What are the anti-loosening methods for fasteners?

Use mechanical fasteners to fix and pin the screw and the connected piece or between the screw and the screw to prevent loosening.

1. Non-removable anti-loosening

Use mechanical fasteners to fix and pin the screw and the connected piece or between the screw and the screw to prevent loosening. The advantage of this method is reliable anti-loosening, and its anti-loosening reliability generally depends on the static strength or fatigue strength of the mechanical fastener (or the fastener itself, such as a slotted nut). The disadvantage is that the weight of the fastened connection is increased, the manufacturing and installation are troublesome, and the mobile installation cannot be performed, so the cost is relatively high. Due to its high anti-loosening reliability, it is still widely used in some important parts of mechanical products and aerospace products. -Glued screws

Bolt (or screw) head and nut end face punch point riveting: After tightening, use punch point riveting to locally deform the bolt (or screw) nut to prevent them from loosening each other.

Bonding of locking adhesive: Apply epoxy resin or anaerobic adhesive on the surface of the matching thread. After the adhesive is cured, the matching thread can be firmly bonded to achieve the purpose of locking and preventing loosening. Different adhesives tend to have different locking capabilities. Fasteners coated with epoxy resin have high bond strength and are not removable. Although the fasteners coated with anaerobic adhesive can be disassembled, the adhesive remaining on the thread surface after disassembly is difficult to clean, and the threads may be damaged, so the fasteners should not be reused.

Adhesives can also be used as thread sealants, but they cannot withstand high temperatures. The best adhesive can work at a temperature of 230°C; the worst adhesive, its working temperature is only 94°C.

2. Anti-loosening to increase friction

The purpose of preventing loosening is achieved by increasing the friction between the threads or the head of the bolt (screw) and the end face of the nut, or by increasing the friction of both at the same time. Its biggest advantage is that it is not limited by the space used, it can be repeatedly assembled and disassembled, and it can be assembled by motor. This anti-loosening method is the most widely used in the machinery manufacturing sector and aerospace field. -Lock screws