What is Projection?

Any object has three dimensions, viz., length, width and thickness. A projection is defined as a representation of an object on a two dimensional plane. The projections of an object should convey all the three dimensions, along with other details of the object on a...
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Representation of Threads

The true projection of a threaded portion of a part consists of a series of helices and it takes considerable time to draw them. Hence it is the usual practice to follow some conventional methods to represent screw threads. Screw thread nomenclature figure below shows the...
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Designation and Relative Positions of Views

An object positioned in space may be imagined as surrounded by six mutually perpendicular planes. So, for any object, six different views may be obtained by viewing at it along the six directions, normal to these planes. Figure “Designation of the views” shows an object...
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Importance of Dimensioning in Machine Drawing

A drawing of a component, in addition to providing complete shape description, must also furnish information regarding the size description. These are provided through the distances between the surfaces, location of holes, nature of surface finsih, type of material, etc. The expression of these features...
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Drawing Conventional Representation

Certain draughting conventions are used to represent materials in section and machine elements in engineering drawings. Materials As a variety of materials are used for machine components in engineering applications, it is preferable to have different conventions of section lining to differentiate between various materials....
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Drawing Sections

In order to show the inner details of a machine component, the object is imagined to be cut by a cutting plane and the section is viewed after the removal of cut portion. Sections are made by at cutting planes and are designated by capital...
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Principles of Drawing

Engineering drawings are to be prepared on standard size drawing sheets. The correct shape and size of the object can be visualized from the understanding of not only the views of it but also from the various types of lines used, dimensions, notes, scale, etc. To provide...
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Classification Of Drawings

Machine Drawing It is pertaining to machine parts or components. It is presented through a number of orthographic views, so that the size and shape of the component is fully understood. Part drawings and assembly drawings belong to this classification. An example of a machine...
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