 Hello friends, myself S.M. Watt, assistant professor, I am Walsh and instead of Tignol Esolapur. Today I am explaining regarding the sectional view of orthophic projections. That is from three dimensional view we have to draw the three views, front view, top view and side view. But sometimes some added we have to require to clear that object. At that time we have to take a section of this one. So, how to draw the sectional view? Let us go through that. The learning outcome for this process is student will able to draw the orthophic projections of sectional view of simple object. This is the object. So here in the direction of x we have to draw the front view. But that front view is a sectional front view and the sectional line is given is to be here. It is to be from the line a a here and it moves to here and half part you have to cut it. The front portion you have to remove it. So for that purpose first we have to draw the, take the maximum dimensions for that. We have to go for maximum dimensions for that. It is given that from this center line to this center line is 105 plus this radius and plus this radius. 105 plus this radius it is given for this one it is R 20. So 20 plus 105 125 125 plus it is given as 560 means R 30. So 20 plus 105 125 plus 30 155. So make a block of 155. The first one is 20 then 105 plus 30 is the length and the height is given as well. It is given as on the right side that is 60 mm maximum it is 60. So in this block you have to draw all these drawings. Then here in this half part is to be removed here section of this one. So the circular part and the circular part surface we have to see in as it is. So first of all you have to draw the circular part. You draw the clear and in this view this circular part is parallel to you. So that is why you get as a true shape of the circle. So first you have to fix the center line of the circle. It is given as R 20. So from this end you have to travel 20 mm and 20 mm and fix the center line for this one. Okay. So when I have to fix the center line 20 mm for this one and the center one circular hole is there which is parallel to you that diameter is given as 525. So radius is 12.5 mm, 10, 12.5 so draw the center line for this one. Then this rib is there. When you have to cut this portion this incline rib is there and the cylinder is to be seen. That cylinder is to be given as a center line which is R 560 means 30 mm radius is to be there. From this end you have to travel 30 mm and draw the center line 30 this portion is to be 30 mm. And this end that is the rib is to be there 10 mm rib is to be there which is from this end. And when I have to section for that this surface which portion the thickness of the cylinder then the excess cylinder it comes to in front of you. And this rib is to be cut there and this circular portion seen as a hatched one. And for this thickness of this it is given as 540 means you have to travel 20 mm right and left. Hole is 40 mm diameter 10 mm and that is when you have to cut this portion that surface come to you. So it is seen as a regular surface which is parallel to you in front of you. So this surface seen as a one surface is to be there. All this portion this portion this whole surface portion is to be removed only this surface whole surface other right and left surface then incline rib and this portion. But rib is not a part of that object. So leave that rib and it is to be tangents for that where it is it is up to here. So this surface this hatched one is a sectional view. So this hatched portion is a section portion after that. Why this section you have to taken because sometimes some irregular parts are there some hidden surfaces are there. That line will not be shown in the ortho front view top view and side view. So at that time the object is not clear to the observer. So at that time you have to take a section for that to taking the section for that you have to mention the section line where you have to take the cutting plane that cutting plane must be you have to mention it where the section starts and where the section ends one. Here it is shown that it starts here AA and ends up to here and this circular part that surface also you have to see in it this circular part also the section of this one. So this surface is seen as a one surface is to be there. So this is a sectional front view and when I go for a sectional front view this diameters are given as R25, R20. So inner one is to be 525 means 512.5, outer one is R20. The distance between center to center distance is 105. The center line is to be given as 105 and the height is given as 60 mm. Now pause the video think over that why the section of this portion is not shown section this also portion also get cut here this portion also get cut this portion also get cut here why not show the hatched line because you know that this is the supporting rib is there and by our principles by our rules the supporting rib is not a part of that object. So that is why we need to take the section for that that rib the you have not show the hatching line for this rib portion cut portion is to be there references for this one I am taking as a engineering graphics one by a professor M.L. Dabade by Weijan publications thank you.