What instrument is used to check surface finish?

The comparison chart is a valuable tool used to evaluate surface finish by providing a visual representation of different surface roughness standards. This chart allows the operator to compare the finish of a machined part against established benchmarks. By examining the surface characteristics in relation to the chart, one can make an accurate assessment of the quality and smoothness of the surface.

In a machining context, achieving the correct surface finish is crucial for ensuring not only aesthetic qualities but also functional attributes such as wear resistance and lubrication effectiveness. The comparison chart simplifies this process by allowing for easy visual checks without needing complex measurements.

Other instruments such as gauge blocks, steel rulers, and calipers serve different purposes related to measurements of dimensions and flatness but are not specifically designed for evaluating surface finish. This shows how the comparison chart stands out as the appropriate choice for assessing surface quality in manufacturing and machining processes.