thicker the door leaf, the better the sound insulation effect.
4. Choose a common lock security door, that is to say, try not to buy a door with patented lock fittings, because any one can be equipped with parts in the future, and the price is cheaper. If you don't mind changing the security door often, say something else. )
5. Try to choose a metal handle. If the handle material of your favorite style is not good, you can negotiate with the merchant to replace it.
6. Hidden hinge (hinge). D-class doors must have at least four adjustable hidden hinges, which can be fine-tuned when closing, making them more beautiful and safer to hide inside.
7. Choose the combination of doorbell and cat's eye. This kind of accessories can be found everywhere, and it is more convenient to replace them after the shelf life.
8. Stainless steel is inferior. There is a kind of "stainless iron" on the market, which will rust after a long time. It looks dirty and can't be cleaned.
In addition: if only one worker is involved in the installation, you'd better help when screwing the expansion screw. Although it can be installed by one person, the vibration of the drive screw may change the original position of the door. Although it can be adjusted, there is still no firm effect in any place.