[Ja...] Posted February 8, 2023 Share Posted February 8, 2023 I have a part with 4 coplanar surfaces. The print points to one of them and asks for flatness 4x. Does that mean they should be evaluated as one large plane or 4 individual planes? Where can I find this in ASME? There is a separate callout pointing to one of 20 coplanar features that says parallelism .5 typ. If it is typical, does that mean they are each evaluated separately or as one. Can I find that in ASME? Link to comment Share on other sites More sharing options...
[Jo...] Posted February 8, 2023 Share Posted February 8, 2023 Flatness is a form control, and is applied to each surface. Being a total width without orientation, the multiple surfaces are only controlled in respect to each other by default feature of size tolerance, or a profile requirement to refine orientation and location to Datum (and each other). It sounds like the designer has understanding of this by indicating multiple flatness zones. Link to comment Share on other sites More sharing options...
[Er...] Posted February 9, 2023 Share Posted February 9, 2023 In my experience... If all were to be measured as one there would be no "modifer" of the dimension. Question 1 4x would be 4 seperate and independent plane measurements back to the datum. I would report 4 Characteristics. Section 1.7.4.1 Section 1.9.5 Question 2 The "typ" is old school. Some would say laziness. Our customers often do thier own mix of the standard and what they want to do. I would report 20 Caracteristics. Link to comment Share on other sites More sharing options...
[Ja...] Posted February 10, 2023 Author Share Posted February 10, 2023 If "4x would be 4 separate and independent plane measurements" then how should the print be if they did want all 4 of them evaluated as one surface? Link to comment Share on other sites More sharing options...
[De...] Posted February 10, 2023 Share Posted February 10, 2023 In Y14.5, if modified by <CF>, designates continuous feature. This would indicate the overall flatness of the four locations as one feature. Link to comment Share on other sites More sharing options...
[Jo...] Posted February 10, 2023 Share Posted February 10, 2023 Please sign in to view this quote. Y14.5-2018 doesn't explicitly state that CF can be used for flatness. The example cases are: cylindrical, width (feature of size, rule #1), and profile. It also states a note with number of surfaces or times is permitted adjacent to CF symbol. AGI training covers this exact scenario in the basics course under Datum selection and qualification. I cannot post that copyright material. I would at minimum report min max numbers in both cases, by default those are individual tolerance zones unless refined.method.JPGcoplanarity.JPG Link to comment Share on other sites More sharing options...
[Ja...] Posted February 10, 2023 Author Share Posted February 10, 2023 Thanks for all your responses. I believe the intent is for them all to be evaluated in one tolerance zone. I wanted to find verification in ASME. I think I found it. Thank you all. Link to comment Share on other sites More sharing options...
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