[Ja...] Posted June 1, 2020 Share Posted June 1, 2020 I do not have access to the ISO standards, but I am very interested in how ISO defines the material boundary size of a secondary or tertiary datum referenced at MMB/LMB. I think the section in ISO is 4.2.2. Does anybody here have access to 2692 and an idea on how they propose to calculate material boundary size? Link to comment Share on other sites More sharing options...
[SH...] Posted June 3, 2020 Share Posted June 3, 2020 Please sign in to view this quote. Hi, I follow ASME standards and I think your asking about datum shift. I think maximum material boundary or datum shift is the most miss understanding and toughest area in GD&T. If you understand it well you will realise it is a simple concept.If the datum is a bore, datum shift is the radial distance between the maximum material condition of the bore that is the minimum size of the bore and actual radius of the bore. I have attached a YouTube video about this concept by James de meadows (ASME committee member) https://youtu.be/r8CQynVR_Vg Link to comment Share on other sites More sharing options...
[Da...] Posted June 3, 2020 Share Posted June 3, 2020 Just surfing around the net and found out 2692:2020 could happen -> https://www.iso.org/standard/74592.html Link to comment Share on other sites More sharing options...
[SH...] Posted June 3, 2020 Share Posted June 3, 2020 Please sign in to view this quote. Is there is any difference between iso and ASME in material boundary conditions?? I think no. Link to comment Share on other sites More sharing options...
[Ja...] Posted June 4, 2020 Author Share Posted June 4, 2020 Please sign in to view this quote. Datum shift is OK with me, I was just curious to see how ISO calculates material boundaries when datum features are referenced as secondary or tertiary as far as adding higher precedence geometric constraints. Please sign in to view this quote. ISO is very clear when it comes to how to calculate the MMB/LMB and offers a procedural method in doing so in 2692. ASME mentions one way to do it but doesn't offer any alternatives or what to do if the conditions that they pose aren't quite met on your drawing. There is a little room for interpretation with Y14.5 in this regard. Link to comment Share on other sites More sharing options...
[SH...] Posted June 4, 2020 Share Posted June 4, 2020 Please sign in to view this quote. Sorry, I misread your question.. Link to comment Share on other sites More sharing options...
[Da...] Posted June 16, 2021 Share Posted June 16, 2021 Please sign in to view this quote. June 2021 actually -> https://www.iso.org/standard/74592.html Link to comment Share on other sites More sharing options...
[Aa...] Posted June 16, 2021 Share Posted June 16, 2021 Please sign in to view this quote. Agreed. 2692:2006 Section 3.8 says the Maximum Material Virtual Size (MMVS) is generated by the collective effect of the maximum material size and the geometrical tolerance given for that feature. Link to comment Share on other sites More sharing options...
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