Watch Out for the Subtle Difference With Regards to
Datums:
Single Segment Tightens Location -
Composite Doesn't
Although a couple of past Tips have
dealt with composite versus single segment callouts, I
continue to get questions regarding the difference. So, here
we go again.
Single segment simply means that there are
two separate geometric callouts which should be read
independently. Both requirements must be
met.
Composite, on the other hand, is represented
using a single geometric characteristic symbol with multiple
tolerances shown. The primary purpose of the lower segment of
a composite position tolerance is to control the location of
features within a pattern. If any datums are repeated in the
lower segment, they refine the orientation (perpendicularity,
parallelism or angularity) of the pattern relative to the
referenced datums. |
