THREAD FORMING METHOD Russian patent published in 2003 - IPC

FIELD: machine engineering, namely forming thread in parts operating at sign-variable loads in condition of abrasive wear. SUBSTANCE: method comprises steps of finishing and strengthening parts by means of tools electrically heated on part mounted with possibility of rotation. In order to lower working time period, to increase wear resistance and fatigue strength, - before finishing and strengthening thread is forming in such a way that base and lateral surfaces of thread profile are worked simultaneously by means of different tools. First tool has angle of thread less than nominal one and necessary radius of thread indentation near apex; second tool has angle of thread equal to nominal one and it is not used for thermomechanically acting upon base of thread indentation. First tool for forming indentation of thread may be selected according to condition of forming shape and dimension of thread without getting worse of its strength characteristics and demands relating to geometry of the whole thread profile. EFFECT: enhanced fatigue strength and wear resistance of part, shortened time period of forming thread. 1 cl, 2 dwg