| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a nail from being easily turned after a display board and the like are attached with the one nail and prevent the display board and the like from being inclined rightward and leftward.SOLUTION: A cross-sectional shape of a shank of a nail is set triangular while the cross-sectional shape of the shank of the nail is conventionally circular.</p> |
