How is precision measured in machining?

Precision in machining is measured by using accurate measuring tools to gauge dimensions within specified tolerances. This approach ensures that the machined parts meet the required specifications and fit correctly together in an assembly or system. Tools such as calipers, micrometers, and gauges are essential in determining the exact measurements of a component and verifying that they fall within the acceptable range of tolerances.

The use of these measuring tools allows for the objective assessment of dimensions and facilitates the ability to repeat processes with high reliability. Ensuring precision through accurate measurements is crucial in machining because even the smallest deviations can lead to significant issues in functionality, performance, and safety of the final product.

Visual inspection, as mentioned in the other options, while useful for assessing surface finish or overall quality, does not provide the quantitative data necessary to confirm precise dimensions. Similarly, calculating the time taken for machining and comparing against a standard without measurement tools does not directly address the need for dimensional accuracy, which is essential in precision machining.