FASTENING METHOD AND CYLINDER DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a fastening method and a cylinder device which can prevent durability degradation of a nut.SOLUTION: A nut 22 consists of a first nut 22A of a bearing surface 53A side and a second nut 22B arranged contacting with the first nut 22A in another side of the bearing surface 53A of the first nut 22A. A concavity 81B is formed in an internal circumference side of an edge face 53B of the second nut 22B at the first nut 22A side. Wall of the first nut 22A flows to extend to a hoop direction partially to a tip side of a bolt 21 and goes into the concavity 81B by a crimping step crimping an end of the first nut 22A of the second nut 22B side from an external circumference direction at several part with a punch.