In Reply to Parent Post by Bill Ryan
Welcome to the Cove
Our normal "practice" is to report one digit further than the callout. We don't have that documented internally but I seem to remember seeing it as a "should" somewhere (I require it for any documentation I may be sending to our customer). You may be, momentarily, "fooling" the customer (and yourself) but if you take variability into account, you could end up shipping product which will cause a "no build" or loss of functionality.
When I was in the high tech aerospace/medical machining business, we made it a policy to cover this issue in Contract Review with the customer before we ever cut metal.
As an aside,
we always discussed the form, fit, and function aspects of a component we made for customers (everything custom to customer's design.)
We found it helpful to request tolerances as either
(+0.000 / -0.xxx) or (+0.xxx / -0.000),
instead of (+/-0.yyy),
depending on the mating part. We had a nice little set of toys to illustrate our point (male mating parts with dimension at maximum material condition and female mating parts the opposite.)
Sometimes the customer's design engineers would have an epiphany and modify ALL their drawings to show tolerances in our suggested method.