An anchoring device comprises an elongated element (1) introduceable into a hole (10) and means for securing the element against withdrawal from the hole. The securing means comprise at least one part (5, 13, 16) movably connected to the elongated element (1) and adapted to project transversely beyond the periphery of the element to be brought into contact with a wall (12) of the hole. The part is adapted to move, on traction of the element (1) introduced into the hole (10) in a direction out of the hole, relative to the element (1) by means of friction generation against the hole wall (12) while increasing the combined transverse dimension of element (1) and part (5, 13, 16) to the corresponding transverse dimension of the hole and to tend to increase this combined transverse dimension further on continued traction in the element.