EML 2322L – MAE Design and Manufacturing Laboratory
Typical Tolerances of Manufacturing Processes
In the past, one of the traditional weaknesses with graduating mechanical
design engineers is their inability to select tolerances. Most students were
reasonably proficient using one or more CAD packages and could produce
drawings which were pretty good (given their limited experience levels).
However, despite knowing how to put a tolerance on a drawing, most
students generally had no idea what the actual numbers should be, or any
sense of what the process for selecting reasonable tolerances might consist of.
Since Geometric Dimensioning and Tolerancing (GD&T) is in widespread
use in industry, the MAE curriculum has changed to include it in EML2023.
Nevertheless, knowing how to properly express a tolerance for cylindricity or
parallelism between two surfaces on a part drawing is not the same thing as
knowing what a reasonable number for that tolerance should be. After taking
EML2322L, the students should be much more proficient in these areas.
To facilitate the students’ understanding of this important area of mechanical
design, we have put together a few slides on some common manufacturing
processes, and what their tolerance producing capability is. After taking
EML2322L, the students should have a tangible understanding of the
tolerances associated with basic manufacturing processes used in this course
(i.e. milling, turning, drilling, reaming, bandsaw cutting, etc.)
