Creating a Machine Drawing for a Manufacturing Firm
By Ed Salmon
A machine drawing graphically represents the way that a machine
part will be manufactured. To ensure that the drawing has all the
proper information needed for manufacturing, it goes through a four-stage
process: designing, drafting, checking for quality, and evaluating.
Successful completion leads to manufacturing the part (See Figure
In the design stage the designer initiates the process by making
a rough sketch of a particular part that needs to be manufactured.
Suppose, for example, the designer needs a 3-inch-square block with
a 1-inch hole drilled in the center. He or she sketches this part
on a piece of paper. This sketch, however, is not the formal drawing.
A number of people review it before it is accepted and completed.
The drafting stage produces the formal drawing. The draftsperson
uses standard drafting procedures and follows company standards
in order to draw the 3-inch square with a 1-inch hole drilled in
the center. Checking for Quality
In the quality control (QC) stage, the quality control person inspects
the drawing and reviews it for proper use of standard drafting procedures
and company standards. The QC person also determines that the drawing
has all the necessary information for the part to be manufactured.
For example, he or she would reject the drawing if the 1-inch drilled
hole were not located within the proper dimensions. He or she marks
the errors and indicates the corrections on the drawing. The corrected
drawing is sent to the original designer. Evaluating
The designer evaluates the drawing. It must show everything needed
for manufacturing and be free of errors. If the drawing needs more
work, it is sent back to the draftsperson to have the errors corrected.
Once the corrections are made, the drawing goes back to the designer.
If the drawing is acceptable, it is sent to manufacturing. Manufacturing
Manufacturing is the creation of the part based on the information
provided on the completed drawing. The people on the manufacturing
floor use the drawing to set up the appropriate machines and the
production of the 3-inch square block with the 1-inch hole in the
center begins. The drawing is filed for reference.