Overhauls and adjustments

[jban5]

I have a decent basic understanding of what is done originally to a movement to make it a chronometer. Not an expert one but basic.

I wonder about a watch that is originally touted as "adj 5 pos plus temp & iso" after it goes through a proper rebuilding. Are the same steps taken by a good watchmaker as the manufacturer did or are those things that were done originally just accepted and the watch movement adjusted with the regulator only?

I hope I am making sense with my question and if anyone wants to clarify what I'm asking I won't take offense.

Thanks

[Tools]

No. The COSC test is only done once and never done again, and is done to a bare movement. (no dial,hands, rotor or case)

If a certified movement has sat very long at the manufacturer it may be completely disassembled, cleaned, oiled, and adjusted before it is fitted to a case.

A good watchmaker, upon an overhaul, will likely test accuracy in 5 positions then set at an optimum point but will not subject the watch to temperature or humidity extremes.