Patent attributes
Provided are a metal double-sided tooth that prevents a flow protruding portion from protruding from the boundary between a coupling concave portion and a body, and a slide fastener using the metal double-sided tooth. The inner side of a coupling concave portion is formed in a substantially bowl shape and a concave portion is formed throughout the boundary between the coupling concave portion and a body and a front side and a rear side of the body. Further, when the metal double-sided tooth is attached to a fastener tape, it is possible to prevent a flow protruding portion generated by caulking a pair of legs from protruding outward from the coupling concave portion or the front side and the rear side of the body until sliding friction is generated in a slider.