I'm working on a part which has a recess diameter of 88.04 (+0.1, +0.3)mm. The adjacent flat surface must (because I want to understand the shenanigan) match the equivalent profile tolerance with the (U) option.
(Sorry for image quality, some number "3" look like number "2")
Is it possible to put a negative value with the (U) so it matches the diameter tolerance?
Regards,
Assuming the dimensioning and tolerancing standard in use is ASME Y14.5-2018 - Unilateral Profile tolerances start (defined from location) at the nominal location of the surface specified variation. There is not any reference to a - (negative) unilateral Profile tolerance within the standard.
By default, Profile tolerances are bilateral equal unless otherwise specified.
If the specification was 0.2 U 0 then the profile tolerance boundaries would be located starting at the nominal minus all 0.2 to the inside of that surface.
If the specification was 0.2 U 0.2 then the profile tolerance boundaries would be located starting at the nominal plus all 0.2 to the outside of that surface.
U = circle U
See:
ASME Y14.5-2018 Figure 11-31 and and referenced paragraphs
ASME Y14.5-2018 Figure 11-2 and paragraphs 11.3.1.2, 11.2.1.1
ASME Y14.5-2018 Figure 11-3 and referenced paragraphs
ASME Y14.5-2018 Figure 11-4 and referenced paragraphs
ASME Y14.5-2018 Figure 11-5 and referenced paragraphs