труднообрабатываемый материал difficult-to-cut material, difficult-to-machine material; hard-to-cut material, hard-to-machine material; material of low-machinability rating; heavy-duty material; poor machinability material; problem material; tough material, tough-to-machine material
труднообрабатываемый металл tough metal; hard-to-machine metal
труднообрабатываемый на станке difficult-to-machine