Engineering Drawing

General Assembly Drawings

An assembly drawing (see Figure 1) represents the relative position and/or shape of a group of assembled parts. It also depicts the constituents of a parts list.
A list of parts is often provided in a separate document, i.e. a parts list, but can be included within the drawing if space permits. The individual parts are annotated with ballooned numbers these will match the item numbers in the parts list. Relevant information can also be added, torque settings can either be shown adjacent to the item balloon or in a torque table, other information, e.g. lubricating grease and thread adhesive can be shown alongside corresponding flag notes. Overall and key dimensions are usually included where appropriate, along with mass and centre of gravity information. Take note that Figure 1 is half sectioned, this is permissible when an assembly is symmetrical around its central axis. If the assembly is asymmetric, a full section of the assembly may needed to show detail.

Detailed Parts / Manufacturing drawings

A part drawing includes all the necessary information required for the complete and unambiguous definition of the part, e.g. material properties, dimensions, tolerances, surface texture (see Figure 2).

Fabrication drawing

A fabrication drawing depicts a work-piece which is permanently joined together by means of welding, brazing, adhesion or other method. The constituents need to be fully specified. A parts list can be included on the drawing if space allows along with simple profile cut lengths (see Figure 3).

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