Tribology is the study of friction, wear and lubrication. This assay is performed with a specifically designed attachment to quantify resistance of materials over a broad range of angular frequency (radians/sec) under a defined downward force (up to 40N) and temperature (5 to 180C).  An example output are Stribeck curves (below) that compare the coefficient of friction (CoF) vs increasing spindle speed for 2 regular and 2 high mileage brand name motor oils at 15, 25, and 125C under 1 Newton downward force.