Tribological assessments have been performed employing a ball-on-disc T-11 tester. The balls were product of metal, whereas the discs were fabricated from metal, aluminium oxide, zirconium oxide, polyamide and poly(methyl methacrylate). The description in the product and the procedures has long been provided inside the literature (Szczerek and Tuszyński in https://albertp481jqw3.onzeblog.com/profile