 Hello everyone, this is Shila Ratna Banshwade from Walchand Institute of Technology, Solapur. Today we are going to see the topic freehand sketches part 5 and in that particularly we will be dealing with rivets and riveted joints. Learning outcomes for this session, students will be able to describe different types of rivets and riveted joints. Now at this moment I suggest you to pause the video and recall the structures or the components which you have seen are formed with the help of rivets. Now moving further, riveted joints or rivets are a round rod of circular cross section. Rivets are used for forming permanent fastenings or permanent joints. They are made up of mild steel, wrought iron, copper and aluminum alloys. The common method of producing rigid and permanent joint is riveting. With the help of this you can form joining of sheets to form boilers, storage tanks and most commonly you must have seen the riveted joints in bus bodies. Also the riveted joints are used in structural work like bridges and roof trusses. On the screen you can see the image of a rivet where this part the lower part is called as head which will be seen once the riveting has been completed and this part is called as shank. So you can say that rivet can be divided into two parts one is head and the other one is shank. So this was general with rivets. Now moving further we have riveted heads. Just now in the previous slide we have seen the head and based on the shape of this head we have different types of rivets. The first one is snap head. It's in a circular fashion. Then we have high button head. Then we have pan head which is slightly flat at the top. Then we have cone head which is the frustrum of cone you can see. Then we have round top countersunk head over here. This head is in the form of countersunk so this is called as round top countersunk head. Then we have countersunk head flat this where here it was in round fashion whereas here it is in flat both below the head top surface it is in countersunk fashion here also it is in countersunk fashion. Then we have flat head it is totally flat at the top surface and it is above the component to be riveted. The head is above the component to be riveted whereas in this type the head gets submerged in the component or gets inserted totally into the component. Then we have truss head which is slightly in parabolic shape over here. So these are the different types of rivet heads or different types of rivets classified on the basis of structure or shape of the head which are used depending upon the application. Depending upon the application we go for these types of heads. As far as this countersunk rivet is concerned where you do not want the rivet to be protruded or do not want the rivet to come out of the riveted surface we go for this. And others depending upon different applications we go for these types of riveted heads. Now moving further with riveted joints the first one is single riveted lab joint. As far as lab joint is concerned one plate is placed over the other one sheet metal is placed over the other as you can see on the screen. So this is called as lab one is placed over the other and then the rivet has been inserted and then pressure has been applied. Now riveting is done with the help of manual hammering or with the help of pressurized tool. Depending upon the application the reliability that you want we select either manual hammering or pressurized riveting of the rivets. Now here you can see in single riveted as it can be seen single riveted the rivets are in single line. Lab joint because the two plates are one above the other. Now next double riveted chain lab joint. Lab joint one over the other the plates are placed one over the other. This is the front view and this is the top view of the two plates. In the previous one there was only one line of rivets only single line of rivets. Now in the next case we have two rivets placed side by side. The two rivets are placed side by side. This is called as pitch of the rivet. The center two center line distance between two center lines passing through the rivets the first center line and the second center line and this is called as the pitch. Now here you can see the two rivets are placed side by side and in a line. So this was double riveted because two riveted lines are there. Chain because one after the other and lab joint the plates are placed one above the other. Next we have double riveted zigzag lab joint. Double riveted because we have two lines of the rivets then zigzag because one rivet is placed in between the other two in front of it opposite to it but in between of these two rivets and lab joints because one plate is placed over the other. This is the section view the cutting plane passes through here it cuts this rivet so this rivet is clearly seen whereas the rivets in this area are not cut by the section plane so it is shown in dotted lines. So this was with double riveted two lines zigzag the pattern is zigzag and lab joint because the two plates are placed one above the other. Then we have single riveted single strap butt joint. Now these are the two plates this is the first plate and this is the second plate which are to be joined with the help of additional plate called as strap. So this is the additional plate that is used to join these two plates. The bottom two plates are joined with the help of this by riveting. So single riveted single riveted single strap single strap because only one cover plate is present and butt joint because the plates or the parts which are to be joined are placed face to face. Here this is the first plate this is the second plate which are to be riveted are placed face to face in front of each other so called as butt joint. Single riveted because single rivet passes through single plate. So this is the single plate and single riveted line. This is the second plate and through it passes through the single riveted line. So single riveted single strap butt joint. Then we have single riveted double strap butt joint. Single riveted this is the first plate this is the second plate and in that only one line of rivet passes one line of rivet passes one line of rivet passes. Double strap because we have two plates two cover plates the first cover plate and the second cover plate. So double strap and butt joint because the two plates which are to be joined together are placed face to face next to each other. So in between we have these two plates in butt fashion and two cover plates so double strap. Single riveted one line double strap two cover plates and butt joint because the two plates are placed in front of each other. Then we have double riveted double strap chain butt joint double riveted this is the first plate to be joined this is the second plate to be joined. We have two cover plates and through each plate to be joined there are two lines of rivets two lines of rivets. So double riveted double strap chain butt joint. Then we have double riveted double strap zigzag butt joint. Double riveted two riveted line passes through a single plate double strap because two cover plates are present and zigzag because the rivets are arranged in zigzag fashion for each plate to be riveted. So this was with the rivet these are the references thank you.