FRICTION COUPLING

A friction coupling comprising first and second coupling surfaces. A friction surface is provided on the first coupling surface and a counterface is provided on the second coupling surface. The friction coupling further comprises preload elements, such as bolts, for applying a predefined pressure on the first and second coupling surfaces. The friction surface of the coupling comprises abrasive particles that constitute hard asperities which protrude from a substrate of the friction surface with a height h. The abrasive particles are provided on the substrate in a predefined asperity density . The predefined asperity density is greater than a minimum threshold for the asperity density min and is less than 2.5* min. The minimum threshold is defined by the following relationship: min = 4  P H  μ abr 2 h _ 2 + 2 where asperities per unit (surface area) (m−2); P pressure (Pa); μabr coefficient of friction; H hardness (counterface) (Pa) h height (asperities) (m); standard deviation (asperity heights) (m).