Cable bead, tire using cable bead, cable bead manufacturing method, and cable bead manufacturing device

A cable bead comprising:

• an annular core;
• and
• a first side wire spirally wrapped up around the annular core,
• wherein the annular core is formed of a round steel wire made to circle once or made, without being stranded, to circle 2 to 10 times side by side,
• the round steel wire, which forms the first side wire, continuously extends from the annular core without cutting the round steel wire that forms the annular core, and
• the cable bead satisfies 0≤(Do−Di)/Wm≤√3/2, where:
• Di (mm) is a cable bead inner radius at an inner side, along a tire width direction, of the cable bead;
• Do is a cable bead outer radius at an outer side, along the tire width direction, of the cable bead;
• and
• Wm is a maximum width of a cross section of the cable bead.