Engineering Drawing Problems and Solutions PDF Diploma Mechanical Engineering Drawing Book PDF

What are engineering drawing instruments and uses and lines and types of lines? First, we will see what is engineering drawing. Engineering drawing is a type of technical drawing which is used to clearly define the requirements for engineered items such as views, dimensions, and necessary information. More than drawing pictures, it is also a language, a graphical language that communicates ideas and information from one mind to another. Most important, it communicates all needed information from the engineer who designed the part to the worker who will make it.

Application of engineering drawing is used in ships, manufacturing, the aerodynamics of automobiles, constructions, etc. For let us see different drawing instruments used in engineering drawing. In this we have a drawing board, drawing paper, pins, clips or Adhesive tapes, pencils, T-Square set square scale, drafter, roller, scale protractor, French curves, Compass, and eraser. Hey, it's time to concentrate. Now let us describe each and every instrument. 

The drawing board is rectangular in shape and is made of wood about 25 millimeters thick. It is cleated at the back by two buttons to prevent whopping. The surface of the board should be smooth and it is used to keep the drawing paper. There is a working edge at the side of the drawing board. When selecting a drawing paper, we have to be sure that the size of the paper is smaller than the drawing board.  To hold this drawing paper we use pins or clips or adhesive tapes. Pencils are basically used to draw. The accuracy and appearance of a drawing depend on the quality of the pencils used. The grade of pencils H to H and HB are mostly used. Next is the T-Square.

 It is made of two parts, the stock, and the blade, which is joined together at right angles by means of screws and pins. Square is fitted at the side of the drawing board and it slides along the edge of the board and is used to draw horizontal straight lines. Set square is triangular in shape with one of the angles as the right angle. Two forms of the set Square are generally used, one having angles of 45, 45, and 90 degrees and the other is 30, 60, and 90. Set square is a combination with T-Square is used to draw lines at an angle. A scale is used to draw lines of a specific length. The protractor is flat and semicircular in shape. 

Its circumferential edge is graduated to one-degree divisions and is numbered at every ten-degree interval and is readable from both the ends. The protractor is used to draw or measure angles. The combination of a T-Square, a set square, scales, and a protractor is a drafter.  Its one end is clamped by means of a screw at the edge of the drawing board. The other end is adjustable. It has a scale that is at 90 degrees and also has a protractor that can be rotated at certain angles. This scale can be moved anywhere we want within its limits. Next is a roller scale. It has a roller in it. It is used for drawing vertical lines, horizontal lines, parallel lines, angles, and circles. The next instrument is the French curve. They are made in various shapes one of which is shown here. A French curve is used for drawing curves that cannot be drawn with a Compass.

  It is used to draw curves like Ellipse, parabola, Hyperbola, etc. A Compass is used to draw a circle of a specific radius and an arc at a specific distance. Soft engine rubber is widely used to erase pencil drawings. The eraser should be such that it does not spoil the surface of the paper.  Next, we will see lines and types of lines. Just as in any textbook, we are thought to use the correct words for making correct sentences. Similarly, in engineering drawing, the details of various objects are drawn by different types of lines. Various types of lines are used in engineering drawing.

 Now let us see the different types of lines. First is a continuous thick line. This line is used to display the outline and edges of the main drawing. Next is the continuous thin line. This line is basically used for dimension extension, projection, leaders, hatching, etc. Next is the continuous thin freehand line. This line is used to show short breaks or irregular boundaries. Next is the continuous thin line with zigzags. This line is used to show the long break. Next is the dashed line. This line is used to show the hidden edges of the main object. Next is the chain thin line. Long dash-dotted. This line is used to represent the centerline for circles and arcs. Next is the chain thin line with thick at the end. This line is used to represent the location of a cutting plane.

 First, we have seen that engineering drawing is a type of technical drawing that is used to clearly define the requirements for engineered items such as views, dimensions, and necessary information. It is also called graphical language and helps to communicate. Next, we have seen different drawing instruments used in engineering drawings such as drawing board, drawing paper, pins, clips or adhesive tapes, pencils, T-Square set, square scale, drafter roller, scale protractor, actor, French curves, Compass, and eraser and their uses.