| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a wood screw which can sufficiently prevent a crack of a member. <P>SOLUTION: In the wood screw 1, cutting chips raked by a rake face 13 are easily gathered to the center side by forming the rake face 13 of a drill 4 at the rear side of the rotating direction A rather than a line segment B connecting an axial line X and a drill blade 11 in a cross section shape which is vertical to the axial line X. Furthermore, by making a length from the axial line X up to an edge 12 shorter than a length from the axial line X up to the internal end 13a of the rake face 13, the cutting chips can surely be gathered to the center side by the rake face 13, and the cutting chips can sequentially be sent out to a base end side accompanied by the progress of a thread 5. In such a manner, the clogging of the cutting chips in the member is prevented and the crack of the member is sufficiently prevented. <P>COPYRIGHT: (C)2013,JPO&INPIT |
