On the basis of metallography theory and rigidity theory, specimen model was founded to research the metallurgy combination result of knife-edge and basis material and hardness of die knife-edge surface. Martensite was the primary metallographic structure of welding wire.The transition area structure of welding wire and basis material was even. It is in line with stamp requirement that surface HRC of welding specimens should be between 44 and 61. The result show that instituted machining technics of cutting die knife-edge have been satisfied with nonmetallic material cutting.