An agricultural harvester (10) includes a chassis (12) and a threshing and separating section (24) carried by the chassis (12) that is configured for threshing and separating grain from gathered crop material. The threshing and separating section (24) includes at least one concave (40) with at least one crop engaging surface (98). The agricultural harvester (10) is characterized by a high hardness coating (96) formed on the at least one crop engaging surface (98).