"精加工精确度" can be translated into English as "precision of finish machining" or "accuracy of fine machining".
"Precision" emphasizes the consistency and repeatability of the measurements or dimensions achieved in the machining process.
"Accuracy" highlights how closely the machined part matches the intended or specified dimensions.
"Finish machining" or "fine machining" refers to the final stages of machining where high precision and surface quality are required.
Both translations are acceptable, and the choice between them may depend on the specific context or emphasis desired.