Strictly adhering to ISO 2768 standards,
ensuring perfect fit for every part

What is ISO 2768?

ISO 2768 is an international standard that defines general tolerances for linear dimensions, angular dimensions, and geometrical features without specific tolerance indications. It ensures consistency and quality in manufacturing parts and assemblies.

ISO 2768-1

Tolerances for linear and angular dimensions.
Grades:
f (fine): Fine tolerances for high precision.
m (medium): Medium tolerances for general precision.
c (coarse): Coarse tolerances for lower precision.
v (very coarse): Very coarse tolerances for very low precision.

ISO 2768-2

Geometrical tolerances (flatness, straightness, perpendicularity, etc.).
Grades:
H (high precision): High precision for features with stringent requirements.
K (medium precision): Medium precision for general requirements.
L (low precision): Low precision for less stringent requirements.

Linear Dimensions

Permissible deviations in mm for ranges in nominal lengthsTolerance class designation (description)
f (fine)m (medium)c (coarse)v (very coarse)
0.5 up to 3±0.05±0.1±0.2-
over 3 up to 6±0.05±0.1±0.3±0.5
over 6 up to 30±0.1±0.2±0.5±1.0
over 30 up to 120±0.15±0.3±0.8±1.5
over 120 up to 400±0.2±0.5±1.2±2.5
over 400 up to 1000±0.3±0.8±2.0±4.0
over 1000 up to 2000±0.5±1.2±3.0±6.0
over 1000 up to 2000-±2.0±4.0±8.0
CNC machining parts Linear Dimensions Example

External Radius and Chamfer Heights

Permissible deviations in mm for ranges in nominal lengthsTolerance class designation (description)
f (fine)m (medium)c (coarse)v (very coarse)
0.5 up to 3±0.2±0.2±0.4±0.4
over 3 up to 6±0.5±0.5±1.0±1.0
over 6±1.0±1.0±2.0±2.0
Example of external radius and chamfer heights for CNC machining parts, demonstrating curved and angled edges

Angular Dimensions

Permissible deviations in degrees and minutes for ranges in nominal lengthsTolerance class designation (description)
f (fine)m (medium)c (coarse)v (very coarse)
up to 10±1°±1°±1°30'±3°
over 10 up to 50±0°30'±0°30'±1°±2°
over 50 up to 120±0°20'±0°20'±0°30'±1°
over 120 up to 400±0°10'±0°10'±0°15'±0°30'
over 400±0°05'±0°05'±0°10'±0°20'
Sample of angular dimensions for CNC machining parts, indicating angles between features of the part

Straightness and Flatness

Ranges in nominal lengths in mmTolerance class
HKL
up to 100.020.050.1
over 10 up to 300.050.10.2
over 30 up to 1000.10.20.4
over 100 up to 3000.20.40.8
over 300 up to 10000.30.61.2
over 1000 up to 30000.40.81.6
Sample of straightness and flatness measurements for CNC machining parts, ensuring precision in geometry

Perpendicularity

Ranges in nominal lengths in mmTolerance class
HKL
up to 1000.20.40.6
over 100 up to 3000.30.61
over 300 up to 10000.40.81.5
over 1000 up to 30000.50.82
Example of perpendicularity for CNC machining parts, ensuring that surfaces or features are at a right angle to each other

Symmetry (Position for ISO G&T Standard not-ASME or ANSI GD&T)

Ranges in nominal lengths in mmTolerance class
HKL
up to 1000.50.60.6
over 100 up to 3000.50.61
over 300 up to 10000.50.81.5
over 1000 up to 30000.512
Sample of symmetry and position for CNC machining parts based on ISO G&T standards, not ASME or ANSI GD&T

Circular Runout

Ranges of nominal lengths in mmTolerance Class
HKL
0.10.20.5
Sample of circular runout measurement for CNC machining parts, ensuring minimal deviation in circular geometry

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