Cold joining method using plastic flow has been useful for production of joint parts. The high torsional strength of the joint of a disk and a shaft was obtained by plastic flow serration joining, but the axial strength of the joint was not so high. To improve the axial strength, the serration joining was combined with additional upsetting joining. After upsetting joining high residual compressive stresses were induced between the shaft and the disk by a level with the yield stress of the disk material. The initial axial strength of joining of the disk and the shaft increases by 2.5 times by using the combination of upsetting joining and serration joining under a well-rinsed condition.