 Prof. Prithish Chittay, working in Mechanical Engineering Department in Walchand Institute of Technology, Sallapur. In our third session, we will discuss the different cutting operations which can be performed on lathe machine. These are the learning outcomes. The students will be able to explain different cutting operations that can be performed on the lathe machine. So what we are learning in this session, we will have a quick recap of the second session. What we are learning in the second session after that, we will see the different cutting operations that can be performed on the lathe machine. Now what we have learned in the second session, we have learned the different lathe accessories. You can see the different pictures. Now you can recognize like this is a three jaw check. We have learned a three jaw check and a two jaw check, also a magnetic check, which is a jaw holding device, which is a part of headstock. After that we have learned the face plate. This is a face plate. The face plate can be fixed inside the spindle in the headstock and we can fix the job inside the face plate. The face plate and angle plate can be used combiningly. The wing plate and lathe carriers that can be used combiningly, which is a job holding devices. This is a straight lathe carrier and this is a bent lathe carrier. After that we have learned the lathe centers. There are the different types of lathe centers like a standard center, half center or the revolving center, which is a part of a centers, which will be supporting part for the to hold the job. There are the main two types of centers like the live center and the dead center. As we have discussed in the last session that the live center is present at the headstock part and the dead center is present at the tailstock part, mandrels. So these are the some of the types of the mandrels. So for example, plain mandrel or the color mandrel or the step mandrel. The function of mandrel is that whenever we want to hold a very lengthy job, which is having very high length and that can't be supported by a maybe a chuck or maybe the face plate or maybe the centers. But we can use the mandrels. Also suppose you are having the boring part. Suppose you are having the boring part, so that can be used in the mandrels. Steady rest and follow rest, this is the steady rest and follow rest. So this is also used to hold the lengthy work pieces. Now very simple question, for holding lengthy work pieces, which length accessories can be used? Just think about this question and just please have the answer for with you. Now in this session, mainly our objective is to learn the different lathe operations. You can see the list of the lathe operations, like the turning operation, facing operation. These are the very basic operations, taper turning operations, threading operation, drilling and boring, grooving, knurling and parting off. Parting off is the last operation. Now we will see in detail turning operation. Turning and facing are the basic operations. Lathe operations means to remove the metal during the actual cutting operation. For example, in the turning operation having the turning between the centers, so this is a live center and this is a dead center and we are having a driving plate here means the job is supported with the help of the live center and the driving plate and the end of the driving plate is attached to the tail of this lathe carrier or the lathe top. So this is the left end of the work piece. So work piece will be supported with the help of three job holding devices like the lathe carrier, the live center and the driving plate as per the requirement and to the right side you can see there is a dead center which is a part of tail stock. So the right side of the work piece will be supported with the help of dead center that is tail stock. Now how the turning operation will be carrying out? Now you can see the tool is having the movement in the linear direction to the left hand side or maybe the right hand side. So suppose the tool is moving towards the axis but your tool is moving parallel to the axis of rotation of the work piece. Always remember in the turning operation the tool is moving parallel to the axis of rotation while the your work piece or the job or the component or the product is rotating. So the tool is moving in the parallel to the axis of rotation. So here whenever you want the metal cutting operation there should be the relative motion between the tool and the work piece. After that only there will be the cutting operation. So here so which parameter there will be the changing? It may be a length or it may be a diameter there are the two chances. So here you can see the tool is moving parallel to the axis of rotation means the diameter is changing here. There will be the decrement in the diameter during the turning operation. So now there are the two operations first will be the rough cutting operation or the rough turning operation. So this is the rough turning operation and this will be the finish turning operation. In the rough turning operation the depth of cut and the feed will be heavy because we have to remove heavy stock of material in the rough turning operation first of all. Due to the heavy stock of material the surface will be rough 0.7 mm to 7 mm we can take the depth of cut also the feed will be higher. The chip will be also a large you can see the chip thickness will be a very large as compared to the finish turning operation. Now here very small material will be remained during the finish turning operation. So in the finish turning operation you can see the chip is very less here and the depth of cut will be also very less and the feed also very less the work piece is rotating and the tool is having the motion parallel to the axis of rotation of the job. So very less material will be removed during the finish turning operation. Now the next will be the facing operation the half center use that is the type of the center now you can see here the tool is moving perpendicular to the axis of rotation. This is your axis of rotation and the tool is moving perpendicular to the axis of rotation in the facing. Now suppose there is a metal removal process there. So we are having the length reduced during the facing operation always remember in the facing there will be the reduction in the length and in the turning there will be the reduction in the diameter. You can see the tool is moving perpendicular to the axis of rotation. This is the work piece which is rotating and the work piece is hold between the chuck. This is the part of the headstock and there are the two ways we can hold the tool. Now the tool may be having the 90 degree or you can place the tool just parallel to the axis of rotation and the tip of the tool will be touching to the your work piece just like this and the half center is used during the facing operation. So here also we can perform the rough facing operation and the finished facing operation just like the turning operation. Now we will move to the next operation that is the drilling operation. You can see in the diagram the work piece that is the cylindrical work piece and which is fixed in the maybe a 3 jaw chuck or maybe the 4 jaw chuck in the headstock. This is a tailstock and this is a barrel and the sleeve where your tip of the drill will be fixed or the drill tool will be fixed inside this and the tip of the drill will be touched to the work piece for the concentric or the center after that only the drilling operation will be done. And suppose you want to take the drill inside the work piece we are using the hand wheel manually to take the drill inside the work piece. Now how much depth of cut we want? We are marking the particular maybe a 3 mm or maybe the 4 mm we want the depth of cut we are marking on the drill tool. The next one will be the boring tool. You can see the type of the boring tool. This is the rough boring tool and this is the finished boring tool that can be used for the rough boring operation. The heavy stock of material that can be removed and the finished boring operation where very less material that can be removed but the surface finish will be higher in the finished boring operation. This is a cylindrical boring bar where we can use it in the boring operation. There are the two types boring a blind hole and the boring a throughout hole. Boring operation is a next part of drilling. Suppose you are having the hole that is already done maybe the casting or maybe the forging and suppose you want to just enlarge the hole yes we can use it as a boring operation. These are the references thank you.