Metallic element and slide fastener

A metal element attached to a core thread of a fastener tape, the metal element comprising:

• a pair of legs sandwiching the core thread;
• and
• a head to which the pair of legs are coupled,
• wherein:
• each leg is a cantilever extending toward its free end from its base end coupled to the head and is provided, at the free end, with a stopping claw that has a stopping surface configured to prevent the core thread from moving away from a position between the pair of legs, the stopping surfaces of the pair of legs slanting gradually so as to approach one another in a direction away from the head;
• the head is shaped like a cup with engaging protrusion and engaged recess which are arranged in a same axial line, the engaging protrusion protruding from a first side-surface of the metal element which is formed flat across the head and the leg, the engaged recess recessed in a second side-surface of the metal element which is formed flat across the head and the leg, and the second side-surface being provided at the opposite side of the first side-surface;
• the legs of the pair of legs are provided with core-thread-pressing surfaces that slant gradually so as to approach one another in a direction away from the stopping surfaces, each core-thread-pressing surface extending from the stopping surface to the base end of the leg;
• and
• a thickness of each leg in a thickness direction of the fastener tape gradually increases from the free end toward the base end of the leg in accordance with at least the slanting of the core-thread-pressing surface,
• wherein the stopping surface and the core-thread-pressing surface intersect and thereby form a corner comprising two intersecting line segments, the line segments defining an angle being in a range between 100° and 135°, and
• a length of the core-thread-pressing surface is at least 1.5 times a length of the stopping surface in a direction the legs extend away from the head.