Patent ID: 8708120

Claim:
A manufacturing method of a clutch hub configuring a multi-plate clutch together with a plurality of clutch plates splined to the outer periphery, comprising: (a) a step of forming a plurality of spline teeth on the outer periphery of a member having a cylindrical portion, and forming a recessed portion on the inner side of each spline tooth; (b) a step of forming a depressed portion, which is continuously connected to the spline tooth by a bending portion bent from the spline tooth, by depressing one portion of the spline tooth to the inner side by pressurizing from the outer side in the radial direction of the cylindrical portion on one end side of the cylindrical portion; and (c) a step of forming a weir portion at one end of the recessed portion by cutting the bending portion therebetween, with one portion of the bending portion in the spline teeth side remaining connected to the spline tooth, by moving a punch from the outer side to the inner side in the radial direction of the cylindrical portion.