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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.

Main Types of Engineering Drawing

Engineering drawing is used in all branches of engineering. However, based on major engineering fields, it can be classified into the following types:

1. Mechanical Engineering Drawings:

These drawings are related to machine parts and assemblies used in mechanical engineering.

Drawing Paper

Drawing Paper is an essential material used in engineering drawing. It is mainly classified into two types:

• Hand-made Paper
• Mill-made Paper

Hand-made papers have rough surfaces and are pale in color. They are generally not used for regular drawing work but are suitable for charts. Mill-made papers are widely used for regular work and are available in different sizes and rolls. These papers are specified by their weight (kg per ream) or density (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

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.

It serves the functions of a Tee square, set square, protractor and scale. They come in different sizes and a pattern called ‘Pantagraph’ type. It is fitted on the top left side, edge of the drafting board, mounted on an adjustable frame or table. It requires large area of working place. The angle of the drafting board can be adjusted by pedal operating system. There are two counter weights to balance the angular position of the board and the drafting head. It is more suitable for production drawing office.

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.

It has a knee joint in one leg that permits the insertion of pen or pencil point or attaching lengthening bar with pen or pencil point attached to it. It is used for drawing large circles/arcs also for taking large measurements. The pin on the other leg can be swivelled to vertical position when drawing large circles, while drawing the circles of arcs it should be held in such a way that the needle point leg and pencil point leg should be bent so as to make perpendicular to the paper.

बड़ा डिवाइडर एक महत्वपूर्ण ड्रॉइंग उपकरण है जिसका उपयोग माप (dimensions) को स्थानांतरित (transfer) करने तथा रेखाओं को समान भागों में विभाजित करने के लिए किया जाता है।