Engineering Graphics

INDEX Introduction Scales Engineering Curves Orthographic Projection Isometric Projection Projection of Points & Lines Projection of Planes Projection of Solids Section of Solids IN CLASS

Types of Lines Numbering Dimensioning Types of Polygon INTRODUCTION Types of Lines Numbering Dimensioning Types of Polygon

TYPES OF LINES TYPE ILLUSTRATION APPLICATION CONTINUOUS THICK Visible outlines CONTINUOUS THIN Dimension lines, Leader lines, extension lines CONTINUOUS THIN - WAVY Irregular boundary lines SHORT DASHES Hidden outlines & edges LONG CHAIN THIN Center lines, locus lines, pitch circles LONG CHAIN LINE THICK AT ENDS THIN ELSEWHERE Cutting plane lines LONG CHAIN THICK To indicate surface to receive additional treatment RULED LINE & SHORT ZIG-ZAG THIN Long break lines

NUMBERING

STRAIGHT LETTERS & NUMERALS Step-1  First draw two horizontal lines of any length at the distance 10 mm apart from each other. Step-2  Then draw vertical lines between the two horizontal lines at distance 10 mm apart form each other. Step-3  Then write down the Capital Alphabet letters within each box in such a way that each letter of the alphabet should touch the boundary of the respective box only. Like in the same way write down full ABCD…. Step-4  As per the procedure described above write down numerals from 1 to 0 in a new line.

INCLINED LETTERS & NUMERALS Step-1  First draw two horizontal lines of any length at the distance 10 mm apart from each other. Step-2  Then draw vertical lines between the two horizontal lines such that each vertical line should be inclined at an angle of 75° with the horizontal line & each line should be at the distance of 10  mm apart from each other. Step-3  Then write down the Capital Alphabet letters within each box in such a way that each letter of the alphabet should touch the boundary of the respective box only. Like in the same way write down full ABCD…. Step-4  As per the procedure described above write down numerals from 1 to 0 in a new line.

DIMENSIONING There are two types of dimensioning system: Uni-Directional System Aligned System

In Unidirectional Method of  Dimensioning the dimension line should be cut at center and dimensions should be placed in the middle of dimension lines as shown into the figure.

In Aligned Method of Dimensioning the dimension line should be continuous and dimensions should be placed in the middle of dimension lines as shown into the figure

Polygon BASIC DRAWING How to draw a Polygon? TRIANGLE SQUARE PENTAGON HEXAGON SEPTAGON OCTAGON C 6 4 A B 30

TRIANGLE 30 A B C 4 6

SQUARE 30 A B C 4 6 RADIUS O

PENTAGON BISECTOR C 6 5 RADIUS 4 A B 30

HEXAGON 30 A B C 4 6 RADIUS

OCTAGON 30 A B C 4 6 8 RADIUS