Loadframe255

ISO 2768 Part 1 is intended to simplify drawing indications and it specifies general tolerances for linear and angular dimensions without individual tolerance indications in four tolerance classes. It applies to the dimensions of parts that are produced by metal removal or parts that are formed with sheet metal fabrication.

ISO 2768 Part 1 only applies to the following dimensions which do not have an individual tolerance indication:

• ISO 2768-2:1989 General tolerances — Part 2: Geometrical tolerances for features without individual tolerance indications. This standard has been revised by ISO. This part is intended to simplify drawing indications and specifies general tolerances in three tolerance classes. It mainly applies to features which are.
• EXAMPLE IS0 2768-mk of In this case the general for angular dimensions in ac- cordance with IS0 2768-l do not apply to right angles (900), which are implied but not indicated, because this part of IS0 2768 specifies general tolerances on perpendicularity.

Doug, there are 2 parts to ISO 2768.1 refers to tolerances for linear and angular dimensuons without tolerance indications and -2 refers to geometric tolerances for features with individual tolerance indiscations. So, in -2 you'll see that K is a tolerance class. ISO 2768-1:1989 General tolerances — Part 1: Tolerances for linear and angular dimensions without individual tolerance indications. Buy this standard This standard was last reviewed and confirmed in 2017. Therefore this version remains current. General tolerance ISO 2768 does not specify where to use these tolerances. Tolerance class is defined as per design requirements and manufacturing capability. For example: for sheet metal parts ISO 2768–mk is used. And for machined components ISO 2768–fh can be used. ISO 2768-2: 1989, General tolerances — Part 2.

a) linear dimensions (e.g. external sizes, internal sizes, step sizes, diameters, radii, distances, external radii and chamfer heights for broken edges);

b) angular dimensions, including angular dimensions usually not indicated, e.g. right angles (90°). unless reference to ISO 2768-2 is made, or angles of uniform polygons;

c) linear and angular dimensions produced by machining assembled parts.

It does not apply for the following dimensions:

a) linear and angular dimensions which are covered by reference to other standards on general tolerances;

b) auxiliary dimensions indicated in brackets;

c) theoretically exact dimensions indicated in rectangular frames.

Note:

1. These tolerances may be suitable for use with materials other than metal.

2. When selecting the tolerance class, the respective customary workshop accuracy has to be taken into consideration.

3. Smaller or larger tolerances should be indicated adjacent to the relevant nominal dimensions.

4. General tolerances specified in angular units control only the general orientation of lines or line elements of surfaces, but not their form deviations.

5. If general tolerances in accordance with ISO 2768 shall apply, the information shall be indicated in or near the title block, such as ISO 2768-m.

Iso 2768-mk Vs Iso 2768-mh

• Angular Dimension
• External Radius and Chamfer height
• Geometric Tolerance such as straightness, flatness, perpendicularity, symmetry and runout.

General Tolerance : ISO 2768

Linear DimensionsNominal Length Range in mmTolerance Classf
(fine)m
(Medium)c
(coarse)v
(very coarse)0.5 up to 3±0.05±0.1±0.2-3 up to 6±0.05±0.1±0.3±0.53 up to 30±0.1±0.2±0.5±130 up to 120±0.15±0.3±0.8±1.5120 up to 400±0.2±0.5±1.2±2.5400 up to 1000±0.3±0.8±2.0±4.01000 up to 2000±0.5±1.2±3.0±6.02000 up to 4000-±2.0±4.0±8.0External Radius and Chamfer HeightsNominal Length Range in mmTolerance Classf
(fine)m
(Medium)c
(coarse)v
(very coarse)0.5 up to 3±0.2±0.2±0.4±0.4over 3 up to 6±0.5±0.5±1.0±1.0over 6±1.0±1.0±2.0±2.0

Iso 2768-mk Vs Iso 2768-mh

Angular DimensionsNominal Length Range in mmTolerance Classf
(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°50'±0°50'±0°10'±0°20'Straightness and FlatnessNominal Length Range in mmTolerance ClassHKLup to 100.020.050.1over 10 up to 300.050.10.2over 30 up to 1000.10.20.4over 100 up to 3000.20.40.8over 300 up to 10000.30.61.2over 1000 up to 30000.40.81.6PerpendicularityNominal Length Range in mm

Iso 2768-mk Standard Free Download

Tolerance ClassHKLup to 1000.20.40.6over 100 up to 3000.30.61over 300 up to 10000.40.81.5over 1000 up to 30000.50.82SymmetryNominal Length Range in mmTolerance ClassHKLup to 1000.50.60.6over 100 up to 3000.50.61over 300 up to 10000.50.81.5over 1000 up to 30000.512

Iso 2768 Mk

RunoutHKL0.10.20.5

Iso 2768 Mk Tolerance Table

Read this article for details on Limit Fit and Tolerance.