Surface roughness classification for castings

The proper functioning of a machined part is in many instances largely dependent on the quality of its surface. Engineering properties such as fatigue, hardness and heat transfer are affected by surface finish. Several devices have been developed to measure surface roughness (Amstead et al. 1987). The simplest procedure is a visual comparison with an established standard, while the most commonly used method is to employ a diamond stylus to trace over the surface being investigated and to record a magnified profile of the irregularities. These are generally time-consuming processes, demanding expensive human intelligence.