ISO default roundness

[rumlyronny]

I'm tearing up my head discussing DWG's these days.

Q: If a diameter feature in a DWG do not contain a specific roundness tolerance, neither a general tolerance for form. What is the allowable roundness then?
ISO 8015 refers to "The Default Principle", but is there an overall principle for roundness if nothing other than the ISO applies? Anyone?


-RR

 

[CheckerHater]

If you scroll little bit above "The Default Principle", you will find what they call "Definitive drawing principle":

5.3 Definitive drawing principle
The drawing is definitive. All specifications shall be indicated on the drawing using GPS symbology (with or without specification modifiers), associated default rules or special rules and references to related documentation, e.g. regional, national or company standards. Consequently, requirements not specified on the drawing cannot be enforced.

So no, no roundness by default. Specify roundness, specify envelope requirement, specify ISO 2768 - don't complain about lack of options.

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[rumlyronny]

Thanks for input. Now I have support for my arguments!
I'm not complaining, just arguing with colleagues under-specifying the drawings.


-RR

 

[CheckerHater]

Just a figure of speech - didn't mean that you are complaining
Good luck with your fight!

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[UchidaDS]

Isn't that the roundness should be with in size tolerance?

 

[Belanger]

UchidaDs -- no, that's not true here because the question is regarding roundness in the ISO system of tolerancing. (No "Rule #1" or "envelope principle" by default, as in ASME.)


John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems