FASTENING METHOD AND CYLINDER DEVICE

摘要

A fastening method for fastening a nut to a bolt by screwing includes preparing a nut including a tool mounting portion formed on a seat surface, and an annular thin portion formed on the tool mounting portion opposite to the seat surface, swaging a plurality of places of the thin portion with punches from an outer circumferential direction, and flowing a thickness of the thin portion so as to extend to a front end of the bolt partially in a circumferential direction to be closely adhered to a screw portion of the bolt.