Thread rolling is a chipless cold forming process.A plain cylinderical blank,with a diameter part way between the major and minor diameters of the finished thread,is rotated and squeezed between cylinderical type hardened steel dies whose working surfaces are the reverse of the thread form to be produced.The threads of the die penetrate the surface of the blank as it rolls between them,diplacing material to form the roots of the threads,and forcing the displayed material radially outward to form the crests.UNLIKE OTHER THREADING PROCESS, NO MATERIAL IS WASTED.