Polish Mill Assembly Aventus Oil ToolsA PMA A 089 Polish Mill Assembly The A PMA is used to clean out the ID of the Tie Back Receptacle in order to ensure the polished bore receptacle is clean for installing the tie back seal assembly or completion string The Polish Mill Assembly consists of a Top Dress Mill Clean out Mill those are tungsten carbide coated and ground to dimension and a spacer to match the liner top TBR