[Arrath]

> I think it should be up to the wrench owner to make this decision, and not the wrench seller (who collects money for calibrating wrenches).

That would depend on the accreditations involved, yeah? One would certainly hope that the manufacturer goes through a rigorous design and testing process to ensure that the recommended service/calibration interval is accurate and occurs before the tool wanders out of spec for whatever its intended task is.

As the end user you should presumably be able to reasonably adjust that service interval but it should require a similarly rigorous and documented process to determine how much more you can open it up, not just squinting at the wind and saying "eh they over-engineered it so I think we can get 30% more use out of before calibration"

That's where the accreditations and specs come in. If I'm torqueing down a new Ikea bookshelf, I really don't care. New tires at a chain shop? Middling, to the point that they don't over-ugga-dugga my lug nuts on and destroy the bolts. I'm gonna re-tighten them myself after a drive or two anyway. Bolts in a new airliner being tightened down at the plant? You bet I want that shit to be to-spec, and the tools, too.