New method of thread rolling

The research and implementation works completed in the framework of new thread rolling technology developed for sleeper fixing screws have been described in the present study. Described thread rolling method consists in thread forming by means of two flat wedges provided with special grooves designed for thread forming. The results obtained from numerical simulation of thread rolling process are presented in the study. The calculations have been completed using finite volumes method (FVM) and finite element method (FEM). Furthermore experimental tests consisting in thread forming on the bars made of commercial lead in laboratory conditions and results of industrial tests with simultaneous thread forming on two screws have been described.