Flatness vs. Profile
Flatness vs. Profile
(OP)
I am looking over a drawing. I have review Y14.5 1994, but I am still confused.
I thought flatness can only be applied to a single surface and profile should be used for multiple surfaces.
The drawing I am reviewing has Datum A applied to sever co-planar surfaces and has a flatness call out.
Can a flatness call out be applied to multiple surfaces? If need be I can send a picture.
I thought flatness can only be applied to a single surface and profile should be used for multiple surfaces.
The drawing I am reviewing has Datum A applied to sever co-planar surfaces and has a flatness call out.
Can a flatness call out be applied to multiple surfaces? If need be I can send a picture.





RE: Flatness vs. Profile
Dave D.
www.qmsi.ca
RE: Flatness vs. Profile
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RE: Flatness vs. Profile
If you have ASME Y14.5M-1994, look at Figure 6-21. This this what they are trying to do?
Note how they use datums A and B together as the primary datum.
RE: Flatness vs. Profile
You are correct that to get the equivalent of flatness for a multi surface datum then profile of a surface is the correct control. Exactly how this is applied/used can vary slightly depending if all the nominally coplaner surfaces are used to make the datum or if only some of them are used. Look at section 6.5.6, although it sounds like you already have.
KENAT,
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