| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a head for a screw, which can smoothly sink into a surface layer material even when the surface layer material is composed of hard wood, and which allows an operator to naturally control excessive sinking of the head which results from excessive screwing by means of a countersinking adjusting head. <P>SOLUTION: The countersinking adjusting head is constituted by a flange portion 7 that is a top surface, a bottom surface 9 including a bottom dust collecting groove 13 and a bottom crest 14, and a side surface 11 including a side dust collecting groove 15 and a side crest 16. Thus, the surface layer material can be closely fastened, and the fastening can be performed according to the hardness of hard wood by adjusting the inclinations of the bottom surface and side surface. <P>COPYRIGHT: (C)2013,JPO&INPIT |
