| 摘要 |
A nail includes a head, a shank connected to the head and a plurality of threads defined in an outer periphery of the shank, a tip portion connected to an end of the shank, and a plurality of wings extending from the tip portion. The tip of the tip portion first penetrates through the object and the wings cut through the board and form a plurality of parts in an inner periphery of a hole into which the nail penetrates. The nail penetrates and moves through the object linearly. The threads are engaged with the parts so that the nail is firmly engaged with the board.
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