Separate Requirements at MMB

In this Question Line video, Jason answers the following question regarding separate requirements at MMB: 

I saw a YT video, from someone I trust, where it was said that to use separate requirements you MUST have at least one of the datums referenced at MMB. I don’t see this explicitly stated in the Y14.5-2009 standard, but separate requirements are not referred to in the RMB section. However, Fig 4-41 shows an example, and the datum is not referenced at MMB, although the tolerance is at MMC. Can I use separate requirement on a FCF if no datum is at MMB?

In this video, Jason explains that simultaneous requirements apply when more than one feature control frame has the same order of datums and same modifiers, requiring those features to be checked simultaneously—unless the “separate requirements” note is applied. He walks through a couple of examples discussing reasons for allowing simultaneous requirements to take precedence or use the separate requirements note, and also explains what happens when the MMB modifier is incorporated. 

For more information on the MMB modifier, check out this additional Question Line video: When to Use MMC and MMB 

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