Surface roughness measurement in our laboratory and workshop

Stainless steel grinded grain 180 or grained 320 must have this surface value is definitely not true! This statement and definition is absolutely wrong!
We perceive surfaces with our natural senses. The comparison rough and finely ground based on personal subjective perceptions. Whether a surface is rough or fine, each person feels differently. Our surface measurements and evaluations are processed according to DIN EN ISO 4288: 1998, as long as they are defined and requested as such in the order.

matchbox friction area measurement

The wellknown surface of a matchbox shows a lot of different measurement values on the same stripe. So it`s quite difficult to make a consist statement about surfaces which are seen and the difference when they are felt and measured.