Engineering Drawing part -2

CH-1  Drawing instruments and their uses

3-Set -Squares

The set squares are  made of wood, tin and plastic .commonly celluloid or plastic are used  because they retain their shape and accuracy for a longer time.

There are two types of set squares are used 

1-A set square triangular in shape  which have angle 45-90-45 degree  and 250 mm edge length

2- A set square triangular in shape  which have angle 30-90-60 degree and 200 mm edge length














Use of Set Squares


1- Set squares are used for drawing all straight line except the horizontal line because horizontal line draw with T-Squares .

2-vertical lines can be drawn by the help of T-Squares and Set-Squares

3-By using of set squares a circle can be divided in so many parts.

4- It can draw perpendicular lines easily .










4- DRAWING INSTRUMENT BOX

The drawing instrument tools contains so  many tools which are given bellow

1-Large size compass
2-Small bow compass
3-Large size divider
4-Small bow divider
5-Lengthening bar
6-Small bow ink pen
7- Inking pen


1-Large size compass

a- This compass  is used for drawing circles and arc of a circles
b-It consists two legs hinged together at it upper end
c-Pointed needle is fitted  at the lower end of the leg
d-Circle up to 120 mm diameter cam be drawn with the leg of compass

Large size compass

 














2-Small bow compass

a-By the help of small bow compass we draw the small circles and arcs
b-when large number of circles of the same diameter are drawn then we use small bow compass
c-In this compass used H  or HB  pencil to make line or circle in proper darkness.


Small bow compass
























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