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.

Supplements:

Limits, fits and tolerances (ISO and ANSI Systems)

Reference:

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