 Hello everyone, this is Shila Ratna Bansode from Walshan Institute of Technology, Solapur. Today we are going to see the topic freehand sketch part 4 and in that we will be particularly looking into lock nuts. Moving further, the learning outcomes, students will be able to describe different types of lock nuts. Now at this moment of the video, I suggest you to pause the video and recollect the different types of nut and bolt arrangements that you have seen in the previous videos. Moving further, lock arrangement for nuts. The nut and bolt arrangement needs to stay firm in the application. They should not get loose so that the intended function of the component or the part of the machine is run, is done smoothly. The loosening of the nut and bolt arrangement should not happen. The joints may be subjected to vibrations. The nut and bolt joints may be subjected to vibrations if they are on the machines or some automobiles. Due to vibrations, the joints may get loosened in due course of time. And this may result into slacking joints as discussed and may also cause breakdown. To avoid slackening, different arrangements are used. To avoid accidents due to loosening of the nut and bolt due to vibrations or due to some other reasons, we have certain lock arrangements, certain precaution measures that are being used so that the loosening of the nut is avoided. Moving further, the very first type of locking method is with the help of lock nut. So here you can see two nuts. The smaller one is called as lock nut and this is your regular nut. So in the bolt, first the lock nut is inserted and tightened and then your regular nut is inserted. On tightening of the regular nut, this lock nut is rotated in loosening fashion. This nut is slightly made loose so that the threads of this lock nut apply pressure on the threads of the bolt. Similarly, this is made totally tight, the regular nut is totally made tight and this also applies pressure on the threads of the bolt. Because of the pressure of the lock nut and the regular nut, there is a wedge action being created and loosening of the bolt and nut arrangement is avoided. This is a common method of locking the nut or reducing the slackening effect. Then we have locking by split pin. This is also a common method that is being used. In this, there is a hole drill into the bolt or the shank part of the bolt, length of the bolt. Here you first tighten the nut and then you insert a split pin through this hole as you can see in this view. So you insert a split pin. When the pin is inserted, you open the ends of the pin. This also avoids the loosening of the nut as this pin prevents the upward movement of the nut. This type of arrangement is also seen in automobiles or in ceiling fans. Then we have castle nut. In castle nut, the nut has some slots formed into it. So this is your nut and this is the upper part where some slots are cut in U fashion. And there is also a hole drilled into the bolt. Here similar to the previous one, split type of nut. Here also there is a hole drilled into the bolt. Now this hole of the bolt and this slot of the nut are matched together or are bought in line together and then a split pin is inserted. As you can see on screen. So here you can see these are the slots being cut on the nut. So this, this, this and these are the slots being cut on the nut and pin is inserted. Now here you can see the pin is shown in dotted form. This shows that the pin is moving through or has been inserted through the bolt or the hole drilled into the bolt. And then the ends of the pin are opened. This type of locking you can see in bicycle wheels or two wheeler wheels, motorcycle wheels. This is a type of hexagonal nut but that extra part is being added over here which is in the form of used slots which looks like a castle. So called as castle nut. Then we have wiles nut. In wiles nut you can see a slot is being cut in horizontal fashion in this way. This is the hexagonal regular nut and a slot is being cut into this. And then a screw is inserted into this nut in this way. A screw way is formed and screw is inserted. As you type the screw there is the two parts. This is the lower part and this is the top part. Come in contact with or have a tight effect because of which wedge action is being formed on the threads of the bolt and threads of the nut. Due to this the loosening of this nut is avoided. So this is with the help of wiles nut. You can see in top view this is your regular hexagonal nut and this is the screw that is being inserted into the slot. Then we have locking by set screw. This is your regular hexagonal nut. Here you can see clearly and then a hole is drilled in the part. The part which is joined together with the help of nut end bolt and this is created in such a way that the screw inserted into the hole touches one of the flat face of the hexagonal nut. So this avoids the rotation of this hexagonal nut and prevents the slacking. Then we have groove nut. Now this is your regular hexagonal nut and to this regular hexagonal nut a collar is formed. So this collar is an integral part of this nut which gets inserted into the component to be joined with the help of this nut end bolt arrangement. So this is the collar and in the collar there is a groove formed. So this is the groove formed in the collar. And this collar is inserted into the hole of the component that is being joined as you can see on the screen and this is your regular hexagonal nut that is seen above the component. Now horizontal hole is also being drilled over here as you can see on the screen this way. In this a screw is inserted which gets inserted into this groove also. As this screw gets inserted into this screw the loosening effect there is a force being created which does not allow the nut to get loose. So this is the locking of the nut with the help of groove nut. So this is the groove nut which is get inserted into the groove formed in the collar of the hexagonal nut. Then we have locking by screw. As you can see this is an hexagonal cap nut and in the cap we have a hole drilled through and similar hole is also drilled on the bolt. When you tight this cap nut on the bolt a screw is being inserted from the top which also gets inserted into the bolt. This prevents the loosening of this cap nut from the bolt. Then we have locking by plate. So this is a plate that is being used which has a shape that can accommodate the hexagonal shape of the nut. This plate is fixed to the component that is being joined together with the help of this nut and bolt. It is screwed to that component as you can see on the screen. This is the screw that is used to keep the plate in fixed position. And this plate prevents the loosening of this nut because of this zigzag fashion. Now to remove this you first need to remove this plate by removing this screw. Then you remove the plate and then you can lose this nut. So mostly this is used where the nut and bolt is exposed to vibrations. Then we have locking by spring washer. Locking by spring washer you can see it in automobiles. Locking by spring washer here you can see this is the bolt. Then this is your regular hexagonal nut and this is a spring washer. This will be single or double depending upon the application or the vibrations or the forces that you need to apply so that the tightening of this nut is in place. So first in the bolt you insert the spring as you can see over here and then the nut is tight. The nut is made tight. Then you rotate this nut to form a tight joint. As you apply pressure on this nut to form a tight joint the spring is being compressed. But due to the retracting force of the spring there is an upward force being created on the nut and the component due to which there is a wedge action or friction or stopping action by the threads of the bolt and the nut which prevents the locking of this nut and slacking of this nut is reduced or stopped or the loosening effect of this nut is reduced. So this is the spring washer depending upon the application this can be single or double mostly it is seen in automobiles. So this was locking of the nuts in different applications by different methods. References. Thank you.