METHOD FOR MANUFACTURING BURRING PROCESSED ARTICLE AND BURRING PROCESSED ARTICLE

A burring processing method including increasing a diameter of a prepared hole provided in a metal component and bending a part of the metal component to form a burring processed portion (110) including an upright portion (120) and a curved portion (130), wherein in a cross-section that passes through an axis (cb) of the burring processed portion (110) and is parallel to the axis (cb) of the burring processed portion (110), a cross-sectional shape of the curved portion (130) on an inner surface of the curved portion consists of a curve, and a length of the curved portion (130) in a direction perpendicular to the axis (cb) of the burring processed portion (110) is at least 1.2 times a height of the curved portion in a direction parallel to the axis (cb) of the burring processed portion (110).