Determination of process function for pitch diameter D2 in electro-erosion machining of threads from sintered metallic carbides type G20 - Neagu, Corneliu; Dumitrescu, Andrei; Berinde, Mihaela; Badea, Gheorghe (Annals of ”Dunarea de Jos” University of Galati, Fascicle V, Technologies in machine building, 2009)