Hi all,
I'm curious as to what the consensus is on dual dimensioning, when the drawing references ASME Y14.5M-1994. I can't find any language in the standard that is specific to allowing or not allowing dual dimensioning. Sections 1.4c and 1.4d both seem to say as much without actually stating that it is not to be used.
"( c) Each necessary dimension of an end product
shall be shown. No more dimensions than those necessary
for complete definition shall be given. The
use of reference dimensions on a drawing should be
minimized.
(d) Dimensions shall be selected and arranged to
suit the function and mating relationship of a part and
shall not be subject to more than one interpretation."
It seems that a drawing listing dual dimensions would require a general note, stating that one of the units of measurement is for reference only. Which in my opinion, would make it useless to dual dimension and only serve to waste space on the drawing. A drawing without this note would allow a manufacturer to cherry pick tolerance conversions and still be correct.