Threaded fasteners or vibration resistant fasteners can be reused and that is the reason they are preferred over permanent fasteners. The reusability of the threaded fasteners is usable in certain conditions. Removing the reusable fasteners is also dangerous. If the fasteners are often removed, they develop the capability of loosening during vibration.
Causes of loosening due to vibration
There are no places where vibrations do not occur. At some places, it is mild while others it is severe. The causes of vibration are many types of movements and sounds. Some examples can be the sound of musical instruments, the shaking of violent machinery, and many others. Mild vibrations cause the loosening of fasteners in a week or more and the period may even be years.
Junker test was invented by German Engineer Gerhard Junker in 1969. The test was developed to check the effect of vibration on nuts and bolts. The engineer developed a machine called Junker, which was used to produce strong vibrations on the bolts. The usage of the machine became very successful so it is still being used in testing the effect of vibrations. The engineer found the result that if axial vibration occurs on the bolts, it causes less damage and the loosening process is very slow. Comparatively, when the fasteners are subjected to direct vibrations, they loosen very easily. The test also helped in checking the fasteners, which are being sold as anti-vibration. He told that these washers are susceptible only for light vibrations, not the heavy ones.
Measures for preventing the loosening of nuts and bolts
Solutions for creating anti-vibration fasteners are being developed continuously. Besides fasteners, many other solutions can act as anti-vibration. These solutions have been discussed here.
There are much thread locking easily available compounds. The thread lockers are available in vibrant colors and can be found in screws that are used in computers, and other electronic devices. It is a misconception that the patches in the screw have the capability of detecting tampering but it is not true. These patches are used to increase the resistance to vibration and friction. Such a compound can be used with any type of fasteners, which are discussed here.
These are the nuts that come with anti-vibration quality. They resist loosening when they face any vibration. Metallic and nylon locking nuts resist vibration effectively. The metal nuts have tight threads providing grip to the screws. Nylon nuts have elastic nylon sleeve, which provides resistance to loosening.
Tri lobular threads
These fasteners have threads in round shape but also have a triangular profile. These threads easily provide resistance to vibration and loosening.
The vibration resistant fasteners or anti-vibration fasteners are used to resist the loosening of the nuts and bolts due to vibration. The Junker test is done to test the vibration resistance and then these are marketed. Many types of fasteners have the property of resisting vibrations and people can buy such screws from the market.