| 摘要 |
PROBLEM TO BE SOLVED: To provide a Pachinko nail easy to drive and difficult to remove. SOLUTION: Only a tip section is driven into a Pachinko base board 5, and most of a shaft section 11 including a head section 14 is exposed in this pachinko nail. A spiral groove 12 having a nearly V-shaped cross section is molded only at a driving section, and a nearly conical pointed section 15 is provided at the tip. The angleα1 between a plane perpendicular to the axis of the nail and the nail driving side face 12a of the spiral groove 12 is made larger than the angleα2 between the plane perpendicular to the axis of the nail and the nail removing side face 12b of the spiral groove 12.
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