The spacing between lines should be uniform. A leader may also be used to indicate a note or comment about a specific area. Tie-rod and pipe joints 4. But whereas the purpose of artistic drawing is to convey emotions or ideas as the viewer interprets the images, the purpose of engineering drawing is to convey the same detailed and unmistakable information to all viewers.
Figure 30 - Example of a directly dimensioned hole. The term "technical data package" TDP is now used to refer to the complete package of information in one medium or another that communicates information from design to production such as 3D-model datasets, engineering drawings, engineering change orders ECOsspec revisions and addenda, and so on.
They are the thickest lines on a drawing and done with a pencil softer than HB. This cross-sectional view section A-A, figure 17one that is orthogonal to the viewing direction, shows the relationships of lengths and diameters better.
These are freehand drawn and only for short breaks. Half-Sections A half-section is a view of an object showing one-half of the view in section, as in figure 19 and Figure 29 - Exampled of a dimensioned hole.
An engineering drawing not only helps convey ideas and convert concepts into reality, an engineering drawing follows criteria and conventions to eliminate confusion by the the standardization of nomenclature and practices, as a way to clearly relay the information to the individual who understands it when it is read, and very importantly, it indicates or hints how something is going to be manufactured.
Engineering drawing, is the most important aspect of mechanical engineering, as it is the fundamental need to develop the design and assembly of a machine.