What are the standard sizes of drawing sheets according to I.S.I. and which is suitable for drawing work?

               The standard sizes of sheets according to I.S.I. are;

ISO A Drawing Sizes (mm)

A5   148  X  210

A4   210  X  297

A3   297  X  420

A2   420  X  594

A1   594  X  841

A0   841  X  1189

A2 size is generally used by engineering students as it is very handy and easy for drawing work in class.

ANSI/ASME Drawing Sizes (inches)

A  8.5" X  11"

B  11"  X  17"

C  17"  X  22"

D  22"  X  34"

E  34"  X  44"

Other U.S. Drawing Sizes

D1  24" X  36"

E1  30" X  42"

H    larger still [intracompany standards]

I     larger still [intracompany standards]

J     larger still [intracompany standards]

What is layout of drawing sheet?

          The selection of suitable scale and allotment of proper space for margin, title block, parts list, revision panel, folding marks etc. on the drawing sheet is known as layout of drawing sheet.

Why is the layout of sheet is necessary?

          Layout of the drawing on the drawing sheet is necessary in order to make its reading easy and speedy. The title blocks, parts list etc will provide all the required information.

List out the contents of title block and material list:

The title block should contain at least the following information's.

(i)   Name of the Institution,

(ii)  Name and Roll no. of the Student, 

(iii) Class (with Discipline),

(iv) Scale: (a) full scale (1:1), (b) reduced scale (1: n) &

                 (c) enlarged scale (n: 1) where n=2, 3,4,5…....),

(v)  Drawing Number and Date,

(vi) Symbols denoting the method of projection

       (1st angle or 3rd angle),

(vii) Name of title of drawing.

What is dimensioning?

          The art of writing the various sizes or measurements on the finished drawing of an object is known as dimensioning.

What is the importance of dimensioning?

• Dimensioning expresses all the sizes and other information   necessary to define the object.

•  It must be done with due regard to manufacturing processes and inspection requirements.

• The dimensioning also includes expression of tolerances          necessary for the correct functioning of the part given to be       assembled.

What do you understand by the term notation of dimensioning?

The notation of dimensioning consists of extension lines (a thin continuous line drawn by 2H pencil from the object lines), dimension lines (dimensions are mentioned above the lines which is drawn by the 2H pencil), arrow heads, dimension figures, notes, symbols (Diameter: ø, radius: R, Sphere Diameter: Sø, equilateral triangle: Δ, Square: □) etc.

Composed by:  R.Satheesh, M.E., Asst Prof., email: rsatheeshemail@gmail.com.