Citizen Watch Company, Ltd.

Haruko Yamazaki

Yoshiro Hirai

An object of the present invention is to provide a clock screw having a deep interference film blue color that contributes to decorativeness while also having superior scratch resistance and corrosion resistance, and a method for producing the same. The means for solving provided by the present invention consists of: a clock screw comprising a screw base material made of steel containing carbon at 0.5% by weight to 1.0% by weight, an oxide layer of the steel on the screw base material having a thickness of 60 nm to 80 nm, and a fluorine coating film on the oxide layer; and, a method for producing the clock screw comprising: a step for preparing the screw base material, a step for forming the oxide layer by heating the screw base material for 30 minutes or longer at a temperature of 300&#xb0; C. or lower in an air atmosphere, and a step for forming the fluorine coating film on the oxide layer.

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Tokyo, Japan

Haruko Yamazaki