Methods to Keep Bolts from Loosening

We know that loose bolt components may cause very serious consequences, and even threaten people's lives in the production site. If the bolts of a machine in operation are suddenly loosened, it will cause the entire factory to come to a halt. The more serious thing is that it will cause hidden safety hazards for workers and safety accidents, especially it happens in moving airplanes or cars etc. In daily life, safety accidents caused by a small screw can be said to be everywhere. Then how to keep bolts from loosening?

Why the bolt that is tighter will loosen?

When metal bolt part is impacted or collided, why the bolt that is tighter will loosen? Let us take a look at the working principle of the bolt first. It mainly uses the oblique circular rotation and friction of the object to gradually enter the machine parts of the fastening device. And the tightness of metal thread teeth parts between two objects is particularly important. When the bolt is shaken violently for a long time under the frequent vibration, the thread that is tightly engaged will produce tiny gaps or even deformation, and the working state of the machine is mostly time-long and repetitive movement. To a certain extent, it will cause the bolts stamping parts to loosen. In addition to being loosened by severe vibrations, these situations such as embedding, gasket creep and thermal expansion, and strong impacts etc. will also cause the bolts to loosen.

How to keep bolts from loosening?

Since bolts can loosen due to so many reasons, how should we effectively prevent bolts from loosening? Here we introduce several ways for prevention.

1. Add flat washers

It can increase the contact area, reduce the pressure, and prevent bolts stamping components from loosening. However, this method is limited to preventing the relatively weak screws from loosening, and does not have a strong effect to prevent the loosening of the screws due to frequently disassembled and assembled.

2. Self-locking nut

This stamping metal component is self-locking by friction, so the relative rotation of the nut and the bolt can be prevented. So, it has the function of preventing the loosening of screw. But it is a high-end metal stamping part with high cost.

3. Split pin

It is often used to fix the screw stamping parts, but in the process of mechanical movement, the pin may be damaged, and the screw nut is easy to wear, and the thread of ring is broken. So, it is easy to cause the screw and the metal thread part to slip, which will cause the screw anti-loosening performance unstable.

4. Double nut

Usually double nut metal component uses tightening force to make it achieve the anti-loosening effect and increase the weight. But it is limited to relatively weak looseness and cannot have a strong effect for preventing loosening. If it is not used properly, it cannot prevent loosening, and the screw anti-loosening performance is unstable as well. So, the simple way to prevent bolts from loosening is that you inspect regularly.