A method for press-molding dams in a cylindrical component for holding clutch plates, comprising steps of: preparing a work which comprises a plate portion extended in a radial direction against a rotational shaft, and a cylindrical portion which is extended from said plate portion to an axial direction, alternately forms projections to radial outward which are extended to a longitudinal direction, and projections to radial inward which are extended to said longitudinal direction, in a circumferential direction, and comprises depressions extended in said longitudinal direction between said adjacent projections to radial outward for being engaged with said clutch plates, and depressions extended in said longitudinal direction between said adjacent projections to radial inward, which are served as oil grooves; holding said work on an outer circumference by an outer pressing tool having an inner circumferential shape which is complementary to said outer circumference of said work; setting punches which are disposed opposite to said axial direction against an end surface of said cylindrical portion from an exterior, and inner pressing tools which are disposed opposite to a radial direction toward bottom surfaces of said oil grooves; abutting said inner pressing tools to said bottom surfaces of said oil grooves; abutting a back surface of said dams to said inner pressing tools and a front surface of said dams to said punches; pressing said cylindrical portion from said end surface to said axial direction by said punches; and flowing a material of said work between each of said punches and each of said inner pressing tools, wherein said press-molded dams are spaced from said plate portion and are slightly spaced from an end portion of said cylindrical portion of a spacing side to said plate portion side, ensure to integrate bottom surfaces and both side surfaces of said oil grooves with said dams, and are extended to radial inward, wherein said dams have a steep shape so as to retain said oil which is circulated on said oil grooves in a back surface side, and wherein an angle of said molding surface of said back surface side of said dams is in a range from 90 [deg] to 100 [deg] for a reference line parallel to a center line of said cylindrical component when said angle is measured from an exterior of said clutch hub to an interior. preparing a work which comprises a plate portion extended in a radial direction against a rotational shaft, and a cylindrical portion which is extended from said plate portion to an axial direction, alternately forms projections to radial outward which are extended to a longitudinal direction, and projections to radial inward which are extended to said longitudinal direction, in a circumferential direction, and comprises depressions extended in said longitudinal direction between said adjacent projections to radial outward for being engaged with said clutch plates, and depressions extended in said longitudinal direction between said adjacent projections to radial inward, which are served as oil grooves; holding said work on an outer circumference by an outer pressing tool having an inner circumferential shape which is complementary to said outer circumference of said work; setting punches which are disposed opposite to said axial direction against an end surface of said cylindrical portion from an exterior, and inner pressing tools which are disposed opposite to a radial direction toward bottom surfaces of said oil grooves; abutting said inner pressing tools to said bottom surfaces of said oil grooves; abutting a back surface of said dams to said inner pressing tools and a front surface of said dams to said punches; pressing said cylindrical portion from said end surface to said axial direction by said punches; and flowing a material of said work between each of said punches and each of said inner pressing tools, wherein said press-molded dams are spaced from said plate portion and are slightly spaced from an end portion of said cylindrical portion of a spacing side to said plate portion side, ensure to integrate bottom surfaces and both side surfaces of said oil grooves with said dams, and are extended to radial inward, wherein said dams have a steep shape so as to retain said oil which is circulated on said oil grooves in a back surface side, and wherein an angle of said molding surface of said back surface side of said dams is in a range from 90 [deg] to 100 [deg] for a reference line parallel to a center line of said cylindrical component when said angle is measured from an exterior of said clutch hub to an interior.