Provided is a method of forming a locking ridge for a case of forming the locking ridge on an outer peripheral surface of a joint portion by form rolling, the method realizing a joint portion structure which is superior in pipe detachment prevention performance when pipes with locking ridges are connected by fixing pipe ends with a housing. Using a convex roller arranged inside the workpiece pipe body and a forming circular groove arranged outside the pipe body, the locking ridge is form-rolled such that an upright wall portion thereof is raised at an angle of at least 65 and no greater than 90 with respect to the outer peripheral surface in the pipe axis direction, and that a height of the locking ridge from the outer peripheral surface to the apex of the tip portion is at least a total of curvature radii of faces of the processing means in contact with the pipe body.

Battery pack powered roll groover described herein includes a housing, an inner roller provided on the housing and configured to be received in an inner circumference of a workpiece, a groove roll provided on the housing and configured to produce a groove on the workpiece, one or more motors provided within the housing and configured to drive the groove roll, and an electronic processor electrically connected to the one or more motors. The electronic processor is configured to operate the one or more motors to perform a first operation of moving the groove roll in a radial direction, and operate the one or more motors to perform a second operation of moving the groove roll around a track in a circumferential direction. The first operation is performed to adjust a groove depth on the workpiece. The second operation is performed to produce the groove on the workpiece.

In a die-casting machine with toggle-joint or without toggle-joint, a threaded section or a shaped section of horizontal columns is made by first carrying out turning and then rolling.