Dimensioning precision for dimensions of size and of location. ANSI Y14.5M-2009

[Willmsy]

I was taught that when dimensioning a print, features of size were .XX and feature locations were .XXX
Is this in the standard or is it more of a preference?

Thanks.

[Kelly_Bramble]

I was taught that when dimensioning a print, features of size were .XX and feature locations were .XXX
Is this in the standard or is it more of a preference?

Thanks.

No... not in the standard. Sounds like some kind of tribal knowledge - never learned what a mechanical tolerance is thing to me. Chapter 2, ASME Y15.5-2009 outlines proper dimensional specification in regards to significant figures.

Mechanical tolerances are determined and then specified by understanding an end item or features functional requirement. We don't assign tolerances or significant figures based on the general type of feature. Sometimes manufacturing process tolerance capabilities do take a precedence when the process capabilities far exceed the functional requirements.

[Willmsy]

Thanks, I appreciate the quick response.