This document provides an introduction to engineering drawing and the tools used. It discusses the purpose of engineering drawings in conveying shape, size, manufacturing methods and materials. It then lists and describes common drawing instruments like the drawing board, mini-drafter, set squares, protractor, scales, French curves, and templates. Pencils of different grades are used for different line types. Standard drawing sheet sizes from A0 to A4 are defined along with a typical sheet layout including title block and drawing space.

1. B.Tech 1st year (ME)
• Lecture # 01
• Sheet 1- Basic types of Lines

2. Introduction
Engineering drawing
Drawing of an object contains all the necessary information,
required for the construction/fabrication of the object, like
• actual shape,
• accurate sizes,
• manufacturing methods,
• materials to be used etc.
Graphic language: mode of communication through SKETCHES
Drawing: graphical representation of an OBJECT

3. Drawing Instrument
The Instruments and other aids used in draughting work are listed below:
1. Drawing board
2. Mini draughter
3. Instrument box
4. Set squares
5. Protractor
6. Set of scales
7. French curves
8. Drawing sheets
9. Pencils
10. Templates

4. Mini-drafter

5. Mini-draughter consists of an angle formed by two arms with scales
marked and rigidly hinged to each other. It combines the functions of T-
square, set-squares, scales and protractor. It is used for drawing
horizontal, vertical and inclined lines, parallel and perpendicular lines
and for measuring lines and angles.

6. Mini-drafter fixed on a drawing table

7. Set- square
French Curve
Drawing Clips

8. French curves are available in different shapes. First a series of points
are plotted along the desired path and then the most suitable curve is
made along the edge of the curve. A flexible curve consists of a lead
bar inside rubber which bends conveniently to draw a smooth curve
through any set of points.

9. Engineering Drawing Box

10. Scales
Scales are used to make drawing of the objects to proportionate size
desired. These are made of wood, steel or plastic.

11. Pencils
Pencils with leads of different degrees of hardness or grades are available in
the market. The hardness or softness of the lead is indicated by 3H, 2H, H,
HB, B, 2B, 3B, etc. The grade HB denotes medium hardness of lead used for
general purpose. The hardness increases as the value of the numeral before
the letter H increases. The lead becomes softer, as the value of the numeral
before B increases.
Pencils of grades H or 2H may be used for finishing a pencil drawing as these
give a sharp black line. Softer grade pencils are used for sketching work. HB
grade is recommended for lettering and dimensioning.
• HB Soft grade for Border lines, lettering and free sketching
• H Medium grade for Visible outlines, visible edges and boundary lines
• 2H Hard grade for construction lines, Dimension lines, Leader lines,
Extension lines, Centre lines, Hatching lines and Hidden lines.

12. Drawing sheet
Designation Dimension, mm
A0 841 X 1189
A1 594 X 841
A2 420 X 594
A3 297 X 420
A4 210 X 297

13. Drawing sheet Layout
20 mm
10 mm
10 mm
10 mm
170 mm
65 mm TITLE BLOCK
DRAWING SPACE

14. Title Block
10mm
10mm
10 mm
10 mm
10 mm
15 mm
170 mm
85 mm 85 mm
NAME OF STUDENT
UNIVERSITY NAME
CLASS ROLL NO.
TITLE OF SHEET
DATE SCALE
TEACHER SIGN

15. Sheet 1