Vibration is the enemy of the living and running machine.
Oftenly it loosens the fastners connected with the machine to clamp the parts together and thus the machine breakdown.
How do these fastners get loosened up?
Some tolerance is provided between male and female part of the fastners so that it fits in and then gets tighted up.
But after tightening the bolt there is some clearance left out.
And when the machine starts running vibration is produced and the bolt gets loosened up.
In order to avoid this problem loctite is one of the solution. It is a paste when applied to the thread of the screws it sets between the gaps and cease the clearance.
Basically this loctite gel increases the required torque to be applied to open up the fastners.
Different types of solutions are available for different types of materials. The selection of the paste is based on the type of material and the amount of torque required to open up the fastner.
Nylock nut could be replaced with hex nut. When applying this paste.