Smr (Peak material portion (percentage of material that comprises the peak structures associated with Spk)
Smr1 and Smr2 represent the percentage of surface at the intersection of core surface maximum height and areal material ratio curve, and the percentage of surface at the intersection of core surface minimum height and areal material ratio curve, respectively.
Sk represents the height of the core surface, Smr1 represents the areal material ratio that divides the reduced peaks from the core surface, and Smr2 represents the areal material ratio that divides the reduced valleys from the core surface.
The reduced peaks are the areas that are removed by initial abrasion. Spk represents the average height of the reduced peaks.
The reduced valleys are the areas that hold liquid applied on the surface in order to improve lubricity. Svk represents the average depth of the reduced valleys.
