•Hydrogenated Diamond-Like Carbon was successfully deposited on AISI 52100 steel.•The multi-layered DLC significantly improved adhesion with 72.6 N of critical load.•The wear rate behaves as the applied load does due to a transferred carbon layer.•Hybrid grey-fuzzy reasoning was used to find optimum real work conditions. The amorphous carbon (a-C:H) coating, with interlayer architectures improves adhesion significantly. Because of this, a novel multi-layered a-C:H coating was deposited on an AISI 52100 steel, by PECVD. The coating was characterised using SEM-EDS, Raman, nano-indentation, interferometry and pin-on-plate. In addition, a designed experiment was implemented for the tribological tests. Wear and friction results were analysed using a hybrid grey-fuzzy method to obtain optimum combination of the tribo-parameters.