摘要 |
Fastening elements, such as bolts, studs or nails, are inserted into a hard receiving material, such as concrete or rock, first, by drilling a blind borehole into the receiving material. The diameter of the borehole is formed so that it is greater than the diameter of the leading end of the fastening element. A setting device containing the fastening element is then aligned with the blind borehole and the fastening element is driven into the receiving material. The fastening element enters the receiving material at the base of the blind borehole. The length of the fastening element inserted into the receiving material is at least half the axial length of the borehole and may have a length considerably greater than the axial length of the borehole. |