tolerance

name

symbol

explain

Controls the shape
of the part itself,
without involving datums

Shape tolerance

Straightness

Control the curvature

of a line or axis

Flatness

Control the flatness

of a surface

Roundness

Control the uniformity

of the cross-section circle

Cylindricity

Controls the roundness and

straightness of the cylinder as a whole

Line profile

Control the consistency of a cross-sectional profile with the theoretical shape

Surface profile

Control the conformity of the entire surface profile to the theoretical shape

Classification

name

symbol

explain

Control the angular relationship
between part features and datums

Position tolerance

Directional

Parallelism

Controls features to maintain a
constant distance from a datum

perpendicularity

Control feature is 90°
to the datum

angularity

Controls the feature to be
at a specified angle to the datum

Positioning

Coaxiality

Controls whether the circle
or axis is consistent

Control the correct position of
part features relative to datums

Symmetry

Controls the symmetry of the feature
sides about a reference line

Position

Controls the positional
offset of a hole or feature center

Runout

Circular Runout

Controlling eccentricity errors
during local rotation

Control the runout error of rotating parts
(affecting running accuracy)

Total Runout

Control the eccentricity error
of the entire rotating surface
(including axial and radial)