A drawing is a graphical representation of an object, or part of it, and is the result of creative thought by an engineer or technician. When one person sketches a rough map in giving direction to another, this is graphic communication. Graphic communication involves using visual materials to relate ideas. Drawings, photographs, slides, transparencies, and sketches are all forms of graphic communication. Any medium that uses a graphic image to aid in conveying a message, instructions, or an idea is involved in graphic communication.

The economical success of any country is mainly depended on its industrial development. Due to the globalization any industry of our country expected to be of global market standard. Due to the above said reason our Indian product required to be of very high quality with respect to size of dimension, fit, tolerance and finish etc.

Technical drawings allows efficient communication among engineers and can be kept as a record of the planning process. Since a picture is worth a thousand words, a technical drawing is a much more effective tool for engineers than a written plan.

Purpose of studying engineering drawing:

• To develop the ability to produce simple engineering drawing and sketches based on current practice
• To develop the skills to read manufacturing and construction drawings used in industry.
• To develop a working knowledge of the layout of plant and equipment.
• To develop skills in abstracting information from calculation sheets and schematic diagrams to produce working drawings for manufacturers, installers and fabricators.

Regardless of branch of engineering the engineering drawing is used. However based on the major engineering branches, engineering drawing can be classified as follows:

Mechanical engineering drawings:

Some examples of mechanical engineering drawings are part and assembly drawings, riveted joints, welded joints, fabrication drawings, pneumatics and hydraulics drawings, pipeline diagrams, keys coupling drawings etc

When, on a drawing, if a part of a line or some lines among many other lines need to be erased or modified, in normal way of erasing will damage the other nearby lines. In such a situation an erasing shield is effectively useful. It is a thin metallic sheet having small openings of different sizes and shapes. A suitable opening is aligned to the line to be erased and the line is removed by the eraser.

Drawingpaper: These are of two types:

• Hand-made paper
• Mill-made paper

Hand-made papers have rough surfaces, pale in colour and not used for regular work, but meant for charts. Mill-made papers are most commonly used for regular work, and are available in different sizes and rolls. They are specified by their weight in kg per ream or density in grams per square meter.

• understand to fold the A1, A2 and A3 size drawing sheets • keep the drawing sheet filing cabinet • filing cabinet to handle according to IS procedure.

Method of folding of printed drawing sheets as per BIS SP:

46-2003 When drawings sheets are in more numbers, they have to be folded and kept in order to save the trace required for preserving them When the drawings are to be released to shop floor for reference during manufacturing of a component

Drawing board is one of the main equipment of Draughtsman. It is used for supporting the drawing paper/tracing paper for making drawings. It is made of well seasoned wood strips of about 25 mm thick or masonite, free from knots and warping. It should be softer enough to allow insertion and removal of drawing pins. Two battens are fastened to the board by screws, in slotted joints. They prevent warping and at the same time permit expansion and contraction of the strips due to the change of moisture in the atmosphere.

It is of ‘T’ shape, made of well seasoned wood. It has two parts., head and blade. One of thr edge of the blade is the working edge. The blade is screwed to this head such that the working edge is at right angle to head 

The standard ‘T’ square are designated as follows with dimensions shown in mm; as per IS:1360-1989.