Introduction to Engineering Drawing

What is Engineering Drawing ?

It is a language for transferring the details of an object to the labor who works in the manufacturing field.

When a multi-storied building is constructed, the primary need of the labors is Engineering Drawing. All details like dimensions, door-window details, floor-roof details, false-ceiling details if any and staircase dimensions, etc, are reflected in the Engineering Drawing. The labors may not know the reason behind the design parameters of the staircase, but they surely know how to read the Engineering Drawing and how to start erection works accordingly.

Therefore, It is a language by which engineers and labor communicate with each other for construction works.


The following instruments are used to prepare drawings easily and accurately:

  1. Drawing Board
  2. T-square
  3. Set Squares-45 degree and 30 degree -60 degree
  4. Compass
  5. Divider
  6. Scales
  7. Protector
  8. French Curves or flexible curves
  9. Drawing Sheets
  10. Pencils
  11. Eraser
  12. Drawing board clips
  13. Duster made of cotton
  14. Drafting machine

Size of Drawing Sheets:(mmxmm) 

  • A0: 841 X 1189
  • A1: 594 X 841
  • A2: 420 X 594
  • A3: 297 X 420
  • A4: 210 X 297
  • A5: 148 X 210

Purpose of some new instruments:

T-square: used for drawing the horizontal lines, vertical lines.

Set-square: In combination with T-square, set squares are used to draw the lines at 30 deg or 60 deg angle and 45 deg angle with vertical or horizontal lines. Also used for drawing perpendicular lines and parallel lines.

Drafting Machine: the tasks performed by T-square and Set Square, all these tasks can be performed by only using drafter. 

French Curves or flexible curves: These are used for joining the points on the curves while creating the geometrical curves.

Basic things you should know:

1. Dimension Systems:

Under this section, you will come to know how to put dimensions in an Engineering Drawing.

2. Scales:

you will learn how to scale the object for accommodating the object in the drawing sheet.

3. Construction of Geometrical Curves:

In this section, how to draw the basic geometrical shapes e.g polygon, parabola, ellipse, etc will be taught to you.

4. Projection of Points and Lines:

Here, you will learn about the different types of projection- first angle projection, second angle projection, third angle projection, fourth angle projection. If a point or a line is situated in the first quadrant, how to draw the projections of those points in a drawing sheet has been explained under this section.

5. Projection of Solids:

Here how to draw the different views of a 3-d solid object has been discussed.

6. Projection of Sections of Solids:

If the object is cut at a particular height and a particular angle, the different views of the cut object has been explained here.

7. Isometric Projection:

Differences between the orthographic projection and isometric projection have been discussed here. You will learn how to draw the isometric projection of an object.

8. Development of Surfaces:

If all the surfaces of an object are developed or opened, how will it look has been taught here.

Thank you for reading. Let us make a beautiful world together. God bless.