4.1 MECHANICAL DRAWING TECHNICAL LANGUAGE: DRAWING AND TOOLS Drafting Technical drawing, or drafting, can be considered a universal language used to visually communicate technical information that must be precise, accurate, and understandable. Its purpose is to information on how an object is made or how it works. The starting point of any engineering operation is the drawing, which is used by technicians and operators as the basis of the planning process for the design and through to the production of an item or a component. To make drawings precise and clear, every geometric element has to be represented in a way that respects standardised conventions such as size, scale, and the types of lines. convey 1 DO Can you list four geometric elements of a plane figure? 1 Types of lines , and shape define the types of lines used to create a technical drawing. The most common are: Thickness, width : thin, continuous lines used for section views, dimensions, and projections. Section lines : thick, continuous lines used for visible . Thick lines outlines : dashed lines to visualise hidden details. lines Dashed : thin lines that extend from the edge of the drawing and define the dimension of a specific part. Extension lines : thin lines (between two extension lines) with an on each end to indicate the extent and direction of the dimension of a section. Dimension lines arrow Drawing tools Technical drawings are usually , creating what’s known as a freehand sketch before being reproduced by a computer-aided system. Some of the basic tools used by are: hand-sketched draftsmen : this can have a specific format, texture, and thickness. Paper : they have a graphite and can draw lines of constant width . Mechanical pencils lead 1 : this is a professional desk suitable for large sheets of paper. Drafting table : this is used to draw lines at a right angle (90°). Set-square : this is used to draw horizontal lines on a drafting table. T-square : this is used to inscribe arcs or circles. Compass : this is used to measure angles. Protractor MORE On wooden pencils, the ‘H’ stands for hardness, the ‘B’ stands for blackness. 1