When you have different manufacturing facilities you will always have this issues even when you are building to the same spec.
Your manufacturing process will have different tolerance biases that&#x27;s unavoidable.
The problem happens when you stack tolerances in an additive manner for example when you have a nut which is built to spec in plant one and is 0.005% too big (which is well within the tolerance limit) and you have the bolts built in plant 2 and they come out 0.005% too small (which on their own is still within the spec) you get an overall tolerance shift of 0.01% which all of a sudden is out of spec.
This just happens in manufacturing all the time the parts are in spec individually but the end result just doesn&#x27;t work.<p>I actually deal with this all the time in hobby electronics you buy various parts which all of them have a spec with +- certain percent and you when you buy them from a single batch you can be quite out of luck and find out that when you add them all together the tolerances just stack against your initial design.