ISO 2768-1 TOLERANCE FOR DIMENSIONS BIGGER THAN 4000 mm 1

No, and it shouldn't even be an issue anymore, since ISO 2768-2 has been withdrawn, and ISO 2768-1 might follow in the future.

New projects should use ISO 22081, which supplies only the rules for a more unambiguous use of general tolerances but no values. It is now up the designer to define sensible general tolerances.

Germermaman said:

It is now up the designer to define sensible general tolerances.

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It's always been up to the designer to define sensible general and specific tolerances.

Unfortunately too many designers don't understand this.

ISO 22081 replaces ISO 2768-2 and not ISO 2768-1. ISO 2768-1 is still valid and can be used in new projects but as said it will most likely withdrawn in near future.

ISO 2769 can be used for general tolerances.
I am not aware of any standard over 4000mm.

Over this dimension, you shall by yourself define the tolerances based on your project requirements.

Regards

Jonny

I don't think there can be hard general rules. It would totally depend on the application and the requirements. Will it be a weldment? A large machined part? Multiple parts bolted together? This is where knowledge of various manufacturing processes and their realistic tolerance capabilities comes in.

stocjon said:

ISO 2769 can be used for general tolerances.

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ISO 2769:1973 is something completely different ("Modular units for machine tool construction").

What you mean is the German standard DIN 2769:2023-04 (that is the most recent). It is meant to be an addition to ISO 22081 and provide tolerance examples, but it is not yet adapted internationally.

germermaman said:

What you mean is the German standard DIN 2769:2023-04

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Yes you are right I misstyped ISO instead of DIN.

ISO 2768-1 is still valid, 2768-2 is withdrawn but still allowed to use (although ISO will not update it anymore).
It is likely ISO 2768-1 will remain for a while longer due to the wide spread use at least in European industry.

As mentioned, a newer standard for general tolerancing is ISO 22081, which with its rules clearly remove ambiguous requirements if properly used. However, this standard is likely very new to suppliers that are more familiar with ISO 2768-1.

The trend in modern functional requirements now is that no reference to ISO 2768 is allowed (at least within my sphere) as it is outdated, not made for modern machining, and most importantly contradicts ISO 8015 general tolerancing with regards to acceptance critera.

rimag said:

The trend in modern functional requirements now is that no reference to ISO 2768 is allowed (at least within my sphere) as it is outdated

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I'd love to have that trend here, because we're using ASME Y14.5 and our drawings are scattered with ISO2768 and lookalike tolerance tables, just because we have a German team who stuck with it and they slap every useless table on every drawing they touch. Which even conflicts with our inhouse standard and CAD guidelines.

Imagine having a pin of 8mm diameter, having only five dimensions and needing an A2 paper because of the general tolerance and co...