Geometric tolerance difference

[s_pme20]

Hi All,

not related to pro-E..but related to general drawing.
I am always confused about geometric tolerance symbols.
Can anyone explain me difference between this two:
View attachment 5533

 

[dr_gallup]

In the first place, the maximum material condition modifier is no valid with concentricity so neither is valid.



If for the sake of argument we change the callout to true position instead of concentricity then we can discuss the difference.



In the first case the M modifier is applied to the feature tolerance so
as that feature deviates from the max material condition the position of
the feature gains bonus tolerance.



In the second case the M modifier is applied to the datum so as the
datum deviates from the max material condition the position of the
feature gains bonus tolerance.