DEVICE AND METHOD FOR FORM ROLLING

PROBLEM TO BE SOLVED: To realize a device and method for form rolling capable of applying form rolling to a thin wall pipe having a circular cross section without breaking the cross sectional shape. SOLUTION: While form rolling face profiles of form rolling rollers 10, 12 and 14 are forced to be different at every form rolling rollers, form rolling faces at every form rolling rollers are forced to be different in the axial direction, the pipe is machined. The pressurizing force of each form rolling roller can be reduced, the total pressurizing force which is applied to the pipe by a form rolling roller group can be reduced, thereby, the form rolling can be conducted while reducing stress applying to the pipe. As a result, the form rolling can be conducted not breaking the cross sectional face of the thin wall pipe.