ISO 2768-2 STRAIGHTNESS FLATNESS TOLERANCES TABLE


The general tolerances table on straightness and flatness according to ISO 2768-2. Dimensions mainly applies to the parts that are produced by material removal.

If general tolerances in accordance with ISO 2768 shall apply, ISO 2768 followed by the tolerance class (f, m, c, v) in accordance with ISO 2867-1 and then tolerance class (h, k, l) per ISO 2867-2 (Ex:ISO 2768-mk) shall be indicated in or near the title block.


General Tolerances on Straightness and Flatness
Tolerance Class up to 10 over 10
up to 30
over 30
up to 100
over 100
up to 300
over 300
up to 1000
over 1000
up to 3000
H 0.02 0.05 0.1 0.2 0.3 0.4
K 0.05 0.1 0.2 0.4 0.6 0.8
L 0.1 0.2 0.4 0.8 1.2 1.6

Note: Values in millimetres


When tolerance is selected, the tolerance shall be based on the length of the corresponding line for straightness and on the longer lateral length of the surface or diameter of the circular surface for flatness.


Reference:

  • ISO 2768-2 (1989) General Tolerances - Part 2: Geometrical tolerances for features without individual tolerance indications