STANDARDIZATION OF DRAWING PAPER

Standardization Of Drawing Paper

Engineering designs should be drawn using standard drawing sheets. The correct shape and size of the thing can be seen by knowing not only the many sorts of lines utilized, but also the measurements, notes, scale, and so on. The drawings must be made in accordance with specific standard methods in order to offer accurate information about the drawings to all parties involved. Engineering drawings are created on standard-sized drawing sheets. The use of standard size sheets saves paper and makes drawing storage more convenient.

Sheet Size

The basic principles involved in arriving at the sizes of drawing sheets are:

where X and Y are the sheet's sides X = 841 mm and Y = 1189 mm for a reference size A0 (Table 1 prefered sheet size) with a surface area of 1 m². The subsequent format sizes are obtained by half the length or doubling the breadth, with the areas in the ratio 1:2. (Fig.  below).

The original drawing should be done on the smallest sheet possible to allow for the required clarity and resolution. Table 1 shows the preferred drawing sheet sizes according to ISO-A series (First option). Special enlarged sizes (Second option) are utilized when longer sheets are required (Table 2). These dimensions are obtained by extending the ISO-A series' shorter sides to lengths that are multiples of the chosen basic format's shorter sides.

Tabel 1 Preferred Drawing Sheet Sizes (First Choice) ISO-A Series

Tabel 2 Special Elongated Sizes (Second Choice)

Tittle Block

The location of the title block, which contains the drawing's identification, should be at the bottom right hand corner of the drawing space. Both horizontally and vertically oriented papers must adhere to this rule.

In general, the viewing direction of the title block should match that of the drawing. The title block can be up to 170 mm in length. Figure below depicts a typical title block, which includes the following details:

• Title of the drawing
• Sheet number
• Scale
• Symbol, denoting the method of projection
• Name of the firm
• Initials of staff drawn, checked and approved

Border and Frame

All sheet sizes should have borders encompassed by the margins of the trimmed sheet and the frame, restricting the drawing space. For the sizes A0 and A1, a minimum width of 20 mm is advised, and for the sizes A2, A3, and A4, a minimum width of 10 mm is recommended. On the far left edge of the title block, a file margin for perforations may be included..

Centring Marks

Four centring marks may be supplied to help position the drawing when it is reproduced or microfilmed. To indicate the orientation of the drawing sheet on the drawing board, two orientation markers may be given.

Mertric Reference Graduation

On all design sheets intended to be microfilmed, a figure-less metric reference graduation with a minimum length of 100 mm and divided into 10 intervals is recommended. With a minimum width of 5 mm, the metric reference graduation can be placed symmetrically around a centring mark at the frame at the border.

Grid Reference System (Zoning)

For all sizes, a grid reference system is advised to make it easier to locate details, additions, adjustments, and other changes on the drawing. The number of divisions should be divisible by two and selected in proportion to the drawing's complexity. The length of any side of the grid should not be less than 25 mm and not more than 75 mm, according to the guidelines. Capital letters along one edge and numerals along the other edge should be used to refer to the grid rectangles. Starting from the sheet corner opposite the title block, the numbering direction can be repeated on the opposite sides.

Trimming Marks

Trimming marks can be placed in the sheet's borders at the four corners to make trimming easier. These marks can be two short strokes at each corner or right angled isosceles triangles.