Translations:TechDraw Geometric dimensioning and tolerancing/72/en

From FreeCAD Documentation
Geometric tolerancing reference chart (according to table 2 in ISO 1101-2017)
Type of control Geometric characteristics Symbol Unicode character Datum necessary Notes
Form Straightness
U+23E4
no
Form Flatness
U+23E5
no
Form Roundness
U+25CB
no
In older norms also called circularity.
Form Cylindricity
U+232D
no
Form / Orientation / Location Line profile
U+2312
yes
No datum necessary when used for form purpose
Form / Orientation / Location Surface profile
U+2313
yes
No datum necessary when used for form purpose
Orientation Parallelism
U+2225
yes
Orientation Perpendicularity
U+27C2
yes
Orientation Angularity
U+2220
yes
Location Position
U+2316
yes
No datum necessary when working with norm ISO 5458.
Location Concentricity / Coaxiality
U+25CE
yes
Named concentricity when used for center points and coaxiality when used for median lines. In the norm ASME Y14.5 it was eliminated since the version from 2018.
Location Symmetry
U+232F
yes
In the norm ASME Y14.5 from 2018, the symmetry was eliminated.
Run-out Circular run-out
U+2197
yes
Run-out Total run-out
U+2330
yes