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It is used to ink the straight lines drawn with the instruments but never for free hand lines or lettering.

The quality of a good drawing does not only depend on the talent of the craftsmen but also on the quality of instruments he uses.

Drawing instruments are generally sold in sets in boxes, but they are also available separately. The main parts of high grade instruments are generally made of nickel or brass. They must be rust proof. Tool steel is used for making the blades of the inking pen, bow instruments and various screws.

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

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.

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.

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.

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.

Drop spring bow pencil and pen : Drop spring bow pencil and pen are designed for drawing multiple identical small circles. Example: rivet holes, drilled/reamed holes. The central pin is made to move freely up and down through the tube attached to the pen or pencil unit. It is used by holding the knurled head of the tube between thumb and middle finger while the index finger is placed on the top of the pin. The pin point is placed on the centre point of the circle to be drawn and pencil or pen is lowered until it touches paper. The instrument is turned clockwise and the circle is drawn.

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.

• 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