| 摘要 |
The present invention relates to a bolt-nut fastening device, improving a fastening force. According to one embodiment of the present invention, the bolt-nut fastening device comprises: a two-stage bolt composed of a body, a first bolt protruding toward one end of the body, and a second bolt protruding toward one end of the first bolt; and a double nut fastened to the two-stage bolt. The double nut comprises: a first nut fastened to the first bolt; and a second nut fastened to the second bolt and coupled to the inside of the first nut. |
