To provide a crown tightening tool which prevents a crown from being tightened with predetermined torque or more.

The crown tightening tool comprises an engagement section 11 which is engaged with the crown and an operation handle section which rotatingly operates the engagement section 11. The engagement section 11 is made of a resin material and is formed with a recess 14 which is engageable with the crown. The recess 14 comprises an engagement female section 141 which is engageable with the crown and an escape section 142 which is formed in a larger diameter than the engagement female section 141. The engagement female section 141 is formed by modeling the periphery of the crown on the spot. The escape section 142 is formed in a tapered shape extending from the end of the engagement female section 141 to the side face of the crown.

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