ISO 8062 and ISO 2768 for one dimension

[MaciejM]

Hi everyone,

I have a drawing of a cast plate, and on this drawings there is a dimension for both cast and machined features. I want measure this 53,9 distance from a cast hole to a machined face. Should I add tolerances CT9 (±1) from ISO 8062 and from ISO 2768mK (±0,3), or just stick to CT9?

 

[jassco]

What is CT9? Is it a tolerance grade? Your machined surface seems too small to locate the hole, or vice versa.

 

[Burunduk]

Why do you want to use any of these redundant standards?
Just apply the tolerances that will make it work.
What are the functional considerations?
Does the flat surface locate the part in the vertical direction or the hole? The one that does should be a datum feature of some order, probably not the primary bacause they both are too small to orient the part. Choose a datum reference frame that makes sense for constraining all relevant degrees of freedom. The distance dimension should be basic. Then if the hole is controlled from the flat end use position, or if the flat end is controlled from the hole use profile. Maybe they both should be dimensioned and controlled relative to something else and then none of them is a datum feature. Their distance from each other would result from both their location tolerances. Assign the tolerance values as wide as your design can tolerate. Good luck, and get rid of those silly general +/- standards.