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ISO 2768-2 Perpendicularity Tolerances Table

This page provides the general perpendicularity tolerances according to ISO 2768-2:1989. These geometrical tolerances typically apply to parts produced by material removal processes (turning, milling, drilling, etc.) when no individual geometric tolerances are specified on the drawing.

The table below gives the permissible perpendicularity deviations for right-angled surfaces, based on the nominal length of the shorter side forming the right angle.

Perpendicularity tolerance values (ISO 2768-2)

Perpendicularity tolerances for ranges of nominal lengths of the shorter side (mm)
Perpendicularity tolerances for ranges of nominal lengths of the shorter side (mm)
Tolerance class up to 100 mm over 100 mm
up to 300 mm 		over 300 mm
up to 1000 mm 		over 1000 mm
up to 3000 mm
H 0.2 0.3 0.4 0.5
K 0.4 0.6 0.8 1.0
L 0.6 1.0 1.5 2.0

Note: All values are in millimetres (mm).

When applying these perpendicularity tolerances, the longer of the two sides forming the right angle shall be taken as the datum.

When to use ISO 2768-2 perpendicularity tolerances

ISO 2768-2 perpendicularity tolerances are used for features without individual tolerance indications. They provide a simple, standardized way to control perpendicularity in general-purpose machining and fabrication, without crowding the technical drawing with separate geometric tolerances for every feature.

In practice, they are well suited for components where moderate accuracy is sufficient, such as brackets, simple housings, plates and structural parts, provided that no tighter functional requirements are specified.

Key terms and definitions

Perpendicularity
Geometrical tolerance specifying how close a surface or axis shall be to 90° with respect to a datum feature.
Nominal length of the shorter side
The basic dimension of the shorter side forming the right angle between two surfaces. This length determines which line in the table applies.
Datum (longer side)
The longer of the two sides forming the right angle, used as the reference (datum) for evaluating perpendicularity.
Tolerance classes H, K, L
Standard tolerance classes defined in ISO 2768-2, where H is the tightest and L is the largest (coarsest) general tolerance for perpendicularity.

For a complete list of ISO and ANSI standards, charts and calculators for limits, fits, allowances and tolerances, see the limits, fits and tolerances (ISO and ANSI systems) overview .

Reference

  • ISO 2768-2:1989 – General tolerances – Part 2: Geometrical tolerances for features without individual tolerance indications.