To facilitate form rolling so as to shorten a machining time and improve productivity by forming a boot groove to be recessed and projected with a recessed and projected roller having the R shape of its tip part formed to be R shape within a prescribed range.

As a material for a tierod bar, a steel pipe cut to a prescribed length is used, drawing is performed for its shaft part and after a spherical part and a hexagonal part are formed, form rolling is performed by using a recessed and projected roller 33. For a form rolling method, a pair of recessed and projected parts 35 as corner parts are formed in a shat part 27 by a pair of projecting parts 33B provided in both sides of the tip part of the roller 33. A distance between the recessed and projected parts 35 is set equal to the length of the boot groove 34. Then, a recessed part 36 and a projected part 37 are formed for the shaft part 27 by recessed and projected parts 33C formed in the tip part of the roller 33 and the boot groove 4 is formed to be recessed and projected. Thus, because of such formation of the boot groove 34, form rolling is facilitated and performed by one operation.