GD&T Symbol Reference
The 14 geometric characteristics of ASME Y14.5, by category, plus the material-condition modifiers.
| Symbol | Control | Category | Needs datum |
|---|---|---|---|
| — | Straightness | Form | — |
| ⏥ | Flatness | Form | — |
| ○ | Circularity | Form | — |
| ⌭ | Cylindricity | Form | — |
| ⌒ | Profile of a Line | Profile | — |
| ⌓ | Profile of a Surface | Profile | — |
| ⟂ | Perpendicularity | Orientation | Yes |
| ∥ | Parallelism | Orientation | Yes |
| ∠ | Angularity | Orientation | Yes |
| ⌖ | Position | Location | Yes |
| ◎ | Concentricity | Location | Yes |
| ⌗ | Symmetry | Location | Yes |
| ↗ | Circular Runout | Runout | Yes |
| ↗↗ | Total Runout | Runout | Yes |
Modifiers
| Symbol | Modifier | Abbr. |
|---|---|---|
| Ⓜ | Maximum Material Condition | MMC |
| Ⓛ | Least Material Condition | LMC |
| (none) | Regardless of Feature Size | RFS |
| Ⓟ | Projected Tolerance Zone | P |
Build feature control frames and work out bonus tolerance in the GD&T Helper.
A reference aid, not a substitute for engineering judgment. Verify against the governing standard.