Bolt connections play an important role in mechanical equipment, but if the bolts become loose, they will cause serious safety hazards or shorten the life of the connection. Therefore, it is very important to take appropriate anti-loosening measures in the design to ensure that the bolts will not loosen in actual use. The following are 8 classic bolt anti-loosening designs.

8 Classic Bolt Anti-Loosening Designs!

When it comes to ensuring the reliability and safety of mechanical connections, choosing the right bolt anti-loosening design is crucial. These designs not only extend the working life of bolted connections but also prevent potential safety hazards. Here, we explore 8 classic methods:

Double nut

Double nut anti-loosening is a common bolt anti-loosening design method. Its principle is to install two opposing nuts on the bolt to generate interactive pressure between them, thus forming friction that prevents the nuts from loosening.

When two opposing nuts are tightened, there is always pressure between them. For any nut to rotate, it needs to overcome the friction between the screw threads. Even if the external load changes, the pressure between the top nuts always exists, so the nuts can be effectively prevented from loosening.

Self-locking nuts

Self-locking nuts are simple in design and easy to use, and are suitable for various scenarios where nuts need to be prevented from loosening. It prevents the nut from loosening by using friction. Usually, embossed teeth are designed on the nut, which is pressed into the preset hole of the sheet metal, so that the diameter of the preset hole is slightly smaller than the diameter of the embossed teeth.

When the self-locking nut is tightened, the embossed teeth will embed into the preset holes, creating friction. This friction can provide enough resistance to prevent the nut from loosening easily. The anti-loosening effect of self-locking nuts mainly depends on friction.

Built-in nylon self-locking nut

This kind of nut has a nylon washer or molded insert embedded inside, using the elasticity and friction of the nylon material to provide an anti-loosening effect. When the nut is tightened, the nylon washer or molded insert will create additional friction to prevent the nut from loosening.

Spring washer

Adding a spring washer between the nut and bolt head can provide additional elastic deformation to keep the tightening force stable and prevent the nut from loosening.

Double layer self-locking washer

Double-layer self-locking washers are a commonly used bolt anti-loosening device. It consists of two circular washers, with the inner and outer washers interlocking with each other via a series of flanges and grooves. The flange of the inner gasket is in close contact with the bolt, providing friction to prevent the bolt from loosening. The groove of the outer gasket matches the flange of the inner gasket, forming a self-locking structure between the two gaskets, further increasing the anti-loosening ability.

Thread locking glue

Thread locking adhesive is an adhesive composed of methacrylate, initiator, accelerator, stabilizer, dye and filler. Thread locking compound can fill thread gaps to form a tight connection and prevent nuts from loosening. It has good high temperature resistance and chemical corrosion resistance.

Slotted nut

Slotted nuts are used with threaded hole bolts and cotter pins to prevent the bolt from rotating relative to the nut. After the nut is tightened, insert the cotter pin into the nut groove and the bolt tail hole, and pull the cotter pin tail apart to prevent the relative rotation of the nut and bolt.

Locking bolt

The locking bolt is designed with a special flange or locking structure in its thread structure, which provides additional tightening force through elastic deformation during tightening to prevent the bolt from loosening.

The above are common bolt anti-loosening design methods. Designers can choose appropriate anti-loosening measures according to actual needs. By adopting these designs, the reliability and working life of bolted connections can be improved, ensuring the safe operation of mechanical equipment.

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