PROBLEM TO BE SOLVED: To provide a looseness preventing drill bolt possible to be repeatedly used, and capable of cutting a prepared hole and a screw groove part at the same time, and secured in double-lock when finally fastening.;SOLUTION: This looseness preventing drill bolt is provided with a drill part 2 at a tip of a shank 1 with a bolt, and a material to be cut is cut by the work of the drill to form the prepared hole, and a screw part 4 is made to cut into the inner surface of the prepared hole, and furthermore, a tip of the shank 1 with a bolt is fastened by a looseness stopper fitting 6.;COPYRIGHT: (C)2003,JPO
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