 This is Shila Ratna Bansori from Walshan Institute of Technology, Solapur. As a part of machine-train curriculum, we are going to see the BIS conventions, that is, the conventions specified by Bureau of Indian Standards. And in that, specifically, we will be seeing the conventions for sections and certain engineering materials, moving further. At the end of this session, the students will be able to apply the BIS conventions for section and engineering materials. Now, I suggest you to pause the video at this moment and recall what is BIS and what work does it do? Moving further. Now, as we have seen in the previous videos, that BIS stands for Bureau of Indian Standards. This body defines the standards that are being used in engineering applications. Now, these standards are derived from the international standards. And by making certain changes and making it compatible to be used in the nation, certain changes and re-framed conventions are being provided. So, any engineering drawing contains the conventions that are being preferred, that are being suggested by the Bureau of Indian Standards, that is, BIS. Conventions helps us to make the drawing easy to understand. It does not make it confusing. The ideas are cleared or the message is converted in a short form, in a short small diagram without having a lengthy note on it. Let us move further. Now, in this video, we are going to see about sections first and then about materials. Now, as we all know, sections are taken or section view is considered to see the inner detail of a machine component. The inner detail of any machine component can be highlighted in the drawing by taking a proper sectional view. In this, we imagine that the object is cut by a cutting plane. And by removing the cut portion, we draw the object in a particular view with the hidden details and section lines. Now, the cutting plane that is used to indicate the cutting direction is represented by two capital letters at the end each. And also, the direction of observation, direction of view week is shown by the help of arrow. And in the direction of the arrow, we have drawn the sectional view. Moving further, now to show section views, we require hatching. As we all know, when you take a section, we have seen in engineering graphics that whenever we take a section, we show hatching lines or section lines. Now, these are used to show where a section has been taken, where have you taken a section. These are continuous lines. These are continuous lines and at an convenient angle. They are not exactly vertical, not exactly horizontal. A certain convenient angle is preferred. That is 45 degrees mostly. So, 45 degree is the angle that is mostly used to show section lines. Plus, the distance between two lines is constant. So, the lines are equally spaced, the distance here is same, the lines are equally spaced. So, equi spaced and inclined at 45 degrees is the standard or is the rule that we follow to give the sectional view or to draw hatching lines. Now, moving further, introduction to hatching. Same here, when you have two different sections of a same component, two different sections, two different parts of a same component, you show it by the same hatching. That is, if you are using hatching lines inclined at 45 degrees towards the right. So, for two sections of the same component, use the same lines that is inclined at right side at an angle of 45 degrees. But when you have two adjacent components and you want to show hatching into that, you show two different types of hatching. In one component, you can show inclined at 45 degrees towards the right and in another component, you can show inclined at 45 degrees towards the left. So, the differentiation of the two different components can be made by same pattern of hatching lines inclined towards at different directions, one towards the right and one towards the left. But same section of two sections of the same components, same hatching line inclined towards the same direction. Adjacent components, yes, two different directions inclined at same angle, 45 degrees, one towards the right and one towards the left. Then, when you have a large area, when you have a large area and you want to show hatching into it, the basic aim of the conventions is to reduce the time required to complete the drawing. If you want to hatch a large area, no doubt it gets into time consuming. So, conventionally, we hatch only a limited zone of that large area that needs to be hatched. A small portion of that area can be hatched to show that it is a sectional view. This is only for large areas, very big drawings. And as far as possible, hatching should not be interrupted. Hatching should not be interrupted. No overwriting over the hatching, no breaking of the hatching lines or section lines. And if you cannot avoid it, a slight breakage of the hatching lines is permitted but to add the extreme conditions. They have to be continuous and thin, equally spaced at an angle of 45 degrees. Moving further, coming to cutting planes. To show section views or a sectional view, we use cutting plane in one view and the section is shown in another view. This, the line that is used to show cutting plane is called as H type of line. H type of line is you have a bigger dash followed by two small dash, then a bigger dash followed by two small dash. This is the pattern of H type of line called as section lines. The ends of the section line are made dark, the ends of the section line or section plane or cutting plane are made dark, the arrows are shown at this point, the arrows are shown at this points. The ends of the line is represented by two capital letters represented by two capital letters, same letters. So this is the cutting plane XX, cutting plane XX. And this is the sectional view in XX direction. this is the sectional view in xx direction these arrows pointing towards the upward shows that in this view you have to draw in this direction you have to draw the sectional view now when you have ribs fasteners or shafts or spokes of wheels in these parts you do not show sections or these parts are not cut in longitudinal directions no longitudinal section is being taken place as we all know sections are used to show inner hidden details and if you cut these components in longitudinal direction no details can be seen no details can be seen so to avoid this to avoid time consumption we do not hatch these standard parts let us see how they are seen here these are the two plates that are being joined with the help of this nut and bolt arrangement so in this bolt there is no hatching in this nut there is no hatching these are two different components adjacent components hatching in different way one towards the right and one towards the left here also a shaft and a pin or a cotter is used so no convention into this here two plates are joined together with the help of rivet in rivet no hatching no hatching in rivet then here is some mounting over the shaft here no sections in the shaft and no sections into this rib and it is cut in longitudinal direction so no hidden details over here no hidden details over here and here full section no sections in this holes moving further types of sections one is revolved section and other is removed section in revolved section the cross sectional is revolved to show the cross section and hatching is done into it in removed section you take the section and only the cross section is drawn separately with hatching then we have half section where the half view is in sectional view then we have local section where you want to show specifically at certain point the hidden details you go for local section no need to entirely section the body only the specified portion can be sectioned specified portion can be sectioned then conventional representation of certain materials for metals we go for these conventions like steel cast iron we go for this convention it is a pattern of hatching lines we consider most of the components made up of steel or cast iron then for lead zinc and tin we go for this convention for glass we have this convention so if you want to represent glass metals you can go for these conventions further for packaging and insulating materials that to porcelain other things this convention is used asbestos and other fiber this convention is used for liquids that is water oil or kerosene petroleum you go for this convention for wood you go for these conventions and concrete is shown by this convention concrete that is a mixture of cement sand and grivel so these are certain engineering materials popularly used engineering materials and their conventions these are the references thank you