| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a removal prevention nut and a removal prevention bolt, which can prevent a grating cover, a manhole cover or the like from being stolen, which can be easily and inexpensively manufactured and which can be rapidly and easily constructed, and to provide a socket wrench for mounting and dismounting the nut and the bolt, and a construction method using these components. <P>SOLUTION: A removal prevention nut 1 is fastened in a recessed space S, and the nut is formed into a polygonal nut shape, in which at least one corner has a removal prevention protrusion 12 formed thereon protruding outward than the corner. <P>COPYRIGHT: (C)2013,JPO&INPIT |
