separate default tolerance for metric and inch start part

[tdx99]

Hi Everyone,

Is there a way to set different default tolerances for metric and inch start parts?

metric part to be:
x +/- 1
x,x +/-,3
x,xx +/-,15

inch part to be:
x.x +/- .02
x.xx +/- .01
x.xxx +/- .005


I can set one or the other in config.pro, but not both.

Thanks in advance.

 

[dr_gallup]

If you are using a template (start part) then the value comes from there, not the config settings. We have separate inch & metric templates, some people have many templates for sheetmetal & other special needs. The config options only affect starting a new empty part. You can load a special config file to change the unit settings.

BTW, it is incorrect to have metric tolerances based on the number of decimal places if you are working to ANSI or ISO drawing standards. Metric does not use trailing zeros to indicate smaller tolerances. See ISO 2768 for one way to handle default tolerances for metric. It's based on choosing a tolerance class (fine, medium, etc.) and then the tol varies with the nominal length. Alternately you can have one default tolerance for all linear dimensions on the drawing.

 

[tdx99]

Dr. Gallup,

Thanks for pointing me in the right direction. We don't have a copy of ISO 2768 but I was able to find some documents online. How would I specify a medium tolerance class? I was wondering if adding "Tolerancing per ISO 2768-m" in the title block would be correct.

 

[dr_gallup]

The official designation of ISO 2768 call out consists of 2 letters.
2768-1 specifies linear and angular dimensions and has 4 letters (f,m,c,v) that specify class.
2768-2 specifies GD&T tolerances and has 3 letters (H,K,L) that specify class.
When applied to a drawing, you need both; ISO 2768-mK would be a valid callout. Note there is a dash between 2768 and the classes.

I would never reference any specification without having a copy of the spec. You need to read and understand everything in the spec or you could get yourself in trouble. In fact, our TS-16959 quality systems requires us to have a copy of every specification called out on every drawing.