Roller burnishing

Roller burnishing differs from abrasive surface finishing techniques in that material is displaced rather than removed.

A surface finish of less than Ra 0.1 μm is achievable with roller burnishing.

A dual roller (cylindrical) tool is moved into the thrust bearing journal of a crankshaft, while the crankshaft is spinning the tool is indexed (so each roller is perpendicular to the thrust surface while backing each other up) deforming the surfaces.

So the diameters of each roller added together (compensated for elastic deformation) equals the finish dimension of the thrust bearing.

The skiving knives pass first, scraping the inside layer of metal, followed by the burnishing rollers, which cold work the tube to create a mirror surface finish.