PURPOSE: To improve the resisting strength of drawing a nail by working a screw such that the lead angle on the rod part is acute on the tip side and sequentially becomes obtuse toward the head side, providing a series of locking teeth directed oppositely to the drawing direction on the crest of the screw, and tapering the rod part toward the tip.

CONSTITUTION: Since the rod part is formed into a screw, a nail is driven while rotating and thereafter wooden fibers cling to the screw 5. The screw 5 is formed such that the lead angle on the tip 4 side is acute and gets obtuse sequentially toward the head 3 side. Thus, driving resistance is small while resisting strength of drawing gets large. Also, since a series of locking teeth 6 are provided on the crest of the screw 5 oppositely to the drawing direction, the screw is prevented from reversal and drawing by the reversely directed locking teeth 6 to increase a holding force when the drawing force is exerted. The outer diameter of the nail is tapered toward the tip 4. New wooden fibers cling to the screw over the whole length thereof, so that a holding force is increased.