A method for manufacturing a ring-shaped member includes preparing a workpiece, pressing a first member against the workpiece to form a depression having a depth in an axial direction in the workpiece, punching out a bottom portion of the depression in the workpiece using a second member, and deforming a circumferential wall in accordance with relative movement between the workpiece and a third member.

A rolling machine has a rolling die 4 that forms a male screw by pressing a steering shaft 14 which is an object to be rolled and plastically deforming an outer peripheral surface of the steering shaft 14 while rotating in contact with the outer peripheral surface of the steering shaft 14, a main spindle 3 inserted into a penetration hole 10 of the rolling die 4 and transmitting a rotation force to the rolling die 4, a key groove and a key which restrict a relative rotation between the rolling die 4 and the main spindle 3, a spiral oil groove 16 provided on an inner peripheral surface of the penetration hole 10 or an outer peripheral surface of the main spindle and extending from one end portion 10b side in an axial direction of the penetration hole in an inner axial direction of the penetration hole.

A rolling machine has a rolling die 4 that forms a male screw by pressing a steering shaft 14 which is an object to be rolled and plastically deforming an outer peripheral surface of the steering shaft 14 while rotating in contact with the outer peripheral surface of the steering shaft 14, a main spindle 3 inserted into a penetration hole 10 of the rolling die 4 and transmitting a rotation force to the rolling die 4, a key groove and a key which restrict a relative rotation between the rolling die 4 and the main spindle 3, a spiral oil groove 16 provided on an inner peripheral surface of the penetration hole 10 or an outer peripheral surface of the main spindle and extending from one end portion 10b side in an axial direction of the penetration hole in an inner axial direction of the penetration hole.

A process for producing bearing ring blanks, or gearwheel ring blanks, or tubular connection-member blanks, comprises the steps of: a) providing a steel tube; b) dividing the tube into a plurality of slugs each having an axial through cavity; c) supplying the slugs to a die assembly of a cold-forming station, the forming station including a punch assembly; and d) subjecting the slugs to contained forward extrusion through the die assembly, wherein the thrust imparted by a pushing member of the punch assembly on a subsequent slug causes passage of a preceding slug through the die assembly, with deformation thereof into a blank, while a restraining member of the punch assembly occupies the axial cavity of the subsequent slug and at least part of the axial cavity of the preceding slug.

A process for producing bearing ring blanks, or gearwheel ring blanks, or tubular connection-member blanks, comprises the steps of: a) providing a steel tube; b) dividing the tube into a plurality of slugs each having an axial through cavity; c) supplying the slugs to a die assembly of a cold-forming station, the forming station including a punch assembly; and d) subjecting the slugs to contained forward extrusion through the die assembly, wherein the thrust imparted by a pushing member of the punch assembly on a subsequent slug causes passage of a preceding slug through the die assembly, with deformation thereof into a blank, while a restraining member of the punch assembly occupies the axial cavity of the subsequent slug and at least part of the axial cavity of the preceding slug.