The screw of aluminum profile frame is always loose, that is, the screw connected between aluminum profile and aluminum profile will be loose during transportation. What should I do? What should I do?

This method is also a non-detachable locking method for screws and nuts. After the fasteners are installed, the screws and nuts are directly welded on the screw holes by electric welding and other methods. 1. Install the loosening washer. 2. Change ordinary bolts into locking bolts. 3. Install the thread sheath in the screw hole.