Last updated 10 August 2026
No. Flatness is a form control and takes no datum. A frame with a datum on it is non-conformant under Y14.5-2018 section 6.3.1.
A perpendicularity with no datum looks obviously incomplete, so it gets caught. A flatness with a datum looks entirely reasonable, so it does not, and it is equally wrong. The surface is either flat within the zone or it is not; nothing else on the part enters into it.
If what you actually want is a surface that is flat AND oriented, that is two requirements and it takes two frames, or a profile control that carries both.
| The frame | ⏥|0.005|A |
|---|---|
| Control | Flatness |
| Family | Form control |
| Datum reference | not allowed |
| Diametral zone | not allowed |
| Material condition modifier | not allowed |
| Legal under ASME Y14.5-2018 | no |
Open this case in the calculator, and change the numbers.
Computed by ctrlPlanner. ASME Y14.5-2018.