CAULKING NUT

To provide a caulking nut which can prevent or suppress the deformation of a screw hole of a nut part.SOLUTION: A caulking nut 1 comprises a nut part 2 in which a screw hole 7 is formed, and a caulking part 5 which is formed while extending in an axial direction from an end face 2a of the nut part 2. The caulking part 5 is formed into a cylindrical shape, and also formed into a tapered shape in which an external periphery is contacted in a diameter as progressing toward a tip from a base end. An external peripheral side end face 8 formed at an external peripheral side rather than the caulking part 5 is formed at the caulking part 5 side of the nut part 2, and an internal peripheral side end face 9 formed at an internal peripheral side rather than the caulking part 5 is also formed thereat. A cross-section circular arc shape outside R-part 10 for connecting an external peripheral face 5a of the caulking part 5 and the external peripheral side end face 8 is formed at a base end part of the caulking part 5, and a cross-section circular arc shape inside R-part 11 for connecting an internal peripheral face 5b of the caulking part 5 and the internal peripheral side end face 9 is also formed thereat. A radius R1 of the outside R-part 10 is set larger than a radius R2 of the inside R-part 11.SELECTED DRAWING: Figure 1 【課題】ナット部のねじ孔の変形を防止又は抑制できるカシメナットを提供する。【解決手段】カシメナット１は、ネジ穴７が形成されたナット部２と、ナット部２の端面２ａから軸方向に延びて形成されたカシメ部５とを備え、カシメ部５は、筒状に形成されると共に基端から先端に向かうにつれて外周が縮径するテーパ状に形成され、ナット部２のカシメ部５側には、カシメ部５より外周側に形成される外周側端面８が形成されると共に、カシメ部５より内周側に形成される内周側端面９が形成され、カシメ部５の基端部には、カシメ部５の外周面５ａと外周側端面８とを接続する断面円弧状の外側アール部１０が形成されると共に、カシメ部５の内周面５ｂと内周側端面９とを接続する断面円弧状の内側アール部１１が形成され、外側アール部１０の半径Ｒ１が、内側アール部１１の半径Ｒ２より大きく設定される。【選択図】図１