What data is the surface roughness mainly evaluated by?

Height characteristic parameter

Contour Arithmetic Mean Deviation: The arithmetic mean of the absolute value of the contour deviation within the sampling length (lr). In actual measurement, the more measurement points, the more accurate Ra will be.

Profile maximum height: the distance between the peak line of the profile and the bottom line of the valley.

Ra is preferably within the common range of the amplitude parameter.

Spacing Feature Parameters

Average width of outline cells. The average value of the microroughness spacing of the profile within the sample length. The microroughness spacing refers to the length of the profile peaks and adjacent profile valleys on the centerline. In the case of the same Ra value, the Rsm value is not necessarily the same, so the reflection texture will also be different. Surfaces that pay attention to texture usually pay attention to two indicators, Ra and Rsm,

The Rmr shape feature parameter is represented by the contour support length ratio, that is, the ratio of the contour support length to the sampling length.

The contour support length is the sum of the section lengths obtained by intersecting the contour with a line parallel to the midline and at a distance c from the peak line of the contour within the sampling length.