Certain draughting conventions are used to represent materials in section and machine elements in engineering drawings.
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. The recommended conventions in use are shown below.
When the drawing of a component in its true projection involves a lot of time, its convention may be used to represent the actual component. Figure “Conventional Representation of Machine Components” shows typical examples of conventional representaion of various machine components used in engineering drawing.