Hexagon Socket Head Bolt is a common Hexagon Socket Head Bolt connection part in our lives, ranging from small screws on watches to large mechanical parts or aircraft bolt and nut connections. The use range of Hexagon Socket Head Bolt is very extensive, but in the process of using it, will you encounter some misunderstandings, for example, if we don't have fine-tooth bolts, can we replace coarse-tooth bolts? When using Hexagon Socket Head Bolt, the common misunderstandings are mainly the following, I hope to help everyone.
What are the misunderstandings when using Hexagon Socket Head Bolt, how much do you know?

1. Use coarse teeth instead of fine teeth

There are many important connectors on the machine, such as the drive shaft, etc. Most of the bolts are fine-threaded. If parts are missing during maintenance, some maintenance personnel will use coarse-tooth bolts instead, which should be avoided.

Because the fine-diameter bolt has a large inner diameter, a small pitch and an external angle, high strength, good self-locking performance, and strong ability to withstand shock, vibration and exchange loads. Once replaced with coarse-tooth bolts, it is easy to loosen or disengage, disassemble, and even cause mechanical accidents.

2. Poor pores

The bolts on the machine that are subjected to lateral loads and shear forces, such as drive shaft bolts and flywheel bolts, have a transitional fit with the bolt holes. The assembly should be strong and reliable, and can withstand lateral forces. Someone did not pay attention to the inspection during the assembly process, and continued to install when there was a large gap between the bolt and the bolt hole, which was easy to loosen or cut off the bolt.

3. Thick nuts increase connection reliability

Some people mistakenly believe that thickening the nut can increase the number of working cycles of the thread and improve the reliability of the coupling. But in fact, the thicker the nut, the more uneven the load distribution among the threads of the circle, the easier the coupling is to loosen.

4. One mother and more pads

After the installation is completed, sometimes the bolts are too long, so some people will install additional spring washers on the bolts.In this case, the spring washers will be unevenly broken during the process of solidification, which will cause the bolts to be pre-prepared. Decreased tightening force may also produce eccentric loads, reducing the reliability of bolted connections.

5. The tighter the better, the better

Many staff members have the misunderstanding that they think that the bolts should be “tightened rather than loosened”, so they deliberately increased the tightening torque, which resulted in the bolt slipping. In addition, there are some important bolts that need to be tightened with torque, but some people use an adjustable wrench to save the trouble. As a result, the torque is insufficient, resulting in loose bolts and even causing mechanical failure.

6. The washer is too large

Sometimes a properly sized washer is missing, and some workers will replace it with a larger inner diameter washer.In this case, the contact area between the bolt head and the washer is small, which will reduce the bearing pressure or locking force of the washer. There is vibration and shock in it, and the bolt is easy to loosen.

7. Improper locking

Important bolts should be locked with anti-loosening devices after assembly. There are four cases to illustrate here. If cotter pins are used for locking, do not use too thin cotter locks or half-piece cotter locks for locks; if spring washers are used for locks, the gap of the gasket openings must not be too small; if lock plates are used for locks, the lock plates must not be locked at The corners of the nuts; if double nuts are used for locking, the thinner nuts must not be installed outside.

8. False and strong

If the bolts, nuts or threads of China Fasteners Suppliers are rusted, or impurities such as scale, iron filings, etc., they must be cleaned before assembly; the joint surface of the coupling parts have burrs, sediment and other impurities should also be removed. Otherwise, when tightening the bolts, the surface seems to be tightened, but in fact the coupling is not really compressed. Under such false solidity, if the vibration, load shock and temperature change occur, the bolt will quickly loosen.