Last updated 10 August 2026
Orientation, location and runout controls require at least a primary datum. Form controls take none at all. Profile controls take datums when the profile is located and stand alone when it is not.
The table below is the whole active set from Y14.5-2018, with what each frame may legally carry: whether a datum is required, forbidden or optional, whether a diametral zone applies, and whether a material condition modifier is allowed at all.
Concentricity and symmetry are not in it, because the 2018 standard removed them. The same data is published as JSON at /data/gdt-controls.json with the governing clause for each rule, free to use with attribution.
| Symbol | Control | Family | Datum | Diametral zone | Modifier |
|---|---|---|---|---|---|
| ⏤ | Straightness | Form | not allowed | not allowed | not allowed |
| ⏥ | Flatness | Form | not allowed | not allowed | not allowed |
| ○ | Circularity | Form | not allowed | not allowed | not allowed |
| ⌭ | Cylindricity | Form | not allowed | not allowed | not allowed |
| ⌒ | Profile of a line | Profile | optional | not allowed | not allowed |
| ⌓ | Profile of a surface | Profile | optional | not allowed | not allowed |
| ⊥ | Perpendicularity | Orientation | required | allowed | allowed |
| ∥ | Parallelism | Orientation | required | allowed | allowed |
| ∠ | Angularity | Orientation | required | allowed | allowed |
| ⌖ | Position | Location | required | allowed | allowed |
| ↗ | Circular runout | Runout | required | not allowed | not allowed |
| ⌰ | Total runout | Runout | required | not allowed | not allowed |
Open the tool · the same data as JSON
ASME Y14.5-2018 geometric characteristics and feature control frame legality. ASME Y14.5-2018. CC-BY-4.0, attribute to ctrlPlanner.
This checks one frame. ctrlPlanner keys the whole print, keeps every frame intact through the control plan, and carries them onto the AS9102 forms.
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