Which of the following material cannot be machined using ECM? / » Unconventional Machine Process (UMP) solved MCQs / By admin Question: Which of the following material cannot be machined using ECM? A. high strength alloys B. hardened steels C. nonconductive materials D. all of the mentioned Answer» c. nonconductive materials Note: The above multiple-choice question is for all general and Competitive Exams in India.